test(#139): improve cmd/review-bot coverage from 44.6% to 49.3% (#140)

cmd/review-bot/validateurl_test.go

@@ -125,3 +125,60 @@ func TestRunValidateURL_WithCapture(t *testing.T) {
 		t.Errorf("expected error about https in stderr, got %q", errBuf.String())
 	}
 }
+
+// TestIsValidateError_Nil confirms that isValidateError returns false for a nil error.
+func TestIsValidateError_Nil(t *testing.T) {
+	var ve *validateError
+	if isValidateError(nil, &ve) {
+		t.Error("isValidateError(nil, ...) should return false")
+	}
+}
+
+// TestValidateURL_EmptyHost confirms that a URL with no hostname returns a code-2 error.
+func TestValidateURL_EmptyHost(t *testing.T) {
+	// "https://" parses fine but has no hostname.
+	err := validateURL("https://")
+	if err == nil {
+		t.Fatal("expected error for URL with no host, got nil")
+	}
+	var ve *validateError
+	if !isValidateError(err, &ve) {
+		t.Fatalf("expected *validateError, got %T: %v", err, err)
+	}
+	if ve.code != 2 {
+		t.Errorf("expected code 2, got %d (msg=%s)", ve.code, ve.message)
+	}
+	if !strings.Contains(ve.message, "no host") {
+		t.Errorf("expected 'no host' in error message, got %q", ve.message)
+	}
+}
+
+// TestRunValidateURL_Success confirms that a resolvable public URL prints "OK" and returns 0.
+// This test requires external DNS; it is skipped in environments without network access.
+func TestRunValidateURL_Success(t *testing.T) {
+	// Pre-check: validate that DNS is available before exercising the success path.
+	err := validateURL("https://example.com/")
+	if err != nil {
+		t.Skipf("skipping success-path test: DNS unavailable or example.com blocked (%v)", err)
+	}
+
+	var outBuf, errBuf bytes.Buffer
+	origOut, origErr := outWriter, errWriter
+	outWriter = &outBuf
+	errWriter = &errBuf
+	defer func() {
+		outWriter = origOut
+		errWriter = origErr
+	}()
+
+	code := runValidateURL([]string{"https://example.com/"})
+	if code != 0 {
+		t.Errorf("expected exit code 0 for safe URL, got %d (stderr: %s)", code, errBuf.String())
+	}
+	if !strings.Contains(outBuf.String(), "OK:") {
+		t.Errorf("expected 'OK:' in stdout, got %q", outBuf.String())
+	}
+	if errBuf.Len() != 0 {
+		t.Errorf("expected no stderr for safe URL, got %q", errBuf.String())
+	}
+}