review-bot/github/client_test.go

package github

import (
	"context"
	"errors"
	"net/http"
	"net/http/httptest"
	"net/url"
	"strings"
	"testing"
	"time"
)

func TestNewClient_DefaultBaseURL(t *testing.T) {
	c := NewClient("test-token", "")
	if c.baseURL != "https://api.github.com" {
		t.Errorf("expected default base URL, got %q", c.baseURL)
	}
}

func TestNewClient_CustomBaseURL(t *testing.T) {
	c := NewClient("test-token", "https://github.concur.com/api/v3")
	if c.baseURL != "https://github.concur.com/api/v3" {
		t.Errorf("expected custom base URL, got %q", c.baseURL)
	}
}

func TestNewClient_TrimsTrailingSlash(t *testing.T) {
	c := NewClient("test-token", "https://github.concur.com/api/v3/")
	if c.baseURL != "https://github.concur.com/api/v3" {
		t.Errorf("expected trailing slash trimmed, got %q", c.baseURL)
	}
}

func TestDoRequest_SetsAuthHeader(t *testing.T) {
	var gotAuth string
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		gotAuth = r.Header.Get("Authorization")
		w.WriteHeader(200)
		w.Write([]byte("{}"))
	}))
	defer srv.Close()

	c := NewClient("my-token", srv.URL, AllowInsecureHTTP())
	c.SetHTTPClient(srv.Client())
	_, _ = c.doGet(context.Background(), srv.URL+"/test")

	if gotAuth != "Bearer my-token" {
		t.Errorf("expected Bearer auth, got %q", gotAuth)
	}
}

func TestDoRequest_SetsDefaultAcceptHeader(t *testing.T) {
	var gotAccept string
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		gotAccept = r.Header.Get("Accept")
		w.WriteHeader(200)
		w.Write([]byte("{}"))
	}))
	defer srv.Close()

	c := NewClient("token", srv.URL, AllowInsecureHTTP())
	c.SetHTTPClient(srv.Client())
	_, _ = c.doGet(context.Background(), srv.URL+"/test")

	if gotAccept != "application/vnd.github+json" {
		t.Errorf("expected default Accept header, got %q", gotAccept)
	}
}

func TestDoRequest_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
		}
		w.WriteHeader(200)
		w.Write([]byte(`{"ok":true}`))
	}))
	defer srv.Close()

	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)
	}

	body, err := c.doGet(context.Background(), srv.URL+"/test")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if string(body) != `{"ok":true}` {
		t.Errorf("unexpected body: %s", body)
	}
	if attempts != 2 {
		t.Errorf("expected 2 attempts, got %d", attempts)
	}
}

func TestDoRequest_429ExhaustsRetries(t *testing.T) {
	attempts := 0
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		attempts++
		w.WriteHeader(429)
		w.Write([]byte(`{"message":"rate limit"}`))
	}))
	defer srv.Close()

	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)
	}

	_, err := c.doGet(context.Background(), srv.URL+"/test")
	if err == nil {
		t.Fatal("expected error after exhausting retries")
	}
	apiErr, ok := err.(*APIError)
	if !ok {
		t.Fatalf("expected *APIError, got %T", err)
	}
	if apiErr.StatusCode != 429 {
		t.Errorf("expected 429, got %d", apiErr.StatusCode)
	}
	if attempts != 3 {
		t.Errorf("expected 3 attempts, got %d", attempts)
	}
}

func TestDoRequest_404NoRetry(t *testing.T) {
	attempts := 0
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		attempts++
		w.WriteHeader(404)
		w.Write([]byte(`{"message":"not found"}`))
	}))
	defer srv.Close()

	c := NewClient("token", srv.URL, AllowInsecureHTTP())
	c.SetHTTPClient(srv.Client())

	_, err := c.doGet(context.Background(), srv.URL+"/test")
	if err == nil {
		t.Fatal("expected error for 404")
	}
	if attempts != 1 {
		t.Errorf("expected 1 attempt (no retry on 404), got %d", attempts)
	}
}

func TestDoRequest_401NoRetry(t *testing.T) {
	attempts := 0
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		attempts++
		w.WriteHeader(401)
		w.Write([]byte(`{"message":"bad credentials"}`))
	}))
	defer srv.Close()

	c := NewClient("token", srv.URL, AllowInsecureHTTP())
	c.SetHTTPClient(srv.Client())

