fix: address review findings from reviews #2955 and #2958

- Convert handleResponse to package-level function (unused receiver) [#17955]
- Add clarifying comment for nil resp on transport error [#17956]
- Use consistent %w wrapping in dual-unmarshal error path [#17957]
- Add SafeError() method to APIError for safe logging [#17964]
- Enforce safe CheckRedirect policy in SetHTTPClient [#17965]
- Add tests for SafeError and SetHTTPClient enforcement

.gitea/actions/review/action.yml

@@ -104,10 +104,6 @@ inputs:
     description: 'Path to custom persona JSON file'
     required: false
     default: ''
-  action-repo:
-    description: 'Repository hosting the review-bot binary (owner/name). Defaults to rodin/review-bot on Gitea, or strat/review-bot on GitHub.'
-    required: false
-    default: ''
 
 runs:
   using: 'composite'
@@ -116,21 +112,10 @@ runs:
       id: version
       shell: bash
       run: |
-        SERVER_URL="${{ inputs.gitea-url || github.server_url }}"
-        # Detect VCS type: Gitea uses /api/v1/, GitHub uses /api/v3/
-        if echo "$SERVER_URL" | grep -qi 'gitea'; then
-          API_BASE="${SERVER_URL}/api/v1"
-          DEFAULT_ACTION_REPO="rodin/review-bot"
-        else
-          API_BASE="${SERVER_URL}/api/v3"
-          DEFAULT_ACTION_REPO="strat/review-bot"
-        fi
-        ACTION_REPO="${{ inputs.action-repo || '' }}"
-        if [ -z "$ACTION_REPO" ]; then
-          ACTION_REPO="$DEFAULT_ACTION_REPO"
-        fi
+        GITEA_URL="${{ inputs.gitea-url || github.server_url }}"
+        REPO="${{ inputs.repo || 'rodin/review-bot' }}"
         if [ "${{ inputs.version }}" = "latest" ]; then
-          VERSION=$(curl -sSf "${API_BASE}/repos/${ACTION_REPO}/releases?limit=1" \
+          VERSION=$(curl -sSf "${GITEA_URL}/api/v1/repos/${REPO}/releases?limit=1" \
             | python3 -c "import sys, json; releases = json.load(sys.stdin); print(releases[0]['tag_name'] if releases else '')")
           if [ -z "$VERSION" ]; then
             echo "Failed to determine latest version" >&2
@@ -140,8 +125,6 @@ runs:
           VERSION="${{ inputs.version }}"
         fi
         echo "version=${VERSION}" >> "$GITHUB_OUTPUT"
-        echo "action-repo=${ACTION_REPO}" >> "$GITHUB_OUTPUT"
-        echo "server-url=${SERVER_URL}" >> "$GITHUB_OUTPUT"
 
     - name: Cache review-bot binary
       id: cache
@@ -154,14 +137,14 @@ runs:
       if: steps.cache.outputs.cache-hit != 'true'
       shell: bash
       run: |
-        SERVER_URL="${{ steps.version.outputs.server-url }}"
-        ACTION_REPO="${{ steps.version.outputs.action-repo }}"
+        GITEA_URL="${{ inputs.gitea-url || github.server_url }}"
+        REPO="${{ inputs.repo || 'rodin/review-bot' }}"
         VERSION="${{ steps.version.outputs.version }}"
         BINARY="review-bot-linux-amd64"
 
-        curl -sSfL "${SERVER_URL}/${ACTION_REPO}/releases/download/${VERSION}/${BINARY}" \
+        curl -sSfL "${GITEA_URL}/${REPO}/releases/download/${VERSION}/${BINARY}" \
           -o "${{ runner.temp }}/review-bot"
-        curl -sSfL "${SERVER_URL}/${ACTION_REPO}/releases/download/${VERSION}/checksums.txt" \
+        curl -sSfL "${GITEA_URL}/${REPO}/releases/download/${VERSION}/checksums.txt" \
           -o "${{ runner.temp }}/checksums.txt"
 
         # Verify SHA-256 checksum
@@ -186,8 +169,8 @@ runs:
     - name: Run review
       shell: bash
       env:
-        GITHUB_SERVER_URL: ${{ inputs.gitea-url || github.server_url }}
-        GITHUB_REPOSITORY: ${{ inputs.repo || github.repository }}
+        GITEA_URL: ${{ inputs.gitea-url || github.server_url }}
+        GITEA_REPO: ${{ inputs.repo || github.repository }}
         PR_NUMBER: ${{ inputs.pr-number || github.event.pull_request.number }}
         REVIEWER_TOKEN: ${{ inputs.reviewer-token }}
         REVIEWER_NAME: ${{ inputs.reviewer-name }}

.github/actions/review/action.yml

@@ -104,10 +104,6 @@ inputs:
     description: 'Path to custom persona JSON file'
     required: false
     default: ''
-  action-repo:
-    description: 'Repository hosting the review-bot binary (owner/name). Defaults to rodin/review-bot on Gitea, or strat/review-bot on GitHub.'
-    required: false
-    default: ''
 
 runs:
   using: 'composite'
@@ -116,21 +112,10 @@ runs:
       id: version
       shell: bash
       run: |
-        SERVER_URL="${{ inputs.gitea-url || github.server_url }}"
-        # Detect VCS type: Gitea uses /api/v1/, GitHub uses /api/v3/
-        if echo "$SERVER_URL" | grep -qi 'gitea'; then
-          API_BASE="${SERVER_URL}/api/v1"
-          DEFAULT_ACTION_REPO="rodin/review-bot"
-        else
-          API_BASE="${SERVER_URL}/api/v3"
-          DEFAULT_ACTION_REPO="strat/review-bot"
-        fi
-        ACTION_REPO="${{ inputs.action-repo || '' }}"
-        if [ -z "$ACTION_REPO" ]; then
-          ACTION_REPO="$DEFAULT_ACTION_REPO"
-        fi
+        GITEA_URL="${{ inputs.gitea-url || github.server_url }}"
+        REPO="${{ inputs.repo || 'rodin/review-bot' }}"
         if [ "${{ inputs.version }}" = "latest" ]; then
-          VERSION=$(curl -sSf "${API_BASE}/repos/${ACTION_REPO}/releases?limit=1" \
+          VERSION=$(curl -sSf "${GITEA_URL}/api/v1/repos/${REPO}/releases?limit=1" \
             | python3 -c "import sys, json; releases = json.load(sys.stdin); print(releases[0]['tag_name'] if releases else '')")
           if [ -z "$VERSION" ]; then
             echo "Failed to determine latest version" >&2
@@ -140,8 +125,6 @@ runs:
           VERSION="${{ inputs.version }}"
         fi
         echo "version=${VERSION}" >> "$GITHUB_OUTPUT"
-        echo "action-repo=${ACTION_REPO}" >> "$GITHUB_OUTPUT"
-        echo "server-url=${SERVER_URL}" >> "$GITHUB_OUTPUT"
 
     - name: Cache review-bot binary
       id: cache
@@ -154,14 +137,14 @@ runs:
       if: steps.cache.outputs.cache-hit != 'true'
       shell: bash
       run: |
-        SERVER_URL="${{ steps.version.outputs.server-url }}"
-        ACTION_REPO="${{ steps.version.outputs.action-repo }}"
+        GITEA_URL="${{ inputs.gitea-url || github.server_url }}"
+        REPO="${{ inputs.repo || 'rodin/review-bot' }}"
         VERSION="${{ steps.version.outputs.version }}"
         BINARY="review-bot-linux-amd64"
 
-        curl -sSfL "${SERVER_URL}/${ACTION_REPO}/releases/download/${VERSION}/${BINARY}" \
+        curl -sSfL "${GITEA_URL}/${REPO}/releases/download/${VERSION}/${BINARY}" \
           -o "${{ runner.temp }}/review-bot"
-        curl -sSfL "${SERVER_URL}/${ACTION_REPO}/releases/download/${VERSION}/checksums.txt" \
+        curl -sSfL "${GITEA_URL}/${REPO}/releases/download/${VERSION}/checksums.txt" \
           -o "${{ runner.temp }}/checksums.txt"
 
         # Verify SHA-256 checksum

.github/workflows/review.yml

@@ -1,47 +0,0 @@
-# Self-review workflow for strat/review-bot on GitHub Enterprise Server.
-# Tests that the composite action runs correctly on GitHub runners:
-# - GITHUB_SERVER_URL and GITHUB_REPOSITORY env vars are set correctly
-# - Binary is downloaded from gitea.weiker.me (where releases live)
-# - Review is posted to the corresponding Gitea PR
-name: Review
-
-on:
-  pull_request:
-    types: [opened, synchronize]
-
-jobs:
-  review:
-    runs-on: ubuntu-24.04
-    if: github.event_name == 'pull_request'
-    strategy:
-      matrix:
-        include:
-          - name: sonnet
-            token_secret: SONNET_REVIEW_TOKEN
-            model: anthropic--claude-4.6-sonnet
-          - name: gpt
-            token_secret: GPT_REVIEW_TOKEN
-            model: gpt-5
-    steps:
-      - uses: actions/checkout@v4
-      - name: Run ${{ matrix.name }} review
-        uses: ./.gitea/actions/review
-        with:
-          # Download binary from Gitea (releases live there, not on GHE)
-          gitea-url: https://gitea.weiker.me
-          # Post review to the corresponding Gitea repo
-          repo: rodin/review-bot
-          reviewer-token: ${{ secrets[matrix.token_secret] }}
-          reviewer-name: ${{ matrix.name }}
-          llm-model: ${{ matrix.model }}
-          llm-provider: aicore
-          aicore-client-id: ${{ secrets.AICORE_CLIENT_ID }}
-          aicore-client-secret: ${{ secrets.AICORE_CLIENT_SECRET }}
-          aicore-auth-url: ${{ secrets.AICORE_AUTH_URL }}
-          aicore-api-url: ${{ secrets.AICORE_API_URL }}
-          aicore-resource-group: ${{ secrets.AICORE_RESOURCE_GROUP }}
-          conventions-file: CONVENTIONS.md
-          patterns-repo: rodin/go-patterns
-          patterns-files: 'README.md,patterns/'
-          dry-run: 'true'
-          timeout: '600'

