Initial commit
diff --git a/claudetool/differential.go b/claudetool/differential.go
new file mode 100644
index 0000000..14dce04
--- /dev/null
+++ b/claudetool/differential.go
@@ -0,0 +1,1125 @@
+package claudetool
+
+import (
+ "bytes"
+ "context"
+ "encoding/json"
+ "fmt"
+ "io"
+ "log/slog"
+ "maps"
+ "os"
+ "os/exec"
+ "path/filepath"
+ "slices"
+ "strings"
+ "time"
+
+ "golang.org/x/tools/go/packages"
+ "sketch.dev/ant"
+)
+
+// This file does differential quality analysis of a commit relative to a base commit.
+
+// Tool returns a tool spec for a CodeReview tool backed by r.
+func (r *CodeReviewer) Tool() *ant.Tool {
+ spec := &ant.Tool{
+ Name: "codereview",
+ Description: `Run an automated code review.`,
+ // If you modify this, update the termui template for prettier rendering.
+ InputSchema: ant.MustSchema(`{"type": "object"}`),
+ Run: r.Run,
+ }
+ return spec
+}
+
+func (r *CodeReviewer) Run(ctx context.Context, m json.RawMessage) (string, error) {
+ if err := r.RequireNormalGitState(ctx); err != nil {
+ slog.DebugContext(ctx, "CodeReviewer.Run: failed to check for normal git state", "err", err)
+ return "", err
+ }
+ if err := r.RequireNoUncommittedChanges(ctx); err != nil {
+ slog.DebugContext(ctx, "CodeReviewer.Run: failed to check for uncommitted changes", "err", err)
+ return "", err
+ }
+
+ // Check that the current commit is not the initial commit
+ currentCommit, err := r.CurrentCommit(ctx)
+ if err != nil {
+ slog.DebugContext(ctx, "CodeReviewer.Run: failed to get current commit", "err", err)
+ return "", err
+ }
+ if r.IsInitialCommit(currentCommit) {
+ slog.DebugContext(ctx, "CodeReviewer.Run: current commit is initial commit, nothing to review")
+ return "", fmt.Errorf("no new commits have been added, nothing to review")
+ }
+
+ // No matter what failures happen from here out, we will declare this to have been reviewed.
+ // This should help avoid the model getting blocked by a broken code review tool.
+ r.reviewed = append(r.reviewed, currentCommit)
+
+ changedFiles, err := r.changedFiles(ctx, r.initialCommit, currentCommit)
+ if err != nil {
+ slog.DebugContext(ctx, "CodeReviewer.Run: failed to get changed files", "err", err)
+ return "", err
+ }
+
+ // Prepare to analyze before/after for the impacted files.
+ // We use the current commit to determine what packages exist and are impacted.
+ // The packages in the initial commit may be different.
+ // Good enough for now.
+ // TODO: do better
+ directPkgs, allPkgs, err := r.packagesForFiles(ctx, changedFiles)
+ if err != nil {
+ // TODO: log and skip to stuff that doesn't require packages
+ slog.DebugContext(ctx, "CodeReviewer.Run: failed to get packages for files", "err", err)
+ return "", err
+ }
+ allPkgList := slices.Collect(maps.Keys(allPkgs))
+ directPkgList := slices.Collect(maps.Keys(directPkgs))
+
+ var msgs []string
+
+ testMsg, err := r.checkTests(ctx, allPkgList)
+ if err != nil {
+ slog.DebugContext(ctx, "CodeReviewer.Run: failed to check tests", "err", err)
+ return "", err
+ }
+ if testMsg != "" {
+ msgs = append(msgs, testMsg)
+ }
+
+ vetMsg, err := r.checkVet(ctx, directPkgList)
+ if err != nil {
+ slog.DebugContext(ctx, "CodeReviewer.Run: failed to check vet", "err", err)
+ return "", err
+ }
+ if vetMsg != "" {
+ msgs = append(msgs, vetMsg)
+ }
+
+ goplsMsg, err := r.checkGopls(ctx, changedFiles)
+ if err != nil {