	_, err := c.doGet(context.Background(), srv.URL+"/test")
	if err == nil {
		t.Fatal("expected error for 401")
	}
	if attempts != 1 {
		t.Errorf("expected 1 attempt (no retry on 401), got %d", attempts)
	}
}

func TestIsNotFound(t *testing.T) {
	err := &APIError{StatusCode: 404, Body: "not found"}
	if !IsNotFound(err) {
		t.Error("expected IsNotFound to return true for 404")
	}
	err2 := &APIError{StatusCode: 500, Body: "server error"}
	if IsNotFound(err2) {
		t.Error("expected IsNotFound to return false for 500")
	}
}

func TestIsUnauthorized(t *testing.T) {
	err := &APIError{StatusCode: 401, Body: "bad credentials"}
	if !IsUnauthorized(err) {
		t.Error("expected IsUnauthorized to return true for 401")
	}
}

func TestAPIError_SanitizesNewlines(t *testing.T) {
	err := &APIError{StatusCode: 500, Body: "line1\ninjected\rmore"}
	msg := err.Error()
	if strings.Contains(msg, "\n") || strings.Contains(msg, "\r") {
		t.Errorf("expected newlines to be sanitized, got: %q", msg)
	}
	if !strings.Contains(msg, "line1 injected more") {
		t.Errorf("expected sanitized body, got: %q", msg)
	}
}

func TestDoRequest_429RetryAfterHeader(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping slow retry test in short mode")
	}
	attempts := 0
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		attempts++
		if attempts == 1 {
			w.Header().Set("Retry-After", "1")
			w.WriteHeader(429)
			w.Write([]byte(`{"message":"rate limit"}`))
			return
		}
		w.WriteHeader(200)
		w.Write([]byte(`{"ok":true}`))
	}))
	defer srv.Close()

	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)
	}

	start := time.Now()
	body, err := c.doGet(context.Background(), srv.URL+"/test")
	elapsed := time.Since(start)

	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if string(body) != `{"ok":true}` {
		t.Errorf("unexpected body: %s", body)
	}
	if attempts != 2 {
		t.Errorf("expected 2 attempts, got %d", attempts)
	}
	// Retry-After: 1 means at least 1 second delay
	if elapsed < 900*time.Millisecond {
		t.Errorf("expected ~1s delay from Retry-After, got %v", elapsed)
	}
}

func TestDoRequest_RetryAfterDoesNotMutateBackoff(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping slow retry test in short mode")
	}
	attempts := 0
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		attempts++
		if attempts == 1 {
			w.Header().Set("Retry-After", "1")
			w.WriteHeader(429)
			w.Write([]byte(`{"message":"rate limit"}`))
			return
		}
		w.WriteHeader(200)
		w.Write([]byte(`{"ok":true}`))
	}))
	defer srv.Close()

	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)
	}

	_, err := c.doGet(context.Background(), srv.URL+"/test")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	// Verify the original retryBackoff slice was not mutated
	if c.retryBackoff[0] != 1*time.Millisecond {
		t.Errorf("retryBackoff[0] was mutated: got %v, want 1ms", c.retryBackoff[0])
	}
	if c.retryBackoff[1] != 1*time.Millisecond {
		t.Errorf("retryBackoff[1] was mutated: got %v, want 1ms", c.retryBackoff[1])
	}
}

func TestDoRequest_429RetryAfterHTTPDate(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping slow Retry-After HTTP-date test in short mode")
	}
	attempts := 0
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		attempts++
		if attempts == 1 {
			// Use HTTP-date format (RFC 7231) — a time 2 seconds in the future.
			future := time.Now().Add(2 * time.Second).UTC()
			w.Header().Set("Retry-After", future.Format(http.TimeFormat))
			w.WriteHeader(429)
			w.Write([]byte(`{"message":"rate limit"}`))
			return
		}
		w.WriteHeader(200)
		w.Write([]byte(`{"ok":true}`))
	}))
	defer srv.Close()

	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)
	}

	start := time.Now()
	body, err := c.doGet(context.Background(), srv.URL+"/test")
	elapsed := time.Since(start)

	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if string(body) != `{"ok":true}` {
		t.Errorf("unexpected body: %s", body)
	}
	if attempts != 2 {
		t.Errorf("expected 2 attempts, got %d", attempts)
	}
	// HTTP-date was ~2s in the future; by the time client processes it,
	// time.Until gives ~1-2s. Verify it's meaningfully delayed (not instant).
	if elapsed < 500*time.Millisecond {
		t.Errorf("expected meaningful delay from HTTP-date Retry-After, got %v", elapsed)
	}
}

func TestDoRequest_429RetryAfterHTTPDateInPast(t *testing.T) {
	attempts := 0
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		attempts++
		if attempts == 1 {
			// Use a time in the past — should result in zero/immediate retry.
			past := time.Now().Add(-10 * time.Second).UTC()
			w.Header().Set("Retry-After", past.Format(http.TimeFormat))
			w.WriteHeader(429)
			w.Write([]byte(`{"message":"rate limit"}`))
			return
		}
		w.WriteHeader(200)
		w.Write([]byte(`{"ok":true}`))
	}))
	defer srv.Close()