gitea/adapter.go

@@ -1,232 +0,0 @@
-package gitea
-
-import (
-	"context"
-	"fmt"
-
-	"gitea.weiker.me/rodin/review-bot/vcs"
-)
-
-// Adapter wraps a gitea.Client and satisfies the vcs.Client interface.
-// It handles translation between GitHub-canonical diff positions and Gitea
-// line numbers, and between canonical review event strings and Gitea-native values.
-type Adapter struct {
-	client *Client
-}
-
-// Compile-time interface conformance assertion.
-var _ vcs.Client = (*Adapter)(nil)
-
-// NewAdapter creates a new Adapter wrapping the given gitea Client.
-func NewAdapter(client *Client) *Adapter {
-	return &Adapter{client: client}
-}
-
-// Underlying returns the wrapped gitea.Client for Gitea-specific operations
-// that have no vcs.Client equivalent (resolve comment, timeline, supersede flow).
-func (a *Adapter) Underlying() *Client {
-	return a.client
-}
-
-// --- PRReader ---
-
-// GetPullRequest maps gitea.PullRequest to vcs.PullRequest.
-func (a *Adapter) GetPullRequest(ctx context.Context, owner, repo string, number int) (*vcs.PullRequest, error) {
-	pr, err := a.client.GetPullRequest(ctx, owner, repo, number)
-	if err != nil {
-		return nil, fmt.Errorf("get pull request: %w", err)
-	}
-	return &vcs.PullRequest{
-		Number: number,
-		Title:  pr.Title,
-		Body:   pr.Body,
-		Head: vcs.HeadRef{
-			SHA: pr.Head.Sha,
-			Ref: pr.Head.Ref,
-		},
-		Base: vcs.BaseRef{
-			Ref: pr.Base.Ref,
-		},
-	}, nil
-}
-
-// GetPullRequestDiff is a pass-through to the underlying client.
-func (a *Adapter) GetPullRequestDiff(ctx context.Context, owner, repo string, number int) (string, error) {
-	return a.client.GetPullRequestDiff(ctx, owner, repo, number)
-}
-
-// GetPullRequestFiles maps []gitea.ChangedFile to []vcs.ChangedFile.
-// Patch field is omitted (zero-value) since Gitea's /pulls/{n}/files does not return patch text.
-func (a *Adapter) GetPullRequestFiles(ctx context.Context, owner, repo string, number int) ([]vcs.ChangedFile, error) {
-	files, err := a.client.GetPullRequestFiles(ctx, owner, repo, number)
-	if err != nil {
-		return nil, err
-	}
-	result := make([]vcs.ChangedFile, len(files))
-	for i, f := range files {
-		result[i] = vcs.ChangedFile{
-			Filename: f.Filename,
-			Status:   f.Status,
-		}
-	}
-	return result, nil
-}
-
-// GetFileContentAtRef is a pass-through to the underlying client.
-func (a *Adapter) GetFileContentAtRef(ctx context.Context, owner, repo, path, ref string) (string, error) {
-	return a.client.GetFileContentAtRef(ctx, owner, repo, path, ref)
-}
-
-// GetCommitStatuses maps []gitea.CommitStatus to []vcs.CommitStatus.
-func (a *Adapter) GetCommitStatuses(ctx context.Context, owner, repo, sha string) ([]vcs.CommitStatus, error) {
-	statuses, err := a.client.GetCommitStatuses(ctx, owner, repo, sha)
-	if err != nil {
-		return nil, err
-	}
-	result := make([]vcs.CommitStatus, len(statuses))
-	for i, s := range statuses {
-		result[i] = vcs.CommitStatus{
-			Status:      s.Status,
-			Context:     s.Context,
-			Description: s.Description,
-			TargetURL:   s.TargetURL,
-		}
-	}
-	return result, nil
-}
-
-// --- FileReader ---
-
-// GetFileContent delegates to the underlying client, routing to the ref-aware
-// variant when ref is non-empty.
-func (a *Adapter) GetFileContent(ctx context.Context, owner, repo, path, ref string) (string, error) {
-	if ref != "" {
-		return a.client.GetFileContentRef(ctx, owner, repo, path, ref)
-	}
-	return a.client.GetFileContent(ctx, owner, repo, path)
-}
-
-// ListContents maps []gitea.ContentEntry to []vcs.ContentEntry.
-func (a *Adapter) ListContents(ctx context.Context, owner, repo, path string) ([]vcs.ContentEntry, error) {
-	entries, err := a.client.ListContents(ctx, owner, repo, path)
-	if err != nil {
-		return nil, err
-	}
-	result := make([]vcs.ContentEntry, len(entries))
-	for i, e := range entries {
-		result[i] = vcs.ContentEntry{
-			Name: e.Name,
-			Path: e.Path,
-			Type: e.Type,
-		}
-	}
-	return result, nil
-}
-
-// --- Reviewer ---
-
-// translateEvent translates a vcs.ReviewEvent (GitHub-canonical) to a Gitea-native event string.
-func translateEvent(event vcs.ReviewEvent) string {
-	switch event {
-	case vcs.ReviewEventApprove:
-		return "APPROVED"
-	case vcs.ReviewEventRequestChanges:
-		return "REQUEST_CHANGES"
-	case vcs.ReviewEventComment:
-		return "COMMENT"
-	default:
-		// Unknown events pass through as-is. This is intentional: new event types
-		// added to vcs.ReviewEvent will still be forwarded without a code change here,
-		// and Gitea will reject truly invalid values with a clear API error.
-		return string(event)
-	}
-}
-
-// PostReview translates vcs.ReviewRequest to the Gitea-native format.
-// It fetches the PR diff, builds a position-to-line map, and translates each
-// ReviewComment.Position (GitHub diff-position) to a Gitea new_position (line number).
-func (a *Adapter) PostReview(ctx context.Context, owner, repo string, number int, req vcs.ReviewRequest) (*vcs.Review, error) {
-	event := translateEvent(req.Event)
-
-	var giteaComments []ReviewComment
-	if len(req.Comments) > 0 {
-		// Fetch diff to build position → line number map.
-		// The diff is fetched unconditionally when comments exist. This adds latency
-		// for reviews with inline comments but keeps the implementation simple — caching
-		// the diff across calls would add complexity for minimal gain since PostReview
-		// is called at most once per review cycle.
-		diff, err := a.client.GetPullRequestDiff(ctx, owner, repo, number)
-		if err != nil {
-			return nil, fmt.Errorf("fetch diff for position translation: %w", err)
-		}
-
-		posMap := BuildPositionToLineMap(diff)
-
-		for _, c := range req.Comments {
-			lineNum, err := posMap.Translate(c.Path, c.Position)
-			if err != nil {
-				return nil, fmt.Errorf("translate position %d in %s: %w", c.Position, c.Path, err)
-			}
-			// CommitID from vcs.ReviewComment is intentionally not forwarded:
-			// Gitea review comments are pinned to the PR head SHA automatically,
-			// and the CreatePullReview API has no per-comment commit_id field.
-			giteaComments = append(giteaComments, ReviewComment{
-				Path:        c.Path,
-				NewPosition: int64(lineNum),
-				Body:        c.Body,
-			})
-		}
-	}
-
-	review, err := a.client.PostReview(ctx, owner, repo, number, event, req.Body, giteaComments)
-	if err != nil {
-		return nil, fmt.Errorf("post review: %w", err)
-	}
-
-	return &vcs.Review{
-		ID:       review.ID,
-		Body:     review.Body,
-		User:     vcs.UserInfo{Login: review.User.Login},
-		State:    review.State,
-		Stale:    review.Stale,
-		CommitID: review.CommitID,
-	}, nil
-}
-
-// ListReviews maps []gitea.Review to []vcs.Review.
-func (a *Adapter) ListReviews(ctx context.Context, owner, repo string, number int) ([]vcs.Review, error) {
-	reviews, err := a.client.ListReviews(ctx, owner, repo, number)
-	if err != nil {
-		return nil, err
-	}
-	result := make([]vcs.Review, len(reviews))
-	for i, r := range reviews {
-		result[i] = vcs.Review{
-			ID:       r.ID,
-			Body:     r.Body,
-			User:     vcs.UserInfo{Login: r.User.Login},
-			State:    r.State,
-			Stale:    r.Stale,
-			CommitID: r.CommitID,
-		}
-	}
-	return result, nil
-}
-
-// DeleteReview is a pass-through to the underlying client.
-func (a *Adapter) DeleteReview(ctx context.Context, owner, repo string, number int, reviewID int64) error {
-	return a.client.DeleteReview(ctx, owner, repo, number, reviewID)
-}
-
-// DismissReview deletes the review. Gitea supports full deletion of any review state.
-// The message parameter is intentionally unused — Gitea deletion has no dismissal message.
-func (a *Adapter) DismissReview(ctx context.Context, owner, repo string, number int, reviewID int64, message string) error {
-	return a.client.DeleteReview(ctx, owner, repo, number, reviewID)
-}
-
-// --- Identity ---
-
-// GetAuthenticatedUser is a pass-through to the underlying client.
-func (a *Adapter) GetAuthenticatedUser(ctx context.Context) (string, error) {
-	return a.client.GetAuthenticatedUser(ctx)
-}