+ slog.DebugContext(ctx, "CodeReviewer.Run: failed to check gopls", "err", err)
+ return "", err
+ }
+ if goplsMsg != "" {
+ msgs = append(msgs, goplsMsg)
+ }
+
+ if len(msgs) == 0 {
+ slog.DebugContext(ctx, "CodeReviewer.Run: no issues found")
+ return "OK", nil
+ }
+ slog.DebugContext(ctx, "CodeReviewer.Run: found issues", "issues", msgs)
+ return strings.Join(msgs, "\n\n"), nil
+}
+
+func (r *CodeReviewer) initializeInitialCommitWorktree(ctx context.Context) error {
+ if r.initialWorktree != "" {
+ return nil
+ }
+ tmpDir, err := os.MkdirTemp("", "sketch-codereview-worktree")
+ if err != nil {
+ return err
+ }
+ worktreeCmd := exec.CommandContext(ctx, "git", "worktree", "add", "--detach", tmpDir, r.initialCommit)
+ worktreeCmd.Dir = r.repoRoot
+ out, err := worktreeCmd.CombinedOutput()
+ if err != nil {
+ return fmt.Errorf("unable to create worktree for initial commit: %w\n%s", err, out)
+ }
+ r.initialWorktree = tmpDir
+ return nil
+}
+
+func (r *CodeReviewer) checkTests(ctx context.Context, pkgList []string) (string, error) {
+ goTestArgs := []string{"test", "-json", "-v"}
+ goTestArgs = append(goTestArgs, pkgList...)
+
+ afterTestCmd := exec.CommandContext(ctx, "go", goTestArgs...)
+ afterTestCmd.Dir = r.repoRoot
+ afterTestOut, afterTestErr := afterTestCmd.Output()
+ if afterTestErr == nil {
+ return "", nil // all tests pass, we're good!
+ }
+
+ err := r.initializeInitialCommitWorktree(ctx)
+ if err != nil {
+ return "", err
+ }
+
+ beforeTestCmd := exec.CommandContext(ctx, "go", goTestArgs...)
+ beforeTestCmd.Dir = r.initialWorktree
+ beforeTestOut, _ := beforeTestCmd.Output() // ignore error, interesting info is in the output
+
+ // Parse the jsonl test results
+ beforeResults, beforeParseErr := parseTestResults(beforeTestOut)
+ if beforeParseErr != nil {
+ return "", fmt.Errorf("unable to parse test results for initial commit: %w\n%s", beforeParseErr, beforeTestOut)
+ }
+ afterResults, afterParseErr := parseTestResults(afterTestOut)
+ if afterParseErr != nil {
+ return "", fmt.Errorf("unable to parse test results for current commit: %w\n%s", afterParseErr, afterTestOut)
+ }
+
+ testRegressions, err := r.compareTestResults(beforeResults, afterResults)
+ if err != nil {
+ return "", fmt.Errorf("failed to compare test results: %w", err)
+ }
+ // TODO: better output formatting?
+ res := r.formatTestRegressions(testRegressions)
+ return res, nil
+}
+
+// VetIssue represents a single issue found by go vet
+type VetIssue struct {
+ Position string `json:"posn"`
+ Message string `json:"message"`
+ // Ignoring suggested_fixes for now as we don't need them for comparison
+}
+
+// VetResult represents the JSON output of go vet -json for a single package
+type VetResult map[string][]VetIssue // category -> issues
+
+// VetResults represents the full JSON output of go vet -json
+type VetResults map[string]VetResult // package path -> result
+
+// checkVet runs go vet on the provided packages in both the current and initial state,
+// compares the results, and reports any new vet issues introduced in the current state.
+func (r *CodeReviewer) checkVet(ctx context.Context, pkgList []string) (string, error) {
+ if len(pkgList) == 0 {
+ return "", nil // no packages to check
+ }
+
+ // Run vet on the current state with JSON output
+ goVetArgs := []string{"vet", "-json"}
+ goVetArgs = append(goVetArgs, pkgList...)
+
+ afterVetCmd := exec.CommandContext(ctx, "go", goVetArgs...)