	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)
	}

	start := time.Now()
	_, err := c.doGet(context.Background(), srv.URL+"/test")
	elapsed := time.Since(start)

	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if attempts != 2 {
		t.Errorf("expected 2 attempts, got %d", attempts)
	}
	// Past date should override the 5s backoff to ~0
	if elapsed > 500*time.Millisecond {
		t.Errorf("expected near-instant retry for past HTTP-date, got %v", elapsed)
	}
}

func TestDoRequest_SetsUserAgentHeader(t *testing.T) {
	var gotUA string
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		gotUA = r.Header.Get("User-Agent")
		w.WriteHeader(200)
		w.Write([]byte("{}"))
	}))
	defer srv.Close()

	c := NewClient("token", srv.URL, AllowInsecureHTTP())
	c.SetHTTPClient(srv.Client())
	_, _ = c.doGet(context.Background(), srv.URL+"/test")

	if gotUA != "review-bot/1.0" {
		t.Errorf("expected User-Agent 'review-bot/1.0', got %q", gotUA)
	}
}

func TestDoRequest_LimitsResponseBody(t *testing.T) {
	// Verify that oversized responses return an error rather than silently truncating.
	bigBody := strings.Repeat("x", maxResponseBytes+1024)
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(200)
		w.Write([]byte(bigBody))
	}))
	defer srv.Close()

	c := NewClient("token", srv.URL, AllowInsecureHTTP())
	c.SetHTTPClient(srv.Client())
	_, err := c.doGet(context.Background(), srv.URL+"/test")
	if err == nil {
		t.Fatal("expected error for oversized response body")
	}
	if !strings.Contains(err.Error(), "exceeded") {
		t.Errorf("expected truncation error, got: %v", err)
	}
}

func TestDoRequest_AcceptsExactlyAtLimit(t *testing.T) {
	// A response body exactly equal to maxResponseBytes should succeed (not error).
	exactBody := strings.Repeat("x", maxResponseBytes)
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(200)
		w.Write([]byte(exactBody))
	}))
	defer srv.Close()

	c := NewClient("token", srv.URL, AllowInsecureHTTP())
	c.SetHTTPClient(srv.Client())
	body, err := c.doGet(context.Background(), srv.URL+"/test")
	if err != nil {
		t.Fatalf("unexpected error for exactly-at-limit body: %v", err)
	}
	if len(body) != maxResponseBytes {
		t.Errorf("expected body length %d, got %d", maxResponseBytes, len(body))
	}
}

func TestDoRequest_SkipsAuthWhenTokenEmpty(t *testing.T) {
	var gotAuth string
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		gotAuth = r.Header.Get("Authorization")
		w.WriteHeader(200)
		w.Write([]byte("{}"))
	}))
	defer srv.Close()

	c := NewClient("", srv.URL, AllowInsecureHTTP()) // empty token
	c.SetHTTPClient(srv.Client())
	_, _ = c.doGet(context.Background(), srv.URL+"/test")

	if gotAuth != "" {
		t.Errorf("expected no Authorization header with empty token, got %q", gotAuth)
	}
}

func TestNewClient_CheckRedirectStripsAuthOnCrossHost(t *testing.T) {
	// Verify the CheckRedirect function is configured
	c := NewClient("secret-token", "https://api.github.com")
	if c.httpClient.CheckRedirect == nil {
		t.Fatal("expected CheckRedirect to be set")
	}
}

func TestDefaultCheckRedirect_RejectsHTTPSToHTTP(t *testing.T) {
	prev := &http.Request{URL: &url.URL{Scheme: "https", Host: "api.github.com", Path: "/foo"}}
	req := &http.Request{
		URL:    &url.URL{Scheme: "http", Host: "api.github.com", Path: "/foo"},
		Header: http.Header{"Authorization": []string{"Bearer token"}},
	}
	err := defaultCheckRedirect(req, []*http.Request{prev})
	if err == nil {
		t.Fatal("expected error on HTTPS→HTTP redirect")
	}
	if !strings.Contains(err.Error(), "refusing redirect from HTTPS to HTTP") {
		t.Errorf("unexpected error message: %v", err)
	}
}

func TestDefaultCheckRedirect_StripsAuthOnCrossHost(t *testing.T) {
	prev := &http.Request{URL: &url.URL{Scheme: "https", Host: "api.github.com", Path: "/foo"}}
	req := &http.Request{
		URL:    &url.URL{Scheme: "https", Host: "objects.githubusercontent.com", Path: "/bar"},
		Header: http.Header{"Authorization": []string{"Bearer token"}},
	}
	err := defaultCheckRedirect(req, []*http.Request{prev})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if auth := req.Header.Get("Authorization"); auth != "" {
		t.Errorf("expected Authorization header to be stripped, got %q", auth)
	}
}