gitea/adapter_test.go

@@ -1,388 +0,0 @@
-package gitea_test
-
-import (
-	"context"
-	"encoding/json"
-	"net/http"
-	"net/http/httptest"
-	"strings"
-	"testing"
-
-	"gitea.weiker.me/rodin/review-bot/gitea"
-	"gitea.weiker.me/rodin/review-bot/vcs"
-)
-
-func TestAdapter_GetPullRequest(t *testing.T) {
-	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Type", "application/json")
-		json.NewEncoder(w).Encode(map[string]any{
-			"title": "Test PR",
-			"body":  "PR body",
-			"head": map[string]any{
-				"sha": "abc123",
-				"ref": "feature-branch",
-			},
-			"base": map[string]any{
-				"ref": "main",
-			},
-		})
-	}))
-	defer server.Close()
-
-	client := gitea.NewClient(server.URL, "token")
-	adapter := gitea.NewAdapter(client)
-
-	pr, err := adapter.GetPullRequest(context.Background(), "owner", "repo", 42)
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-	if pr.Number != 42 {
-		t.Errorf("Number = %d, want 42", pr.Number)
-	}
-	if pr.Title != "Test PR" {
-		t.Errorf("Title = %q, want %q", pr.Title, "Test PR")
-	}
-	if pr.Body != "PR body" {
-		t.Errorf("Body = %q, want %q", pr.Body, "PR body")
-	}
-	if pr.Head.SHA != "abc123" {
-		t.Errorf("Head.SHA = %q, want %q", pr.Head.SHA, "abc123")
-	}
-	if pr.Head.Ref != "feature-branch" {
-		t.Errorf("Head.Ref = %q, want %q", pr.Head.Ref, "feature-branch")
-	}
-	if pr.Base.Ref != "main" {
-		t.Errorf("Base.Ref = %q, want %q", pr.Base.Ref, "main")
-	}
-}
-
-func TestAdapter_GetPullRequestFiles(t *testing.T) {
-	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Type", "application/json")
-		json.NewEncoder(w).Encode([]map[string]any{
-			{"filename": "main.go", "status": "modified"},
-			{"filename": "new.go", "status": "added"},
-		})
-	}))
-	defer server.Close()
-
-	client := gitea.NewClient(server.URL, "token")
-	adapter := gitea.NewAdapter(client)
-
-	files, err := adapter.GetPullRequestFiles(context.Background(), "owner", "repo", 1)
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-	if len(files) != 2 {
-		t.Fatalf("got %d files, want 2", len(files))
-	}
-	if files[0].Filename != "main.go" || files[0].Status != "modified" {
-		t.Errorf("files[0] = %+v", files[0])
-	}
-	if files[1].Filename != "new.go" || files[1].Status != "added" {
-		t.Errorf("files[1] = %+v", files[1])
-	}
-}
-
-func TestAdapter_ListReviews(t *testing.T) {
-	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Type", "application/json")
-		json.NewEncoder(w).Encode([]map[string]any{
-			{
-				"id":        1,
-				"body":      "LGTM",
-				"user":      map[string]any{"login": "reviewer1"},
-				"state":     "APPROVED",
-				"stale":     false,
-				"commit_id": "abc123",
-			},
-			{
-				"id":        2,
-				"body":      "Needs work",
-				"user":      map[string]any{"login": "reviewer2"},
-				"state":     "REQUEST_CHANGES",
-				"stale":     true,
-				"commit_id": "def456",
-			},
-		})
-	}))
-	defer server.Close()
-
-	client := gitea.NewClient(server.URL, "token")
-	adapter := gitea.NewAdapter(client)
-
-	reviews, err := adapter.ListReviews(context.Background(), "owner", "repo", 1)
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-	if len(reviews) != 2 {
-		t.Fatalf("got %d reviews, want 2", len(reviews))
-	}
-	if reviews[0].ID != 1 || reviews[0].Body != "LGTM" || reviews[0].User.Login != "reviewer1" {
-		t.Errorf("reviews[0] = %+v", reviews[0])
-	}
-	if reviews[0].State != "APPROVED" || reviews[0].Stale || reviews[0].CommitID != "abc123" {
-		t.Errorf("reviews[0] state/stale/commit = %v/%v/%v", reviews[0].State, reviews[0].Stale, reviews[0].CommitID)
-	}
-	if reviews[1].ID != 2 || !reviews[1].Stale || reviews[1].State != "REQUEST_CHANGES" {
-		t.Errorf("reviews[1] = %+v", reviews[1])
-	}
-}
-
-func TestAdapter_GetCommitStatuses(t *testing.T) {
-	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Type", "application/json")
-		json.NewEncoder(w).Encode([]map[string]any{
-			{
-				"status":      "success",
-				"context":     "ci/test",
-				"description": "All tests pass",
-				"target_url":  "https://ci.example.com/1",
-			},
-		})
-	}))
-	defer server.Close()
-
-	client := gitea.NewClient(server.URL, "token")
-	adapter := gitea.NewAdapter(client)
-
-	statuses, err := adapter.GetCommitStatuses(context.Background(), "owner", "repo", "abc123")
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-	if len(statuses) != 1 {
-		t.Fatalf("got %d statuses, want 1", len(statuses))
-	}
-	if statuses[0].Status != "success" {
-		t.Errorf("Status = %q, want %q", statuses[0].Status, "success")
-	}
-	if statuses[0].Context != "ci/test" {
-		t.Errorf("Context = %q, want %q", statuses[0].Context, "ci/test")
-	}
-	if statuses[0].Description != "All tests pass" {
-		t.Errorf("Description = %q, want %q", statuses[0].Description, "All tests pass")
-	}
-	if statuses[0].TargetURL != "https://ci.example.com/1" {
-		t.Errorf("TargetURL = %q, want %q", statuses[0].TargetURL, "https://ci.example.com/1")
-	}
-}
-
-func TestAdapter_PostReview_EventTranslation(t *testing.T) {
-	tests := []struct {
-		name      string
-		event     vcs.ReviewEvent
-		wantEvent string
-	}{
-		{"APPROVE becomes APPROVED", vcs.ReviewEventApprove, "APPROVED"},
-		{"REQUEST_CHANGES stays", vcs.ReviewEventRequestChanges, "REQUEST_CHANGES"},
-		{"COMMENT stays", vcs.ReviewEventComment, "COMMENT"},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			var gotEvent string
-			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-				w.Header().Set("Content-Type", "application/json")
-				var payload struct {
-					Event string `json:"event"`
-				}
-				json.NewDecoder(r.Body).Decode(&payload)
-				gotEvent = payload.Event
-				json.NewEncoder(w).Encode(map[string]any{
-					"id":   1,
-					"body": "test",
-					"user": map[string]any{"login": "bot"},
-				})
-			}))
-			defer server.Close()
-
-			client := gitea.NewClient(server.URL, "token")
-			adapter := gitea.NewAdapter(client)
-
-			_, err := adapter.PostReview(context.Background(), "owner", "repo", 1, vcs.ReviewRequest{
-				Body:  "test",
-				Event: tt.event,
-				// No comments → no diff fetch needed
-			})
-			if err != nil {
-				t.Fatalf("unexpected error: %v", err)
-			}
-			if gotEvent != tt.wantEvent {
-				t.Errorf("event = %q, want %q", gotEvent, tt.wantEvent)
-			}
-		})
-	}
-}
-
-func TestAdapter_PostReview_WithComments_PositionTranslation(t *testing.T) {
-	diff := `diff --git a/main.go b/main.go
---- a/main.go
-+++ b/main.go
-@@ -1,3 +1,4 @@
- package main
- 
-+// new comment at line 3
- func main() {}
-`
-	var gotComments []struct {
-		Path        string `json:"path"`
-		NewPosition int64  `json:"new_position"`
-		Body        string `json:"body"`
-	}
-
-	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Type", "application/json")
-		if strings.HasSuffix(r.URL.Path, ".diff") {
-			// Diff request
-			w.Write([]byte(diff))
-			return
-		}
-		if strings.HasSuffix(r.URL.Path, "/reviews") {
-			// Review post
-			var payload struct {
-				Comments []struct {
-					Path        string `json:"path"`
-					NewPosition int64  `json:"new_position"`
-					Body        string `json:"body"`
-				} `json:"comments"`
-			}
-			json.NewDecoder(r.Body).Decode(&payload)
-			gotComments = payload.Comments
-			json.NewEncoder(w).Encode(map[string]any{
-				"id":   1,
-				"body": "review",
-				"user": map[string]any{"login": "bot"},
-			})
-			return
-		}
-		t.Errorf("unexpected request: %s %s", r.Method, r.URL.Path)
-		w.WriteHeader(http.StatusNotFound)
-	}))
-	defer server.Close()
-
-	client := gitea.NewClient(server.URL, "token")
-	adapter := gitea.NewAdapter(client)
-
-	// Position 4 in this diff is "+// new comment at line 3" → new line 3
-	_, err := adapter.PostReview(context.Background(), "owner", "repo", 1, vcs.ReviewRequest{
-		Body:  "review",
-		Event: vcs.ReviewEventRequestChanges,
-		Comments: []vcs.ReviewComment{
-			{
-				Path:     "main.go",
-				Position: 4,
-				CommitID: "abc123",
-				Body:     "needs fix",
-			},
-		},
-	})
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	if len(gotComments) != 1 {
-		t.Fatalf("got %d comments, want 1", len(gotComments))
-	}
-	if gotComments[0].Path != "main.go" {
-		t.Errorf("path = %q, want %q", gotComments[0].Path, "main.go")
-	}
-	if gotComments[0].NewPosition != 3 {
-		t.Errorf("new_position = %d, want 3", gotComments[0].NewPosition)
-	}
-	if gotComments[0].Body != "needs fix" {
-		t.Errorf("body = %q, want %q", gotComments[0].Body, "needs fix")
-	}
-}
-
-func TestAdapter_DismissReview(t *testing.T) {
-	var deleteCalled bool
-	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if r.Method == http.MethodDelete {
-			deleteCalled = true
-			w.WriteHeader(204)
-			return
-		}
-		w.WriteHeader(404)
-	}))
-	defer server.Close()
-
-	client := gitea.NewClient(server.URL, "token")
-	adapter := gitea.NewAdapter(client)
-
-	err := adapter.DismissReview(context.Background(), "owner", "repo", 1, 99, "stale review")
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-	if !deleteCalled {
-		t.Error("expected delete to be called")
-	}
-}
-
-func TestAdapter_Underlying(t *testing.T) {
-	client := gitea.NewClient("http://example.com", "token")
-	adapter := gitea.NewAdapter(client)
-	if adapter.Underlying() != client {
-		t.Error("Underlying() should return the wrapped client")
-	}
-}
-
-func TestAdapter_ListContents(t *testing.T) {
-	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Type", "application/json")
-		json.NewEncoder(w).Encode([]map[string]any{
-			{"name": "main.go", "path": "src/main.go", "type": "file"},
-			{"name": "util", "path": "src/util", "type": "dir"},
-		})
-	}))
-	defer server.Close()
-
-	client := gitea.NewClient(server.URL, "token")
-	adapter := gitea.NewAdapter(client)
-
-	entries, err := adapter.ListContents(context.Background(), "owner", "repo", "src")
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-	if len(entries) != 2 {
-		t.Fatalf("got %d entries, want 2", len(entries))
-	}
-	if entries[0].Name != "main.go" || entries[0].Type != "file" {
-		t.Errorf("entries[0] = %+v", entries[0])
-	}
-	if entries[1].Name != "util" || entries[1].Type != "dir" {
-		t.Errorf("entries[1] = %+v", entries[1])
-	}
-}
-
-func TestAdapter_GetFileContent_RefRouting(t *testing.T) {
-	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		// When ref is provided, the URL should contain ?ref=
-		if r.URL.RawQuery != "" && strings.Contains(r.URL.RawQuery, "ref=") {
-			w.Write([]byte("content-at-ref"))
-		} else {
-			w.Write([]byte("content-default"))
-		}
-	}))
-	defer server.Close()
-
-	client := gitea.NewClient(server.URL, "token")
-	adapter := gitea.NewAdapter(client)
-
-	// Empty ref → routes to GetFileContent (no ?ref= query param)
-	got, err := adapter.GetFileContent(context.Background(), "owner", "repo", "main.go", "")
-	if err != nil {
-		t.Fatalf("GetFileContent(ref=\"\"): %v", err)
-	}
-	if got != "content-default" {
-		t.Errorf("GetFileContent(ref=\"\") = %q, want %q", got, "content-default")
-	}
-
-	// Non-empty ref → routes to GetFileContentRef (with ?ref= query param)
-	got, err = adapter.GetFileContent(context.Background(), "owner", "repo", "main.go", "abc123")
-	if err != nil {
-		t.Fatalf("GetFileContent(ref=\"abc123\"): %v", err)
-	}
-	if got != "content-at-ref" {
-		t.Errorf("GetFileContent(ref=\"abc123\") = %q, want %q", got, "content-at-ref")
-	}
-}

gitea/client.go

@@ -86,9 +86,6 @@ type PullRequest struct {
 		Sha string `json:"sha"`
 		Ref string `json:"ref"`
 	} `json:"head"`
-	Base struct {
-		Ref string `json:"ref"`
-	} `json:"base"`
 }
 
 // CommitStatus represents a single CI status entry.

gitea/conformance_test.go

@@ -1,3 +1,5 @@
+//go:build phase2
+
 package gitea_test
 
 import (
@@ -5,6 +7,19 @@ import (
 	"gitea.weiker.me/rodin/review-bot/vcs"
 )
 