+ afterVetCmd.Dir = r.repoRoot
+ afterVetOut, afterVetErr := afterVetCmd.CombinedOutput() // ignore error, we'll parse the output regar
+ if afterVetErr != nil {
+ slog.WarnContext(ctx, "CodeReviewer.checkVet: (after) go vet failed", "err", afterVetErr, "output", string(afterVetOut))
+ return "", nil // nothing more we can do here
+ }
+
+ // Parse the JSON output (even if vet returned an error, as it does when issues are found)
+ afterVetResults, err := parseVetJSON(afterVetOut)
+ if err != nil {
+ return "", fmt.Errorf("failed to parse vet output for current state: %w", err)
+ }
+
+ // If no issues were found, we're done
+ if len(afterVetResults) == 0 || !vetResultsHaveIssues(afterVetResults) {
+ return "", nil
+ }
+
+ // Vet detected issues in the current state, check if they existed in the initial state
+ err = r.initializeInitialCommitWorktree(ctx)
+ if err != nil {
+ return "", err
+ }
+
+ beforeVetCmd := exec.CommandContext(ctx, "go", goVetArgs...)
+ beforeVetCmd.Dir = r.initialWorktree
+ beforeVetOut, _ := beforeVetCmd.CombinedOutput() // ignore error, we'll parse the output anyway
+
+ // Parse the JSON output for the initial state
+ beforeVetResults, err := parseVetJSON(beforeVetOut)
+ if err != nil {
+ return "", fmt.Errorf("failed to parse vet output for initial state: %w", err)
+ }
+
+ // Find new issues that weren't present in the initial state
+ vetRegressions := findVetRegressions(beforeVetResults, afterVetResults)
+ if !vetResultsHaveIssues(vetRegressions) {
+ return "", nil // no new issues
+ }
+
+ // Format the results
+ return formatVetRegressions(vetRegressions), nil
+}
+
+// parseVetJSON parses the JSON output from go vet -json
+func parseVetJSON(output []byte) (VetResults, error) {
+ // The output contains multiple JSON objects, one per package
+ // We need to parse them separately
+ results := make(VetResults)
+
+ // Process the output by collecting JSON chunks between # comment lines
+ lines := strings.Split(string(output), "\n")
+ currentChunk := strings.Builder{}
+
+ // Helper function to process accumulated JSON chunks
+ processChunk := func() {
+ chunk := strings.TrimSpace(currentChunk.String())
+ if chunk == "" || !strings.HasPrefix(chunk, "{") {
+ return // Skip empty chunks or non-JSON chunks
+ }
+
+ // Try to parse the chunk as JSON
+ var result VetResults
+ if err := json.Unmarshal([]byte(chunk), &result); err != nil {
+ return // Skip invalid JSON
+ }
+
+ // Merge with our results
+ for pkg, issues := range result {
+ results[pkg] = issues
+ }
+
+ // Reset the chunk builder
+ currentChunk.Reset()
+ }
+
+ // Process lines
+ for _, line := range lines {
+ // If we hit a comment line, process the previous chunk and start a new one
+ if strings.HasPrefix(strings.TrimSpace(line), "#") {
+ processChunk()
+ continue
+ }
+
+ // Add the line to the current chunk
+ currentChunk.WriteString(line)
+ currentChunk.WriteString("\n")
+ }
+
+ // Process the final chunk
+ processChunk()
+
+ return results, nil
+}
+
+// vetResultsHaveIssues checks if there are any actual issues in the vet results
+func vetResultsHaveIssues(results VetResults) bool {
+ for _, pkgResult := range results {
+ for _, issues := range pkgResult {
+ if len(issues) > 0 {
+ return true
+ }
+ }
+ }
+ return false
+}
+
+// findVetRegressions identifies vet issues that are new in the after state
+func findVetRegressions(before, after VetResults) VetResults {
+ regressions := make(VetResults)
+
+ // Go through all packages in the after state
+ for pkgPath, afterPkgResults := range after {
+ beforePkgResults, pkgExistedBefore := before[pkgPath]
+
+ // Initialize package in regressions if it has issues
+ if !pkgExistedBefore {
+ // If the package didn't exist before, all issues are new
+ regressions[pkgPath] = afterPkgResults