func TestDefaultCheckRedirect_PreservesAuthOnSameHost(t *testing.T) {
	prev := &http.Request{URL: &url.URL{Scheme: "https", Host: "api.github.com", Path: "/foo"}}
	req := &http.Request{
		URL:    &url.URL{Scheme: "https", Host: "api.github.com", Path: "/bar"},
		Header: http.Header{"Authorization": []string{"Bearer token"}},
	}
	err := defaultCheckRedirect(req, []*http.Request{prev})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if auth := req.Header.Get("Authorization"); auth != "Bearer token" {
		t.Errorf("expected Authorization to be preserved, got %q", auth)
	}
}

func TestDoRequest_RejectsHTTPWithToken(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(200)
		w.Write([]byte("{}"))
	}))
	defer srv.Close()

	// Without AllowInsecureHTTP, should refuse to send token over HTTP
	c := NewClient("secret-token", srv.URL)
	c.SetHTTPClient(srv.Client())
	_, err := c.doGet(context.Background(), srv.URL+"/test")
	if err == nil {
		t.Fatal("expected error when sending token over HTTP")
	}
	if !strings.Contains(err.Error(), "refusing to send credentials") {
		t.Errorf("unexpected error message: %v", err)
	}
}

func TestDoRequest_AllowsHTTPWithoutToken(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(200)
		w.Write([]byte(`{"ok":true}`))
	}))
	defer srv.Close()

	// Without token, HTTP should be fine (no credentials to leak)
	c := NewClient("", srv.URL)
	c.SetHTTPClient(srv.Client())
	body, err := c.doGet(context.Background(), srv.URL+"/test")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if string(body) != `{"ok":true}` {
		t.Errorf("unexpected body: %s", body)
	}
}

func TestDoRequest_AllowsHTTPWithInsecureOption(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(200)
		w.Write([]byte(`{"ok":true}`))
	}))
	defer srv.Close()

	c := NewClient("secret-token", srv.URL, AllowInsecureHTTP())
	c.SetHTTPClient(srv.Client())
	body, err := c.doGet(context.Background(), srv.URL+"/test")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if string(body) != `{"ok":true}` {
		t.Errorf("unexpected body: %s", body)
	}
}

func TestSetHTTPClient_NilRestoresDefault(t *testing.T) {
	c := NewClient("token", "https://api.github.com")
	c.SetHTTPClient(nil)
	if c.httpClient == nil {
		t.Fatal("expected non-nil httpClient after SetHTTPClient(nil)")
	}
	if c.httpClient.Timeout != 30*time.Second {
		t.Errorf("expected 30s timeout, got %v", c.httpClient.Timeout)
	}
	if c.httpClient.CheckRedirect == nil {
		t.Fatal("expected CheckRedirect policy after SetHTTPClient(nil)")
	}
}

func TestSetRetryBackoff_RejectsInvalidLength(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")
	}
	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)
	}
}

func TestDoJSONRequest_429Retry(t *testing.T) {
	attempts := 0
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		attempts++
		if attempts < 3 {
			w.WriteHeader(429)
			w.Write([]byte(`{"message":"rate limit exceeded"}`))
			return
		}
		w.WriteHeader(200)
		w.Write([]byte(`{"id":1}`))
	}))
	defer ts.Close()

	c := NewClient("token", ts.URL, AllowInsecureHTTP())
	if err := c.SetRetryBackoff([]time.Duration{1 * time.Millisecond, 1 * time.Millisecond}); err != nil {
		t.Fatalf("SetRetryBackoff: %v", err)
	}

	body, err := c.doJSONRequest(context.Background(), http.MethodPost, ts.URL+"/test", map[string]string{"key": "val"})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if attempts != 3 {
		t.Errorf("expected 3 attempts, got %d", attempts)
	}
	if string(body) != `{"id":1}` {
		t.Errorf("unexpected body: %s", body)
	}
}

func TestDoJSONRequest_429ExhaustsRetries(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(429)
		w.Write([]byte(`{"message":"rate limit"}`))
	}))
	defer ts.Close()

	c := NewClient("token", ts.URL, AllowInsecureHTTP())
	if err := c.SetRetryBackoff([]time.Duration{1 * time.Millisecond, 1 * time.Millisecond}); err != nil {
		t.Fatalf("SetRetryBackoff: %v", err)
	}

	_, err := c.doJSONRequest(context.Background(), http.MethodPost, ts.URL+"/test", map[string]string{"key": "val"})
	if err == nil {
		t.Fatal("expected error after exhausting retries")
	}
	var apiErr *APIError
	if !errors.As(err, &apiErr) {
		t.Fatalf("expected APIError, got %T: %v", err, err)
	}
	if apiErr.StatusCode != 429 {
		t.Errorf("expected 429, got %d", apiErr.StatusCode)
	}
}