-// Compile-time interface conformance assertion.
-// The Adapter (not the raw Client) satisfies the full vcs.Client interface.
-var _ vcs.Client = (*gitea.Adapter)(nil)
+// Compile-time interface conformance assertions.
+// These will verify gitea.Client satisfies vcs interfaces once the Phase 2
+// adapter bridges the method signature gaps:
+//
+//   - PRReader: GetPullRequest returns *gitea.PullRequest (needs *vcs.PullRequest)
+//   - PRReader: GetPullRequestFiles returns []gitea.ChangedFile (needs []vcs.ChangedFile)
+//   - FileReader: GetFileContent lacks ref parameter
+//   - Reviewer: PostReview uses (event, body, comments) instead of vcs.ReviewRequest
+//
+// Remove the phase2 build tag once the adapter is complete.
+var (
+	_ vcs.PRReader   = (*gitea.Client)(nil)
+	_ vcs.FileReader = (*gitea.Client)(nil)
+	_ vcs.Reviewer   = (*gitea.Client)(nil)
+	_ vcs.Identity   = (*gitea.Client)(nil)
+)

gitea/position.go

@@ -1,190 +0,0 @@
-package gitea
-
-import (
-	"fmt"
-	"strconv"
-	"strings"
-)
-
-// PositionMap holds a per-file mapping of GitHub diff-position to new-file line number.
-// Position is a 1-indexed offset from the @@ hunk header line in the unified diff.
-type PositionMap struct {
-	// files maps filename → (position → new-file line number).
-	// Deletion lines are mapped to -1 (no new-file line).
-	files map[string]map[int]int
-	// maxPositions caches the highest position number per file,
-	// tracked during construction to avoid O(n) scans at translate time.
-	maxPositions map[string]int
-}
-
-// Translate converts a GitHub diff-position to a new-file line number for a given file.
-// Returns an error if the file is not in the diff or the position is out of range.
-// If the position targets a deletion line, it maps to the nearest non-deletion line below;
-// if no such line exists, returns an error.
-func (pm *PositionMap) Translate(file string, position int) (int, error) {
-	if pm == nil || pm.files == nil {
-		return 0, fmt.Errorf("empty position map")
-	}
-
-	fileMap, ok := pm.files[file]
-	if !ok {
-		return 0, fmt.Errorf("file %q not found in diff", file)
-	}
-
-	if position < 1 {
-		return 0, fmt.Errorf("position %d out of range (must be >= 1)", position)
-	}
-
-	lineNum, ok := fileMap[position]
-	if !ok {
-		return 0, fmt.Errorf("position %d out of range for file %q", position, file)
-	}
-
-	// lineNum == -1 means this position is a deletion line.
-	// Map to the nearest non-deletion line below.
-	if lineNum == -1 {
-		maxPos := pm.maxPosition(file)
-		for p := position + 1; p <= maxPos; p++ {
-			if ln, exists := fileMap[p]; exists && ln > 0 {
-				return ln, nil
-			}
-		}
-		return 0, fmt.Errorf("position %d targets a deletion line with no subsequent new-file line in %q", position, file)
-	}
-
-	return lineNum, nil
-}
-
-// maxPosition returns the highest position number for a file.
-// O(1) — the maximum is tracked during map construction.
-func (pm *PositionMap) maxPosition(file string) int {
-	return pm.maxPositions[file]
-}
-
-// BuildPositionToLineMap parses a unified diff and builds a PositionMap
-// mapping diff-position → new-file line number per file.
-//
-// Diff-position counting rules (GitHub spec):
-//   - The @@ hunk header line is position 1 for the file's first hunk
-//   - Every subsequent line increments position by 1 — context, additions, AND deletions
-//   - A new @@ hunk within the same file continues incrementing (does not reset)
-//   - Position maps to the new file line number for additions and context lines
-//   - Deletion lines have a position but no new-file line number (stored as -1)
-func BuildPositionToLineMap(diff string) *PositionMap {
-	pm := &PositionMap{
-		files:        make(map[string]map[int]int),
-		maxPositions: make(map[string]int),
-	}
-
-	lines := strings.Split(diff, "\n")
-	var currentFile string
-	var position int
-	var newLine int
-
-	for _, line := range lines {
-		// Detect new file in diff.
-		// "+++ b/" is checked before "+++ /dev/null" — the two prefixes are
-		// non-overlapping ("+++ /dev/null" does not start with "+++ b/"), so
-		// ordering is independent. Checking the common case first for clarity.
-		if strings.HasPrefix(line, "+++ b/") {
-			currentFile = strings.TrimPrefix(line, "+++ b/")
-			position = 0
-			newLine = 0
-			if pm.files[currentFile] == nil {
-				pm.files[currentFile] = make(map[int]int)
-			}
-			continue
-		}
-
-		// Deleted file: +++ /dev/null means the file is being deleted
-		if strings.HasPrefix(line, "+++ /dev/null") {
-			currentFile = ""
-			continue
-		}
-
-		// Skip --- lines (old file header)
-		if strings.HasPrefix(line, "--- ") {
-			continue
-		}
-
-		// Skip diff --git lines
-		if strings.HasPrefix(line, "diff --git") {
-			continue
-		}
-
-		// Skip index lines
-		if strings.HasPrefix(line, "index ") {
-			continue
-		}
-
-		// Binary file detection
-		if strings.HasPrefix(line, "Binary files") {
-			currentFile = ""
-			continue
-		}
-
-		// Parse hunk headers
-		if strings.HasPrefix(line, "@@") && currentFile != "" {
-			position++
-			pm.maxPositions[currentFile] = position
-			newLine = parseHunkStart(line)
-			continue
-		}
-
-		if currentFile == "" {
-			continue
-		}
-
-		// Skip "\ No newline at end of file" markers
-		if strings.HasPrefix(line, `\`) {
-			continue
-		}
-
-		// Process diff content lines
-		if strings.HasPrefix(line, "+") {
-			// Addition: has a new-file line number
-			position++
-			pm.files[currentFile][position] = newLine
-			pm.maxPositions[currentFile] = position
-			newLine++
-		} else if strings.HasPrefix(line, "-") {
-			// Deletion: has a position but no new-file line number
-			position++
-			pm.files[currentFile][position] = -1
-			pm.maxPositions[currentFile] = position
-		} else if strings.HasPrefix(line, " ") {
-			// Context line
-			position++
-			pm.files[currentFile][position] = newLine
-			pm.maxPositions[currentFile] = position
-			newLine++
-		}
-	}
-
-	return pm
-}
-
-// parseHunkStart extracts the new-file starting line number from a hunk header.
-// Format: @@ -old_start[,old_count] +new_start[,new_count] @@
-func parseHunkStart(hunkLine string) int {
-	plusIdx := strings.Index(hunkLine, "+")
-	if plusIdx < 0 {
-		return 1
-	}
-	rest := hunkLine[plusIdx+1:]
-
-	endIdx := 0
-	for endIdx < len(rest) && rest[endIdx] >= '0' && rest[endIdx] <= '9' {
-		endIdx++
-	}
-
-	if endIdx == 0 {
-		return 1
-	}
-
-	n, err := strconv.Atoi(rest[:endIdx])
-	if err != nil {
-		return 1
-	}
-	return n
-}

gitea/position_test.go

@@ -1,274 +0,0 @@
-package gitea
-
-import (
-	"testing"
-)
-
-func TestBuildPositionToLineMap_SingleHunk(t *testing.T) {
-	// @@ -16,4 +16,5 @@  ← position 1
-	// context           ← position 2, new line 16
-	//-deleted           ← position 3, no new line
-	//+added             ← position 4, new line 17
-	// context           ← position 5, new line 18
-	diff := `diff --git a/file.go b/file.go
-index abc..def 100644
---- a/file.go
-+++ b/file.go
-@@ -16,4 +16,5 @@ func example() {
- context line
--deleted line
-+added line
- context after
-`
-	pm := BuildPositionToLineMap(diff)
-
-	tests := []struct {
-		pos      int
-		wantLine int
-	}{
-		{2, 16}, // context line -> new line 16
-		{4, 17}, // added line -> new line 17
-		{5, 18}, // context after -> new line 18
-	}
-	for _, tt := range tests {
-		got, err := pm.Translate("file.go", tt.pos)
-		if err != nil {
-			t.Errorf("Translate(file.go, %d): unexpected error: %v", tt.pos, err)
-			continue
-		}
-		if got != tt.wantLine {
-			t.Errorf("Translate(file.go, %d) = %d, want %d", tt.pos, got, tt.wantLine)
-		}
-	}
-}
-
-func TestBuildPositionToLineMap_MultipleHunks(t *testing.T) {
-	diff := `diff --git a/file.go b/file.go
---- a/file.go
-+++ b/file.go
-@@ -1,3 +1,3 @@ package main
- line1
--old
-+new
-@@ -10,3 +10,4 @@ func foo() {
- func foo() {
-+	// added
- 	return
- }
-`
-	pm := BuildPositionToLineMap(diff)
-
-	tests := []struct {
-		pos      int
-		wantLine int
-	}{
-		// First hunk: @@ is pos 1
-		{2, 1},  // " line1" -> new line 1
-		{4, 2},  // "+new" -> new line 2
-		// Second hunk: @@ is pos 5 (continues from 4)
-		// Wait: first hunk has pos 1(@@ hdr), 2(" line1"), 3("-old"), 4("+new")
-		// Second hunk @@ is pos 5
-		{6, 10}, // " func foo() {" -> new line 10
-		{7, 11}, // "+\t// added" -> new line 11
-		{8, 12}, // " \treturn" -> new line 12
-		{9, 13}, // " }" -> new line 13
-	}
-	for _, tt := range tests {
-		got, err := pm.Translate("file.go", tt.pos)
-		if err != nil {
-			t.Errorf("Translate(file.go, %d): unexpected error: %v", tt.pos, err)
-			continue
-		}
-		if got != tt.wantLine {
-			t.Errorf("Translate(file.go, %d) = %d, want %d", tt.pos, got, tt.wantLine)
-		}
-	}
-}
-
-func TestBuildPositionToLineMap_DeletionTargeted(t *testing.T) {
-	diff := `diff --git a/file.go b/file.go
---- a/file.go
-+++ b/file.go
-@@ -1,4 +1,3 @@ package main
- line1
--deleted
- line3
-`
-	pm := BuildPositionToLineMap(diff)
-
-	// Position 3 is the deletion line "-deleted" — should map to nearest below
-	// Position 4 is " line3" which is new line 2
-	got, err := pm.Translate("file.go", 3)
-	if err != nil {
-		t.Fatalf("Translate(file.go, 3): unexpected error: %v", err)
-	}
-	if got != 2 {
-		t.Errorf("Translate(file.go, 3) = %d, want 2 (nearest non-deletion below)", got)
-	}
-}
-
-func TestBuildPositionToLineMap_DeletionAtEnd(t *testing.T) {
-	// If a deletion line is at the end with no subsequent non-deletion line, error
-	diff := `diff --git a/file.go b/file.go
---- a/file.go
-+++ b/file.go
-@@ -1,3 +1,2 @@ package main
- line1
- line2
--deleted at end
-`
-	pm := BuildPositionToLineMap(diff)
-
-	_, err := pm.Translate("file.go", 4)
-	if err == nil {
-		t.Error("expected error for deletion at end with no subsequent line")
-	}
-}
-
-func TestBuildPositionToLineMap_NewFile(t *testing.T) {
-	diff := `diff --git a/new.go b/new.go
-new file mode 100644
---- /dev/null
-+++ b/new.go
-@@ -0,0 +1,3 @@
-+package main
-+
-+func init() {}
-`
-	pm := BuildPositionToLineMap(diff)
-
-	tests := []struct {
-		pos      int
-		wantLine int
-	}{
-		{2, 1}, // "+package main" -> line 1
-		{3, 2}, // "+" (empty line) -> line 2
-		{4, 3}, // "+func init() {}" -> line 3
-	}
-	for _, tt := range tests {
-		got, err := pm.Translate("new.go", tt.pos)
-		if err != nil {
-			t.Errorf("Translate(new.go, %d): unexpected error: %v", tt.pos, err)
-			continue
-		}
-		if got != tt.wantLine {
-			t.Errorf("Translate(new.go, %d) = %d, want %d", tt.pos, got, tt.wantLine)
-		}
-	}
-}
-
-func TestBuildPositionToLineMap_DeletedFile(t *testing.T) {
-	diff := `diff --git a/old.go b/old.go
-deleted file mode 100644
---- a/old.go
-+++ /dev/null
-@@ -1,3 +0,0 @@
--package main
--
--func old() {}
-`
-	pm := BuildPositionToLineMap(diff)
-
-	// Deleted file has no new-file lines; positions should error
-	_, err := pm.Translate("old.go", 2)
-	if err == nil {
-		t.Error("expected error for deleted file position")
-	}
-}
-
-func TestBuildPositionToLineMap_BinaryFile(t *testing.T) {
-	diff := `diff --git a/image.png b/image.png
-Binary files /dev/null and b/image.png differ
-diff --git a/code.go b/code.go
---- a/code.go
-+++ b/code.go
-@@ -1,2 +1,3 @@
- package main
-+// added
- func main() {}
-`
-	pm := BuildPositionToLineMap(diff)
-
-	// Binary file should not be in the map
-	_, err := pm.Translate("image.png", 1)
-	if err == nil {
-		t.Error("expected error for binary file")
-	}
-
-	// code.go should still work
-	got, err := pm.Translate("code.go", 3)
-	if err != nil {
-		t.Fatalf("Translate(code.go, 3): unexpected error: %v", err)
-	}
-	if got != 2 {
-		t.Errorf("Translate(code.go, 3) = %d, want 2", got)
-	}
-}
-
-func TestBuildPositionToLineMap_OutOfRange(t *testing.T) {
-	diff := `diff --git a/file.go b/file.go
---- a/file.go
-+++ b/file.go
-@@ -1,2 +1,2 @@
- line1
--old
-+new
-`
-	pm := BuildPositionToLineMap(diff)
-
-	// Position 0 is invalid
-	_, err := pm.Translate("file.go", 0)
-	if err == nil {
-		t.Error("expected error for position 0")
-	}
-
-	// Position 5 is out of range (only positions 1-4 exist)
-	_, err = pm.Translate("file.go", 5)
-	if err == nil {
-		t.Error("expected error for position 5 (out of range)")
-	}
-
-	// Unknown file
-	_, err = pm.Translate("unknown.go", 1)
-	if err == nil {
-		t.Error("expected error for unknown file")
-	}
-}
-
-func TestBuildPositionToLineMap_MultipleFiles(t *testing.T) {
-	diff := `diff --git a/a.go b/a.go
---- a/a.go
-+++ b/a.go
-@@ -1,2 +1,3 @@
- package a
-+// file a
- func aFunc() {}
-diff --git a/b.go b/b.go
---- a/b.go
-+++ b/b.go
-@@ -1,2 +1,3 @@
- package b
-+// file b
- func bFunc() {}
-`
-	pm := BuildPositionToLineMap(diff)
-
-	// a.go: pos 3 is "+// file a" -> new line 2
-	got, err := pm.Translate("a.go", 3)
-	if err != nil {
-		t.Fatalf("Translate(a.go, 3): %v", err)
-	}
-	if got != 2 {
-		t.Errorf("Translate(a.go, 3) = %d, want 2", got)
-	}
-
-	// b.go: pos 3 is "+// file b" -> new line 2
-	// Note: position resets per file
-	got, err = pm.Translate("b.go", 3)
-	if err != nil {
-		t.Fatalf("Translate(b.go, 3): %v", err)
-	}
-	if got != 2 {
-		t.Errorf("Translate(b.go, 3) = %d, want 2", got)
-	}
-}