+ continue
+ }
+
+ // Compare issues by category
+ for category, afterIssues := range afterPkgResults {
+ beforeIssues, categoryExistedBefore := beforePkgResults[category]
+
+ if !categoryExistedBefore {
+ // If this category didn't exist before, all issues are new
+ if regressions[pkgPath] == nil {
+ regressions[pkgPath] = make(VetResult)
+ }
+ regressions[pkgPath][category] = afterIssues
+ continue
+ }
+
+ // Compare individual issues
+ var newIssues []VetIssue
+ for _, afterIssue := range afterIssues {
+ if !issueExistsIn(afterIssue, beforeIssues) {
+ newIssues = append(newIssues, afterIssue)
+ }
+ }
+
+ // Add new issues to regressions
+ if len(newIssues) > 0 {
+ if regressions[pkgPath] == nil {
+ regressions[pkgPath] = make(VetResult)
+ }
+ regressions[pkgPath][category] = newIssues
+ }
+ }
+ }
+
+ return regressions
+}
+
+// issueExistsIn checks if an issue already exists in a list of issues
+// using a looser comparison that's resilient to position changes
+func issueExistsIn(issue VetIssue, issues []VetIssue) bool {
+ issueFile := extractFilePath(issue.Position)
+
+ for _, existing := range issues {
+ // Main comparison is by message content, which is likely stable
+ if issue.Message == existing.Message {
+ // If messages match exactly, consider it the same issue even if position changed
+ return true
+ }
+
+ // As a secondary check, if the issue is in the same file and has similar message,
+ // it's likely the same issue that might have been slightly reworded or relocated
+ existingFile := extractFilePath(existing.Position)
+ if issueFile == existingFile && messagesSimilar(issue.Message, existing.Message) {
+ return true
+ }
+ }
+ return false
+}
+
+// extractFilePath gets just the file path from a position string like "/path/to/file.go:10:15"
+func extractFilePath(position string) string {
+ parts := strings.Split(position, ":")
+ if len(parts) >= 1 {
+ return parts[0]
+ }
+ return position // fallback to the full position if we can't parse it
+}
+
+// messagesSimilar checks if two messages are similar enough to be considered the same issue
+// This is a simple implementation that could be enhanced with more sophisticated text comparison
+func messagesSimilar(msg1, msg2 string) bool {
+ // For now, simple similarity check: if one is a substring of the other
+ return strings.Contains(msg1, msg2) || strings.Contains(msg2, msg1)
+}
+
+// formatVetRegressions generates a human-readable summary of vet regressions
+func formatVetRegressions(regressions VetResults) string {
+ if !vetResultsHaveIssues(regressions) {
+ return ""
+ }
+
+ var sb strings.Builder
+ sb.WriteString("Go vet issues detected:\n\n")
+
+ // Get sorted list of packages for deterministic output
+ pkgPaths := make([]string, 0, len(regressions))
+ for pkgPath := range regressions {
+ pkgPaths = append(pkgPaths, pkgPath)
+ }
+ slices.Sort(pkgPaths)
+
+ issueCount := 1
+ for _, pkgPath := range pkgPaths {
+ pkgResult := regressions[pkgPath]
+
+ // Get sorted list of categories
+ categories := make([]string, 0, len(pkgResult))
+ for category := range pkgResult {
+ categories = append(categories, category)
+ }
+ slices.Sort(categories)
+
+ for _, category := range categories {
+ issues := pkgResult[category]
+
+ // Skip empty issue lists (shouldn't happen, but just in case)
+ if len(issues) == 0 {
+ continue
+ }
+
+ // Sort issues by position for deterministic output
+ slices.SortFunc(issues, func(a, b VetIssue) int {
+ return strings.Compare(a.Position, b.Position)
+ })
+
+ // Format each issue
+ for _, issue := range issues {
+ sb.WriteString(fmt.Sprintf("%d. [%s] %s: %s\n",
+ issueCount,
+ category,
+ issue.Position,
+ issue.Message))
+ issueCount++
+ }
+ }
+ }
+
+ sb.WriteString("\nPlease fix these issues before proceeding.")
+ return sb.String()
+}
+
+// GoplsIssue represents a single issue reported by gopls check
+type GoplsIssue struct {
+ Position string // File position in format "file:line:col-range"
+ Message string // Description of the issue
+}
+
+// checkGopls runs gopls check on the provided files in both the current and initial state,
+// compares the results, and reports any new issues introduced in the current state.
+func (r *CodeReviewer) checkGopls(ctx context.Context, changedFiles []string) (string, error) {
+ if len(changedFiles) == 0 {
+ return "", nil // no files to check
+ }
+
+ // Filter out non-Go files as gopls only works on Go files
+ // and verify they still exist (not deleted)
+ var goFiles []string
+ for _, file := range changedFiles {
+ if !strings.HasSuffix(file, ".go") {
+ continue // not a Go file
+ }
+
+ // Check if the file still exists (not deleted)
+ if _, err := os.Stat(file); os.IsNotExist(err) {
+ continue // file doesn't exist anymore (deleted)
+ }
+
+ goFiles = append(goFiles, file)
+ }
+
+ if len(goFiles) == 0 {
+ return "", nil // no Go files to check
+ }
+
+ // Run gopls check on the current state
+ goplsArgs := append([]string{"check"}, goFiles...)
+
+ afterGoplsCmd := exec.CommandContext(ctx, "gopls", goplsArgs...)
+ afterGoplsCmd.Dir = r.repoRoot
+ afterGoplsOut, err := afterGoplsCmd.CombinedOutput() // gopls returns non-zero if it finds issues
+ if err != nil {
+ // Check if the output looks like real gopls issues or if it's just error output
+ if !looksLikeGoplsIssues(afterGoplsOut) {
+ slog.WarnContext(ctx, "CodeReviewer.checkGopls: gopls check failed to run properly", "err", err, "output", string(afterGoplsOut))
+ return "", nil // Skip rather than failing the entire code review
+ }
+ // Otherwise, proceed with parsing - it's likely just the non-zero exit code due to found issues
+ }
+
+ // Parse the output
+ afterIssues := parseGoplsOutput(afterGoplsOut)
+
+ // If no issues were found, we're done
+ if len(afterIssues) == 0 {
+ return "", nil
+ }
+
+ // Gopls detected issues in the current state, check if they existed in the initial state
+ initErr := r.initializeInitialCommitWorktree(ctx)
+ if initErr != nil {
+ return "", err
+ }
+
+ // For each file that exists in the initial commit, run gopls check
+ var initialFilesToCheck []string
+ for _, file := range goFiles {
+ // Get relative path for git operations
+ relFile, err := filepath.Rel(r.repoRoot, file)
+ if err != nil {
+ slog.WarnContext(ctx, "CodeReviewer.checkGopls: failed to get relative path", "repo_root", r.repoRoot, "file", file, "err", err)
+ continue
+ }
+
+ // Check if the file exists in the initial commit
+ checkCmd := exec.CommandContext(ctx, "git", "cat-file", "-e", fmt.Sprintf("%s:%s", r.initialCommit, relFile))
+ checkCmd.Dir = r.repoRoot
+ if err := checkCmd.Run(); err == nil {
+ // File exists in initial commit
+ initialFilePath := filepath.Join(r.initialWorktree, relFile)
+ initialFilesToCheck = append(initialFilesToCheck, initialFilePath)
+ }
+ }
+
+ // Run gopls check on the files that existed in the initial commit
+ beforeIssues := []GoplsIssue{}
+ if len(initialFilesToCheck) > 0 {
+ beforeGoplsArgs := append([]string{"check"}, initialFilesToCheck...)
+ beforeGoplsCmd := exec.CommandContext(ctx, "gopls", beforeGoplsArgs...)