github/client.go

@@ -21,10 +21,6 @@ const (
 
 	// maxResponseBytes limits successful response body reads to 10 MiB.
 	maxResponseBytes = 10 * 1024 * 1024
-
-	// maxRetryAttempts is the number of times doRequest will attempt a request.
-	// The retry backoff slice must have length maxRetryAttempts-1.
-	maxRetryAttempts = 3
 )
 
 // APIError represents an HTTP error response from the GitHub API.
@@ -51,6 +47,13 @@ func (e *APIError) Error() string {
 	return fmt.Sprintf("HTTP %d: %s", e.StatusCode, body)
 }
 
+// SafeError returns the error string without response body content,
+// suitable for logging in contexts where upstream response data should
+// not be exposed.
+func (e *APIError) SafeError() string {
+	return fmt.Sprintf("HTTP %d", e.StatusCode)
+}
+
 // IsNotFound reports whether an error is an API 404 response.
 func IsNotFound(err error) bool {
 	if apiErr, ok := asAPIError(err); ok {
@@ -176,39 +179,36 @@ func (c *Client) SetHTTPClient(hc *http.Client) {
 			Timeout:       30 * time.Second,
 			CheckRedirect: defaultCheckRedirect,
 		}
+	} else if hc.CheckRedirect == nil {
+		// Enforce safe redirect policy when caller provides a client without one.
+		// The default net/http behavior follows up to 10 redirects and forwards
+		// all headers (including Authorization) to any host, which can leak
+		// credentials on cross-host redirects.
+		hc.CheckRedirect = defaultCheckRedirect
 	}
 	c.httpClient = hc
 }
 
 // SetRetryBackoff configures the retry backoff durations for testing.
 // It must be called before any goroutines issue requests.
-// The slice must have exactly maxRetryAttempts-1 entries (one delay per retry gap).
 // In production the default {1s, 2s} applies.
-func (c *Client) SetRetryBackoff(d []time.Duration) error {
-	if len(d) != maxRetryAttempts-1 {
-		return fmt.Errorf("github: backoff length %d does not match maxRetryAttempts-1 (%d)", len(d), maxRetryAttempts-1)
-	}
+func (c *Client) SetRetryBackoff(d []time.Duration) {
 	c.retryBackoff = d
-	return nil
 }
 
 // doRequest performs an HTTP request with retry on 429 rate limit responses.
 // It respects the Retry-After header when present (capped at maxRetryAfter).
 // Transport errors (network failures, context cancellation) are not retried.
 func (c *Client) doRequest(ctx context.Context, method, reqURL string, accept string) ([]byte, error) {
+	const maxAttempts = 3
 	const maxRetryAfter = 120 * time.Second
 
-	// backoff holds per-attempt delays: backoff[i] is the delay before attempt i+1.
-	// Length must be maxRetryAttempts-1 (one entry per retry gap).
-	// SetRetryBackoff validates at configuration time; the default is always valid.
-	defaultBackoff := []time.Duration{1 * time.Second, 2 * time.Second}
 	var backoff []time.Duration
-	if c.retryBackoff != nil && len(c.retryBackoff) == maxRetryAttempts-1 {
+	if c.retryBackoff != nil {
 		backoff = make([]time.Duration, len(c.retryBackoff))
 		copy(backoff, c.retryBackoff)
 	} else {
-		backoff = make([]time.Duration, len(defaultBackoff))
-		copy(backoff, defaultBackoff)
+		backoff = []time.Duration{1 * time.Second, 2 * time.Second}
 	}
 
 	// maxErrorBodyBytes limits how much of an error response body is stored.
@@ -228,7 +228,7 @@ func (c *Client) doRequest(ctx context.Context, method, reqURL string, accept st
 	}
 
 	var lastErr error
-	for attempt := 0; attempt < maxRetryAttempts; attempt++ {
+	for attempt := 0; attempt < maxAttempts; attempt++ {
 		if attempt > 0 {
 			var delay time.Duration
 			if attempt-1 < len(backoff) {
@@ -265,24 +265,21 @@ func (c *Client) doRequest(ctx context.Context, method, reqURL string, accept st
 
 		resp, err := c.httpClient.Do(req)
 		if err != nil {
+			// Transport errors (DNS, TLS, timeout) yield nil resp; no body to close.
 			return nil, fmt.Errorf("do request: %w", err)
 		}
 
-		// Capture response metadata before handleResponse takes body ownership.
-		respStatus := resp.StatusCode
-		retryAfterHeader := resp.Header.Get("Retry-After")
-
-		body, done, err := c.handleResponse(resp, maxResponseBytes, maxErrorBodyBytes)
+		body, done, err := handleResponse(resp, maxResponseBytes, maxErrorBodyBytes)
 		if done {
 			return body, err
 		}
 		lastErr = err
 
 		// Retry on 429 rate limit
-		if respStatus == http.StatusTooManyRequests && attempt < maxRetryAttempts-1 {
+		if resp.StatusCode == http.StatusTooManyRequests && attempt < maxAttempts-1 {
 			// Check for Retry-After header and override backoff if present.
 			// Supports both integer seconds (common) and HTTP-date format (RFC 7231).
-			if ra := retryAfterHeader; ra != "" {
+			if ra := resp.Header.Get("Retry-After"); ra != "" {
 				if seconds, err := strconv.Atoi(ra); err == nil && seconds > 0 {
 					delay := time.Duration(seconds) * time.Second
 					if delay > maxRetryAfter {
@@ -317,7 +314,7 @@ func (c *Client) doRequest(ctx context.Context, method, reqURL string, accept st
 // handleResponse reads and closes the response body, returning the result.
 // It uses defer to ensure the body is always closed regardless of code path.
 // Returns (body, done, err) where done=true means the caller should return immediately.
-func (c *Client) handleResponse(resp *http.Response, maxRespBytes int, maxErrBytes int) ([]byte, bool, error) {
+func handleResponse(resp *http.Response, maxRespBytes int, maxErrBytes int) ([]byte, bool, error) {
 	defer resp.Body.Close()
 
 	if resp.StatusCode >= 200 && resp.StatusCode < 300 {
@@ -326,7 +323,7 @@ func (c *Client) handleResponse(resp *http.Response, maxRespBytes int, maxErrByt
 			return nil, true, fmt.Errorf("read response body: %w", err)
 		}
 		if len(body) > maxRespBytes {
-			return nil, true, fmt.Errorf("response body exceeded %d bytes", maxRespBytes)
+			return nil, true, fmt.Errorf("response body exceeded %d bytes (truncated)", maxRespBytes)
 		}
 		return body, true, nil
 	}

github/client_test.go

@@ -83,9 +83,7 @@ func TestDoRequest_429Retry(t *testing.T) {
 
 	c := NewClient("token", srv.URL, AllowInsecureHTTP())
 	c.SetHTTPClient(srv.Client())
-	if err := c.SetRetryBackoff([]time.Duration{10 * time.Millisecond, 10 * time.Millisecond}); err != nil {
-		t.Fatalf("SetRetryBackoff: %v", err)
-	}
+	c.SetRetryBackoff([]time.Duration{10 * time.Millisecond, 10 * time.Millisecond})
 
 	body, err := c.doGet(context.Background(), srv.URL+"/test")
 	if err != nil {
@@ -110,9 +108,7 @@ func TestDoRequest_429ExhaustsRetries(t *testing.T) {
 
 	c := NewClient("token", srv.URL, AllowInsecureHTTP())
 	c.SetHTTPClient(srv.Client())
-	if err := c.SetRetryBackoff([]time.Duration{1 * time.Millisecond, 1 * time.Millisecond}); err != nil {
-		t.Fatalf("SetRetryBackoff: %v", err)
-	}
+	c.SetRetryBackoff([]time.Duration{1 * time.Millisecond, 1 * time.Millisecond})
 
 	_, err := c.doGet(context.Background(), srv.URL+"/test")
 	if err == nil {
@@ -222,9 +218,7 @@ func TestDoRequest_429RetryAfterHeader(t *testing.T) {
 	c := NewClient("token", srv.URL, AllowInsecureHTTP())
 	c.SetHTTPClient(srv.Client())
 	// Use short backoff; Retry-After should override
-	if err := c.SetRetryBackoff([]time.Duration{1 * time.Millisecond, 1 * time.Millisecond}); err != nil {
-		t.Fatalf("SetRetryBackoff: %v", err)
-	}
+	c.SetRetryBackoff([]time.Duration{1 * time.Millisecond, 1 * time.Millisecond})
 
 	start := time.Now()
 	body, err := c.doGet(context.Background(), srv.URL+"/test")
@@ -265,9 +259,7 @@ func TestDoRequest_RetryAfterDoesNotMutateBackoff(t *testing.T) {
 
 	c := NewClient("token", srv.URL, AllowInsecureHTTP())
 	c.SetHTTPClient(srv.Client())
-	if err := c.SetRetryBackoff([]time.Duration{1 * time.Millisecond, 1 * time.Millisecond}); err != nil {
-		t.Fatalf("SetRetryBackoff: %v", err)
-	}
+	c.SetRetryBackoff([]time.Duration{1 * time.Millisecond, 1 * time.Millisecond})
 
 	_, err := c.doGet(context.Background(), srv.URL+"/test")
 	if err != nil {
@@ -305,9 +297,7 @@ func TestDoRequest_429RetryAfterHTTPDate(t *testing.T) {
 
 	c := NewClient("token", srv.URL, AllowInsecureHTTP())
 	c.SetHTTPClient(srv.Client())
-	if err := c.SetRetryBackoff([]time.Duration{1 * time.Millisecond, 1 * time.Millisecond}); err != nil {
-		t.Fatalf("SetRetryBackoff: %v", err)
-	}
+	c.SetRetryBackoff([]time.Duration{1 * time.Millisecond, 1 * time.Millisecond})
 
 	start := time.Now()
 	body, err := c.doGet(context.Background(), srv.URL+"/test")
@@ -348,9 +338,7 @@ func TestDoRequest_429RetryAfterHTTPDateInPast(t *testing.T) {
 
 	c := NewClient("token", srv.URL, AllowInsecureHTTP())
 	c.SetHTTPClient(srv.Client())
-	if err := c.SetRetryBackoff([]time.Duration{5 * time.Second, 5 * time.Second}); err != nil {
-		t.Fatalf("SetRetryBackoff: %v", err)
-	}
+	c.SetRetryBackoff([]time.Duration{5 * time.Second, 5 * time.Second})
 
 	start := time.Now()
 	_, err := c.doGet(context.Background(), srv.URL+"/test")
@@ -567,28 +555,45 @@ func TestSetHTTPClient_NilRestoresDefault(t *testing.T) {
 	}
 }
 
-
-func TestSetRetryBackoff_RejectsInvalidLength(t *testing.T) {
+func TestSetHTTPClient_NilCheckRedirectEnforcesDefault(t *testing.T) {
 	c := NewClient("token", "https://api.github.com")
-
-	// Too short
-	err := c.SetRetryBackoff([]time.Duration{1 * time.Second})
-	if err == nil {
-		t.Fatal("expected error for backoff length 1")
+	// Provide a client with nil CheckRedirect — should get default policy enforced.
+	hc := &http.Client{Timeout: 5 * time.Second}
+	c.SetHTTPClient(hc)
+	if c.httpClient.CheckRedirect == nil {
+		t.Fatal("expected CheckRedirect to be enforced when caller provides nil")
 	}
-	if !strings.Contains(err.Error(), "backoff length 1") {
-		t.Errorf("unexpected error message: %v", err)
-	}
-
-	// Too long
-	err = c.SetRetryBackoff([]time.Duration{1 * time.Second, 2 * time.Second, 3 * time.Second})
-	if err == nil {
-		t.Fatal("expected error for backoff length 3")
-	}
-
-	// Correct length succeeds
-	err = c.SetRetryBackoff([]time.Duration{1 * time.Second, 2 * time.Second})
-	if err != nil {
-		t.Fatalf("unexpected error for valid backoff: %v", err)
+	if c.httpClient.Timeout != 5*time.Second {
+		t.Errorf("expected caller's timeout preserved, got %v", c.httpClient.Timeout)
+	}
+}
+
+func TestSetHTTPClient_PreservesCustomCheckRedirect(t *testing.T) {
+	c := NewClient("token", "https://api.github.com")
+	called := false
+	hc := &http.Client{
+		CheckRedirect: func(req *http.Request, via []*http.Request) error {
+			called = true
+			return nil
+		},
+	}
+	c.SetHTTPClient(hc)
+	// Invoke the redirect to verify original is preserved
+	_ = c.httpClient.CheckRedirect(nil, []*http.Request{{}})
+	if !called {
+		t.Fatal("expected custom CheckRedirect to be preserved")
+	}
+}
+
+func TestAPIError_SafeError(t *testing.T) {
+	e := &APIError{StatusCode: 403, Body: "some sensitive body content"}
+	got := e.SafeError()
+	if got != "HTTP 403" {
+		t.Errorf("SafeError() = %q, want %q", got, "HTTP 403")
+	}
+	// Ensure Error() still includes body
+	full := e.Error()
+	if full != "HTTP 403: some sensitive body content" {
+		t.Errorf("Error() = %q, unexpected", full)
 	}
 }

github/conformance_test.go

@@ -5,6 +5,9 @@ import (
 	"gitea.weiker.me/rodin/review-bot/vcs"
 )
 
-// Compile-time interface conformance assertion.
-// Verifies github.Client satisfies vcs.PRReader.
-var _ vcs.PRReader = (*github.Client)(nil)
+// Compile-time interface conformance assertions.
+// These verify github.Client satisfies vcs.PRReader and vcs.FileReader.
+var (
+	_ vcs.PRReader   = (*github.Client)(nil)
+	_ vcs.FileReader = (*github.Client)(nil)
+)

github/files.go

@@ -6,28 +6,32 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/url"
-	"path"
 	"strings"
+
+	"gitea.weiker.me/rodin/review-bot/vcs"
 )
 
+// GetFileContent fetches a file from a repo at the given ref.
+// Delegates to GetFileContentAtRef with the provided ref.
+func (c *Client) GetFileContent(ctx context.Context, owner, repo, path, ref string) (string, error) {
+	return c.GetFileContentAtRef(ctx, owner, repo, path, ref)
+}
+
 // GetFileContentAtRef fetches a file at a specific ref from a repo.
 // If ref is empty, the query parameter is omitted (uses default branch).
 //
-// Returns an error if the path contains dot-segments (".", "..") or
-// attempts to traverse above the repository root.
-func (c *Client) GetFileContentAtRef(ctx context.Context, owner, repo, filePath, ref string) (string, error) {
-	escaped, err := escapePath(filePath)
-	if err != nil {
-		return "", fmt.Errorf("invalid file path: %w", err)
-	}
+// Note: dot-segments ("." and "..") in the path are silently removed to
+// prevent path traversal. This means a path like "foo/../bar" resolves
+// to "foo/bar" rather than "bar".
+func (c *Client) GetFileContentAtRef(ctx context.Context, owner, repo, path, ref string) (string, error) {
 	reqURL := fmt.Sprintf("%s/repos/%s/%s/contents/%s",
-		c.baseURL, url.PathEscape(owner), url.PathEscape(repo), escaped)
+		c.baseURL, url.PathEscape(owner), url.PathEscape(repo), escapePath(path))
 	if ref != "" {
 		reqURL += "?ref=" + url.QueryEscape(ref)
 	}
 	body, err := c.doGet(ctx, reqURL)
 	if err != nil {
-		return "", fmt.Errorf("fetch file %s: %w", filePath, err)
+		return "", fmt.Errorf("fetch file %s: %w", path, err)
 	}
 	var resp struct {
 		Content  string `json:"content"`
@@ -37,64 +41,95 @@ func (c *Client) GetFileContentAtRef(ctx context.Context, owner, repo, filePath,
 		return "", fmt.Errorf("parse file content JSON: %w", err)
 	}
 	if resp.Encoding != "base64" {
-		return "", fmt.Errorf("unexpected encoding %q for file %s", resp.Encoding, filePath)
+		return "", fmt.Errorf("unexpected encoding %q for file %s", resp.Encoding, path)
 	}
 	decoded, err := decodeBase64Content(resp.Content)
 	if err != nil {
-		return "", fmt.Errorf("decode base64 content for %s: %w", filePath, err)
+		return "", fmt.Errorf("decode base64 content for %s: %w", path, err)
 	}
 	return decoded, nil
 }
 
-// escapePath validates and encodes a slash-separated file path for use in
-// GitHub API URLs. Returns an error if the path contains dot-segments ("."
-// or "..") or resolves to a path outside the repository root.
-func escapePath(p string) (string, error) {
-	// Reject paths containing dot-segments rather than silently rewriting them.
-	for _, seg := range strings.Split(p, "/") {
-		if seg == "." || seg == ".." {
-			return "", fmt.Errorf("path contains dot-segment %q: %s", seg, p)
-		}
+// ListContents lists files and directories at a given path in a repo.
+// Returns the directory listing from the GitHub contents API.
+// If the path points to a single file (not a directory), the API returns
+// a JSON object instead of an array; this is handled by returning a
+// single-element slice.
+//
+// Note: dot-segments ("." and "..") in the path are silently removed to
+// prevent path traversal. This means a path like "foo/../bar" resolves
+// to "foo/bar" rather than "bar".
+func (c *Client) ListContents(ctx context.Context, owner, repo, path string) ([]vcs.ContentEntry, error) {
+	reqURL := fmt.Sprintf("%s/repos/%s/%s/contents/%s",
+		c.baseURL, url.PathEscape(owner), url.PathEscape(repo), escapePath(path))
+	body, err := c.doGet(ctx, reqURL)
+	if err != nil {
+		return nil, fmt.Errorf("list contents %s: %w", path, err)
 	}
 
-	// Use path.Clean for canonical form, then verify it doesn't escape root.
-	cleaned := path.Clean(p)
-	if cleaned == "." || strings.HasPrefix(cleaned, "..") {
-		return "", fmt.Errorf("path resolves outside repository root: %s", p)
+	type entry struct {
+		Name string `json:"name"`
+		Path string `json:"path"`
+		Type string `json:"type"`
 	}
 