+ beforeGoplsCmd.Dir = r.initialWorktree
+ var beforeGoplsOut []byte
+ var beforeCmdErr error
+ beforeGoplsOut, beforeCmdErr = beforeGoplsCmd.CombinedOutput()
+ if beforeCmdErr != nil && !looksLikeGoplsIssues(beforeGoplsOut) {
+ // If gopls fails to run properly on the initial commit, log a warning and continue
+ // with empty before issues - this will be conservative and report more issues
+ slog.WarnContext(ctx, "CodeReviewer.checkGopls: gopls check failed on initial commit",
+ "err", err, "output", string(beforeGoplsOut))
+ // Continue with empty beforeIssues
+ } else {
+ beforeIssues = parseGoplsOutput(beforeGoplsOut)
+ }
+ }
+
+ // Find new issues that weren't present in the initial state
+ goplsRegressions := findGoplsRegressions(beforeIssues, afterIssues)
+ if len(goplsRegressions) == 0 {
+ return "", nil // no new issues
+ }
+
+ // Format the results
+ return formatGoplsRegressions(goplsRegressions), nil
+}
+
+// parseGoplsOutput parses the text output from gopls check
+// Each line has the format: '/path/to/file.go:448:22-26: unused parameter: path'
+func parseGoplsOutput(output []byte) []GoplsIssue {
+ var issues []GoplsIssue
+ lines := strings.Split(string(output), "\n")
+
+ for _, line := range lines {
+ line = strings.TrimSpace(line)
+ if line == "" {
+ continue
+ }
+
+ // Skip lines that look like error messages rather than gopls issues
+ if strings.HasPrefix(line, "Error:") ||
+ strings.HasPrefix(line, "Failed:") ||
+ strings.HasPrefix(line, "Warning:") ||
+ strings.HasPrefix(line, "gopls:") {
+ continue
+ }
+
+ // Find the first colon that separates the file path from the line number
+ firstColonIdx := strings.Index(line, ":")
+ if firstColonIdx < 0 {
+ continue // Invalid format
+ }
+
+ // Verify the part before the first colon looks like a file path
+ potentialPath := line[:firstColonIdx]
+ if !strings.HasSuffix(potentialPath, ".go") {
+ continue // Not a Go file path
+ }
+
+ // Find the position of the first message separator ': '
+ // This separates the position info from the message
+ messageStart := strings.Index(line, ": ")
+ if messageStart < 0 || messageStart <= firstColonIdx {
+ continue // Invalid format
+ }
+
+ // Extract position and message
+ position := line[:messageStart]
+ message := line[messageStart+2:] // Skip the ': ' separator
+
+ // Verify position has the expected format (at least 2 colons for line:col)
+ colonCount := strings.Count(position, ":")
+ if colonCount < 2 {
+ continue // Not enough position information
+ }
+
+ issues = append(issues, GoplsIssue{
+ Position: position,
+ Message: message,
+ })
+ }
+
+ return issues
+}
+
+// looksLikeGoplsIssues checks if the output appears to be actual gopls issues
+// rather than error messages about gopls itself failing
+func looksLikeGoplsIssues(output []byte) bool {
+ // If output is empty, it's not valid issues
+ if len(output) == 0 {
+ return false
+ }
+
+ // Check if output has at least one line that looks like a gopls issue
+ // A gopls issue looks like: '/path/to/file.go:123:45-67: message'
+ lines := strings.Split(string(output), "\n")
+ for _, line := range lines {
+ line = strings.TrimSpace(line)
+ if line == "" {
+ continue
+ }
+
+ // A gopls issue has at least two colons (file path, line number, column)
+ // and contains a colon followed by a space (separating position from message)
+ colonCount := strings.Count(line, ":")
+ hasSeparator := strings.Contains(line, ": ")
+
+ if colonCount >= 2 && hasSeparator {
+ // Check if it starts with a likely file path (ending in .go)
+ parts := strings.SplitN(line, ":", 2)
+ if strings.HasSuffix(parts[0], ".go") {
+ return true
+ }
+ }
+ }
+ return false
+}
+
+// normalizeGoplsPosition extracts just the file path from a position string
+func normalizeGoplsPosition(position string) string {
+ // Extract just the file path by taking everything before the first colon
+ parts := strings.Split(position, ":")
+ if len(parts) < 1 {