-	// Encode each segment individually.
-	parts := strings.Split(cleaned, "/")
-	var encoded []string
-	for _, part := range parts {
-		if part == "" {
-			continue
+	// The GitHub contents API returns an array for directories and an object
+	// for single files. Try array first (common case), then fall back to object.
+	// An empty array ([]) is valid — it represents an empty directory — and
+	// results in a zero-length slice returned without error.
+	var entries []entry
+	if err := json.Unmarshal(body, &entries); err != nil {
+		var single entry
+		if err2 := json.Unmarshal(body, &single); err2 != nil {
+			return nil, fmt.Errorf("parse contents JSON: as array: %w; as object: %w", err, err2)
 		}
-		encoded = append(encoded, url.PathEscape(part))
+		// Guard against empty objects ({}) or unexpected shapes that
+		// unmarshal successfully but carry no useful data.
+		if single.Name == "" && single.Path == "" && single.Type == "" {
+			return nil, fmt.Errorf("parse contents JSON: unexpected response format")
+		}
+		entries = []entry{single}
 	}
-	return strings.Join(encoded, "/"), nil
+
+	result := make([]vcs.ContentEntry, len(entries))
+	for i, e := range entries {
+		result[i] = vcs.ContentEntry{
+			Name: e.Name,
+			Path: e.Path,
+			Type: e.Type,
+		}
+	}
+	return result, nil
 }
 
-// maxFileContentSize is the maximum decoded file size (10 MB) to prevent
-// resource exhaustion when decoding base64 content from the API.
-const maxFileContentSize = 10 * 1024 * 1024
+// escapePath escapes each segment of a relative file path for use in URLs.
+// Slashes are preserved as path separators; other special characters are escaped.
+// Dot-segments ("." and "..") and empty segments (from consecutive slashes like
+// "a//b") are silently removed to prevent path traversal and produce canonical
+// paths. This is intentional: callers may receive a different path than requested
+// without error. The function is package-private, and all callers
+// (GetFileContentAtRef, ListContents) already handle missing-file errors from the
+// API if the cleaned path doesn't match what the caller intended.
+func escapePath(p string) string {
+	parts := strings.Split(p, "/")
+	var clean []string
+	for _, part := range parts {
+		if part == "." || part == ".." || part == "" {
+			continue
+		}
+		clean = append(clean, url.PathEscape(part))
+	}
+	return strings.Join(clean, "/")
+}
 
 // decodeBase64Content decodes base64-encoded content from the GitHub contents API.
 // GitHub returns base64 content with line breaks for formatting; we strip \r and \n before decoding.
-// Returns an error if the decoded content exceeds maxFileContentSize.
 func decodeBase64Content(encoded string) (string, error) {
+	// GitHub inserts newlines in base64 content
 	cleaned := strings.NewReplacer("\n", "", "\r", "").Replace(encoded)
-	// Check estimated decoded size before allocating.
-	// Base64 encodes 3 bytes into 4 chars, so decoded ~ len*3/4.
-	if len(cleaned)*3/4 > maxFileContentSize {
-		return "", fmt.Errorf("file content too large: estimated %d bytes exceeds limit of %d", len(cleaned)*3/4, maxFileContentSize)
-	}
 	decoded, err := base64.StdEncoding.DecodeString(cleaned)
 	if err != nil {
 		return "", err
 	}
-	if len(decoded) > maxFileContentSize {
-		return "", fmt.Errorf("file content too large: %d bytes exceeds limit of %d", len(decoded), maxFileContentSize)
-	}
 	return string(decoded), nil
 }

github/files_test.go

@@ -2,95 +2,333 @@ package github
 
 import (
 	"context"
+	"encoding/json"
 	"net/http"
 	"net/http/httptest"
-	"strings"
 	"testing"
+	"time"
 )
 
-func TestEscapePath_ValidPaths(t *testing.T) {
-	t.Parallel()
-	tests := []struct {
-		name string
-		path string
-		want string
-	}{
-		{"simple file", "file.go", "file.go"},
-		{"nested path", "path/to/file.go", "path/to/file.go"},
-		{"special chars", "path/to/my file.go", "path/to/my%20file.go"},
-		{"leading slash stripped", "/path/to/file.go", "path/to/file.go"},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			t.Parallel()
-			got, err := escapePath(tt.path)
-			if err != nil {
-				t.Fatalf("unexpected error: %v", err)
-			}
-			if got != tt.want {
-				t.Errorf("escapePath(%q) = %q, want %q", tt.path, got, tt.want)
-			}
-		})
-	}
-}
-
-func TestEscapePath_DotSegments(t *testing.T) {
-	t.Parallel()
-	tests := []struct {
-		name string
-		path string
-	}{
-		{"single dot", "./file.go"},
-		{"double dot", "../file.go"},
-		{"dot in middle", "path/./file.go"},
-		{"parent traversal", "path/../file.go"},
-		{"only dots", ".."},
-		{"nested parent traversal", "a/b/../../c"},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			t.Parallel()
-			_, err := escapePath(tt.path)
-			if err == nil {
-				t.Fatalf("expected error for path %q, got nil", tt.path)
-			}
-			if !strings.Contains(err.Error(), "dot-segment") {
-				t.Errorf("expected error about dot-segment, got: %v", err)
-			}
-		})
-	}
-}
-
-func TestGetFileContentAtRef_DotSegmentError(t *testing.T) {
-	// Server should never be called — the error is caught before the request.
+func TestGetFileContent_DelegatesToGetFileContentAtRef(t *testing.T) {
+	var gotRef string
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		t.Fatal("server should not have been called")
+		gotRef = r.URL.Query().Get("ref")
+		json.NewEncoder(w).Encode(map[string]string{
+			"content":  "dGVzdA==", // "test" in base64
+			"encoding": "base64",
+		})
 	}))
 	defer srv.Close()
 
-	c := NewClient("token", srv.URL)
-	_, err := c.GetFileContentAtRef(context.Background(), "owner", "repo", "foo/../bar.go", "main")
-	if err == nil {
-		t.Fatal("expected error for path with dot-segments")
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	// Call with empty ref — should not include ref param
+	content, err := c.GetFileContent(context.Background(), "owner", "repo", "file.go", "")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
 	}
-	if !strings.Contains(err.Error(), "invalid file path") {
-		t.Errorf("expected 'invalid file path' error, got: %v", err)
+	if content != "test" {
+		t.Errorf("expected 'test', got %q", content)
+	}
+	if gotRef != "" {
+		t.Errorf("expected empty ref, got %q", gotRef)
 	}
 }
 
-func TestDecodeBase64Content_SizeLimit(t *testing.T) {
-	t.Parallel()
-	// Create base64 content that would decode to > maxFileContentSize.
-	// maxFileContentSize is 10MB. Base64 of 11MB worth of zeros.
-	// We just need something big enough to trigger the estimated size check.
-	// 14MB of base64 chars (decodes to ~10.5MB).
-	huge := strings.Repeat("A", 14*1024*1024)
-	_, err := decodeBase64Content(huge)
-	if err == nil {
-		t.Fatal("expected error for oversized content")
+func TestGetFileContent_WithRef(t *testing.T) {
+	var gotRef string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotRef = r.URL.Query().Get("ref")
+		json.NewEncoder(w).Encode(map[string]string{
+			"content":  "dGVzdA==",
+			"encoding": "base64",
+		})
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetFileContent(context.Background(), "owner", "repo", "file.go", "abc123")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
 	}
-	if !strings.Contains(err.Error(), "too large") {
-		t.Errorf("expected 'too large' error, got: %v", err)
+	if gotRef != "abc123" {
+		t.Errorf("expected ref 'abc123', got %q", gotRef)
 	}
 }
 
+func TestGetFileContent_404(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(404)
+		w.Write([]byte(`{"message":"Not Found"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetFileContent(context.Background(), "owner", "repo", "missing.go", "")
+	if err == nil {
+		t.Fatal("expected error for 404")
+	}
+}
+
+func TestGetFileContent_401(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(401)
+		w.Write([]byte(`{"message":"Bad credentials"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetFileContent(context.Background(), "owner", "repo", "file.go", "")
+	if err == nil {
+		t.Fatal("expected error for 401")
+	}
+}
+
+func TestGetFileContent_429Retry(t *testing.T) {
+	attempts := 0
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		attempts++
+		if attempts == 1 {
+			w.WriteHeader(429)
+			w.Write([]byte(`{"message":"rate limit"}`))
+			return
+		}
+		json.NewEncoder(w).Encode(map[string]string{
+			"content":  "b2s=",
+			"encoding": "base64",
+		})
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+	c.SetRetryBackoff([]time.Duration{1 * time.Millisecond})
+
+	content, err := c.GetFileContent(context.Background(), "owner", "repo", "file.go", "")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if content != "ok" {
+		t.Errorf("expected 'ok', got %q", content)
+	}
+	if attempts != 2 {
+		t.Errorf("expected 2 attempts, got %d", attempts)
+	}
+}
+
+func TestGetFileContent_MalformedJSON(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(200)
+		w.Write([]byte(`not json`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetFileContent(context.Background(), "owner", "repo", "file.go", "")
+	if err == nil {
+		t.Fatal("expected error for malformed JSON")
+	}
+}
+
+func TestListContents_HappyPath(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/repos/owner/repo/contents/src" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+		json.NewEncoder(w).Encode([]map[string]string{
+			{"name": "main.go", "path": "src/main.go", "type": "file"},
+			{"name": "lib", "path": "src/lib", "type": "dir"},
+		})
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	entries, err := c.ListContents(context.Background(), "owner", "repo", "src")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(entries) != 2 {
+		t.Fatalf("expected 2 entries, got %d", len(entries))
+	}
+	if entries[0].Name != "main.go" {
+		t.Errorf("expected name 'main.go', got %q", entries[0].Name)
+	}
+	if entries[0].Path != "src/main.go" {
+		t.Errorf("expected path 'src/main.go', got %q", entries[0].Path)
+	}
+	if entries[0].Type != "file" {
+		t.Errorf("expected type 'file', got %q", entries[0].Type)
+	}
+	if entries[1].Name != "lib" {
+		t.Errorf("expected name 'lib', got %q", entries[1].Name)
+	}
+	if entries[1].Type != "dir" {
+		t.Errorf("expected type 'dir', got %q", entries[1].Type)
+	}
+}
+
+func TestListContents_404(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(404)
+		w.Write([]byte(`{"message":"Not Found"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.ListContents(context.Background(), "owner", "repo", "missing")
+	if err == nil {
+		t.Fatal("expected error for 404")
+	}
+}
+
+func TestListContents_401(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(401)
+		w.Write([]byte(`{"message":"Bad credentials"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.ListContents(context.Background(), "owner", "repo", "src")
+	if err == nil {
+		t.Fatal("expected error for 401")
+	}
+}
+
+func TestListContents_429Retry(t *testing.T) {
+	attempts := 0
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		attempts++
+		if attempts == 1 {
+			w.WriteHeader(429)
+			w.Write([]byte(`{"message":"rate limit"}`))
+			return
+		}
+		json.NewEncoder(w).Encode([]map[string]string{
+			{"name": "file.go", "path": "file.go", "type": "file"},
+		})
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+	c.SetRetryBackoff([]time.Duration{1 * time.Millisecond})
+
+	entries, err := c.ListContents(context.Background(), "owner", "repo", ".")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(entries) != 1 {
+		t.Fatalf("expected 1 entry, got %d", len(entries))
+	}
+	if attempts != 2 {
+		t.Errorf("expected 2 attempts, got %d", attempts)
+	}
+}
+
+func TestListContents_MalformedJSON(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(200)
+		w.Write([]byte(`not json`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.ListContents(context.Background(), "owner", "repo", "src")
+	if err == nil {
+		t.Fatal("expected error for malformed JSON")
+	}
+}
+
+func TestDecodeBase64Content(t *testing.T) {
+	// Test with newlines (GitHub's format)
+	encoded := "cGFja2FnZSBt\nYWlu"
+	decoded, err := decodeBase64Content(encoded)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if decoded != "package main" {
+		t.Errorf("expected 'package main', got %q", decoded)
+	}
+}
+
+func TestDecodeBase64Content_Invalid(t *testing.T) {
+	_, err := decodeBase64Content("not!!!valid!!!base64")
+	if err == nil {
+		t.Fatal("expected error for invalid base64")
+	}
+}
+
+func TestEscapePath_RejectsDotSegments(t *testing.T) {
+	tests := []struct {
+		input string
+		want  string
+	}{
+		{"src/main.go", "src/main.go"},
+		{"../etc/passwd", "etc/passwd"},
+		{"./src/../main.go", "src/main.go"},
+		{"a/b/c", "a/b/c"},
+		{"file with spaces.go", "file%20with%20spaces.go"},
+		{"a/./b/../c", "a/b/c"},
+	}
+	for _, tt := range tests {
+		got := escapePath(tt.input)
+		if got != tt.want {
+			t.Errorf("escapePath(%q) = %q, want %q", tt.input, got, tt.want)
+		}
+	}
+}
+
+func TestDecodeBase64Content_CRLF(t *testing.T) {
+	// Base64 of "hello world" with CRLF line breaks inserted
+	encoded := "aGVs\r\nbG8g\r\nd29y\r\nbGQ="
+	decoded, err := decodeBase64Content(encoded)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if decoded != "hello world" {
+		t.Errorf("expected 'hello world', got %q", decoded)
+	}
+}
+
+func TestListContents_SingleFile(t *testing.T) {
+	// GitHub Contents API returns a JSON object (not array) for single-file paths
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(200)
+		w.Write([]byte(`{"name":"README.md","path":"README.md","type":"file"}`))
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+	entries, err := c.ListContents(context.Background(), "owner", "repo", "README.md")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(entries) != 1 {
+		t.Fatalf("expected 1 entry, got %d", len(entries))
+	}
+	if entries[0].Name != "README.md" {
+		t.Errorf("expected name 'README.md', got %q", entries[0].Name)
+	}
+	if entries[0].Type != "file" {
+		t.Errorf("expected type 'file', got %q", entries[0].Type)
+	}
+}

github/pr.go

@@ -51,10 +51,7 @@ type checkRunsResponse struct {
 	} `json:"check_runs"`
 }
 
-// GetPullRequest fetches PR metadata from the GitHub API.
-// Returns an *APIError wrapping the HTTP status on non-2xx responses (e.g.
-// IsNotFound for 404, IsUnauthorized for 401). Network and context errors
-// are wrapped but not typed as *APIError.
+// GetPullRequest fetches PR metadata.
 func (c *Client) GetPullRequest(ctx context.Context, owner, repo string, number int) (*vcs.PullRequest, error) {
 	reqURL := fmt.Sprintf("%s/repos/%s/%s/pulls/%d", c.baseURL, url.PathEscape(owner), url.PathEscape(repo), number)
 	body, err := c.doGet(ctx, reqURL)
@@ -85,15 +82,9 @@ func (c *Client) GetPullRequestDiff(ctx context.Context, owner, repo string, num
 	return string(body), nil
 }
 
-const (
-	// maxFilesPages is the upper bound on pagination loops for PR file listing,
-	// preventing unbounded iteration if the server always returns a full page.
-	maxFilesPages = 100
-
-	// maxCheckRunPages is the upper bound on pagination loops for check-run listing,
-	// preventing unbounded iteration if the server always returns a full page.
-	maxCheckRunPages = 100
-)
+// maxPages is the upper bound on pagination loops to prevent unbounded iteration
+// in case the server returns a full page indefinitely.
+const maxPages = 100
 
 // GetPullRequestFiles fetches the list of files changed in a PR.
 // Paginates through all pages (100 per page) to collect all files.
@@ -102,7 +93,7 @@ const (
 func (c *Client) GetPullRequestFiles(ctx context.Context, owner, repo string, number int) ([]vcs.ChangedFile, error) {
 	var allFiles []vcs.ChangedFile
 
-	for page := 1; page <= maxFilesPages; page++ {
+	for page := 1; page <= maxPages; page++ {
 		reqURL := fmt.Sprintf("%s/repos/%s/%s/pulls/%d/files?per_page=100&page=%d",
 			c.baseURL, url.PathEscape(owner), url.PathEscape(repo), number, page)
 		body, err := c.doGet(ctx, reqURL)
@@ -163,7 +154,7 @@ func (c *Client) GetCommitStatuses(ctx context.Context, owner, repo, sha string)
 	}
 
 	// Fetch check runs (paginated)
-	for checkPage := 1; checkPage <= maxCheckRunPages; checkPage++ {
+	for checkPage := 1; checkPage <= maxPages; checkPage++ {
 		checkURL := fmt.Sprintf("%s/repos/%s/%s/commits/%s/check-runs?per_page=100&page=%d",
 			c.baseURL, url.PathEscape(owner), url.PathEscape(repo), url.PathEscape(sha), checkPage)
 		checkBody, err := c.doGet(ctx, checkURL)
@@ -178,7 +169,7 @@ func (c *Client) GetCommitStatuses(ctx context.Context, owner, repo, sha string)
 			result = append(result, vcs.CommitStatus{
 				Context:     cr.Name,
 				Status:      mapCheckRunStatus(cr.Conclusion),
-				Description: "", // check runs have no human-readable description; conclusion is captured in Status
+				Description: derefString(cr.Conclusion),
 				TargetURL:   cr.HTMLURL,
 			})
 		}
@@ -190,17 +181,9 @@ func (c *Client) GetCommitStatuses(ctx context.Context, owner, repo, sha string)
 	return result, nil
 }
 
-// mapCheckRunStatus maps a GitHub check run conclusion to a vcs.CommitStatus status string.
+// mapCheckRunStatus maps a check run conclusion to a vcs.CommitStatus status string.
 // Conclusion alone determines the mapped state: nil conclusion means the run is
 // still in progress (pending), regardless of the status field value.
-//
-// Mapping rules:
-//   - nil → "pending" (run still in progress or queued)
-//   - "success" → "success"
-//   - "failure", "action_required", "timed_out" → "failure"
-//   - "cancelled", "skipped", "neutral" → "success" (non-blocking per GitHub check suite semantics)
-//   - "stale" → "pending" (check run became stale before completing)
-//   - unknown values → "pending" (conservative: treat unrecognized conclusions as incomplete)
 func mapCheckRunStatus(conclusion *string) string {
 	if conclusion == nil {
 		// Still running or queued
@@ -213,10 +196,17 @@ func mapCheckRunStatus(conclusion *string) string {
 		return "failure"
 	case "cancelled", "skipped", "neutral":
 		return "success" // non-blocking: these do not indicate a blocking failure per GitHub check suite semantics
-	case "stale":
+	case "stale", "waiting":
 		return "pending"
 	default:
 		return "pending"
 	}
 }
 
+// derefString safely dereferences a string pointer, returning empty string if nil.
+func derefString(s *string) string {
+	if s == nil {
+		return ""
+	}
+	return *s
+}

github/pr_test.go

@@ -545,7 +545,6 @@ func TestGetCommitStatuses_CheckRunConclusions(t *testing.T) {
 			name = *tt.conclusion
 		}
 		t.Run(name, func(t *testing.T) {
-			t.Parallel()
 			srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 				if strings.Contains(r.URL.Path, "/status") {
 					json.NewEncoder(w).Encode(map[string]interface{}{
@@ -633,44 +632,6 @@ func TestGetCommitStatuses_MalformedJSON(t *testing.T) {
 	}
 }
 
-func TestGetCommitStatuses_CheckRunsErrorAfterStatusesSucceed(t *testing.T) {
-	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		switch {
-		case strings.Contains(r.URL.Path, "/status"):
-			// Statuses succeed
-			json.NewEncoder(w).Encode(map[string]interface{}{
-				"state": "success",
-				"statuses": []map[string]string{
-					{
-						"context":     "ci/build",
-						"state":       "success",
-						"description": "Build passed",
-						"target_url":  "https://ci.example.com/1",
-					},
-				},
-			})
-		case strings.Contains(r.URL.Path, "/check-runs"):
-			// Check runs fail with 500
-			w.WriteHeader(500)
-			w.Write([]byte(`{"message":"Internal Server Error"}`))
-		default:
-			w.WriteHeader(404)
-		}
-	}))
-	defer srv.Close()
-
-	c := NewClient("token", srv.URL, AllowInsecureHTTP())
-	c.SetHTTPClient(srv.Client())
-
-	_, err := c.GetCommitStatuses(context.Background(), "owner", "repo", "abc123")
-	if err == nil {
-		t.Fatal("expected error when check-runs endpoint fails after statuses succeed")
-	}
-	if !strings.Contains(err.Error(), "fetch check runs") {
-		t.Errorf("expected check runs error, got: %v", err)
-	}
-}
-
 func stringPtr(s string) *string {
 	return &s
 }

vcs/check_test.go

@@ -1,3 +1,5 @@
+//go:build phase2
+
 package vcs_test
 
 import (
@@ -5,7 +7,21 @@ import (
 	"gitea.weiker.me/rodin/review-bot/vcs"
 )
 
-// Compile-time assertion: the gitea.Adapter satisfies vcs.Client.
-// (The raw gitea.Client does NOT satisfy vcs.Client due to signature differences;
-// the Adapter bridges them.)
-var _ vcs.Client = (*gitea.Adapter)(nil)
+// Compile-time assertion: documents the gap between gitea.Client and vcs.Client.
+// Guarded by the "phase2" build tag — enable once the Gitea adapter bridges these gaps:
+//
+//  1. PostReview signature mismatch:
+//     gitea.Client:  PostReview(ctx, owner, repo, number, event, body string, comments []gitea.ReviewComment)
+//     vcs.Reviewer:  PostReview(ctx, owner, repo, number, req vcs.ReviewRequest)
+//
+//  2. GetFileContent signature mismatch:
+//     gitea.Client:  GetFileContent(ctx, owner, repo, filepath string)  [no ref; uses default branch]
+//     vcs.FileReader: GetFileContent(ctx, owner, repo, path, ref string)
+//     (gitea.Client has GetFileContentRef for the ref variant)
+//
+//  3. ReviewComment type mismatch:
+//     gitea.ReviewComment uses NewPosition int64 (Gitea line-number convention)
+//     vcs.ReviewComment uses Position int (GitHub diff-position convention)
+//
+// The Gitea adapter (Phase 2) will wrap gitea.Client to bridge these gaps.
+var _ vcs.Client = (*gitea.Client)(nil)