+ return position
+ }
+ return parts[0]
+}
+
+// findGoplsRegressions identifies gopls issues that are new in the after state
+func findGoplsRegressions(before, after []GoplsIssue) []GoplsIssue {
+ var regressions []GoplsIssue
+
+ // Build map of before issues for easier lookup
+ beforeIssueMap := make(map[string]map[string]bool) // file -> message -> exists
+ for _, issue := range before {
+ file := normalizeGoplsPosition(issue.Position)
+ if _, exists := beforeIssueMap[file]; !exists {
+ beforeIssueMap[file] = make(map[string]bool)
+ }
+ // Store both the exact message and the general issue type for fuzzy matching
+ beforeIssueMap[file][issue.Message] = true
+
+ // Extract the general issue type (everything before the first ':' in the message)
+ generalIssue := issue.Message
+ if colonIdx := strings.Index(issue.Message, ":"); colonIdx > 0 {
+ generalIssue = issue.Message[:colonIdx]
+ }
+ beforeIssueMap[file][generalIssue] = true
+ }
+
+ // Check each after issue to see if it's new
+ for _, afterIssue := range after {
+ file := normalizeGoplsPosition(afterIssue.Position)
+ isNew := true
+
+ if fileIssues, fileExists := beforeIssueMap[file]; fileExists {
+ // Check for exact message match
+ if fileIssues[afterIssue.Message] {
+ isNew = false
+ } else {
+ // Check for general issue type match
+ generalIssue := afterIssue.Message
+ if colonIdx := strings.Index(afterIssue.Message, ":"); colonIdx > 0 {
+ generalIssue = afterIssue.Message[:colonIdx]
+ }
+ if fileIssues[generalIssue] {
+ isNew = false
+ }
+ }
+ }
+
+ if isNew {
+ regressions = append(regressions, afterIssue)
+ }
+ }
+
+ // Sort regressions for deterministic output
+ slices.SortFunc(regressions, func(a, b GoplsIssue) int {
+ return strings.Compare(a.Position, b.Position)
+ })
+
+ return regressions
+}
+
+// formatGoplsRegressions generates a human-readable summary of gopls check regressions
+func formatGoplsRegressions(regressions []GoplsIssue) string {
+ if len(regressions) == 0 {
+ return ""
+ }
+
+ var sb strings.Builder
+ sb.WriteString("Gopls check issues detected:\n\n")
+
+ // Format each issue
+ for i, issue := range regressions {
+ sb.WriteString(fmt.Sprintf("%d. %s: %s\n", i+1, issue.Position, issue.Message))
+ }
+
+ sb.WriteString("\nIMPORTANT: Only fix new gopls check issues in parts of the code that you have already edited. ")
+ sb.WriteString("Do not change existing code that was not part of your current edits.")
+ return sb.String()
+}
+
+func (r *CodeReviewer) HasReviewed(commit string) bool {
+ return slices.Contains(r.reviewed, commit)
+}
+
+func (r *CodeReviewer) IsInitialCommit(commit string) bool {
+ return commit == r.initialCommit
+}
+
+// packagesForFiles returns maps of packages related to the given files:
+// 1. directPkgs: packages that directly contain the changed files
+// 2. allPkgs: all packages that might be affected, including downstream packages that depend on the direct packages
+// It may include false positives.
+// Files must be absolute paths!
+func (r *CodeReviewer) packagesForFiles(ctx context.Context, files []string) (directPkgs, allPkgs map[string]*packages.Package, err error) {
+ for _, f := range files {
+ if !filepath.IsAbs(f) {
+ return nil, nil, fmt.Errorf("path %q is not absolute", f)
+ }
+ }
+ cfg := &packages.Config{
+ Mode: packages.LoadImports | packages.NeedEmbedFiles,
+ Context: ctx,
+ // Logf: func(msg string, args ...any) {
+ // slog.DebugContext(ctx, "loading go packages", "msg", fmt.Sprintf(msg, args...))
+ // },
+ // TODO: in theory, go.mod might not be in the repo root, and there might be multiple go.mod files.
+ // We can cross that bridge when we get there.
+ Dir: r.repoRoot,
+ Tests: true,
+ }
+ universe, err := packages.Load(cfg, "./...")
+ if err != nil {
+ return nil, nil, err
+ }
+ // Identify packages that directly contain the changed files
+ directPkgs = make(map[string]*packages.Package) // import path -> package
+ for _, pkg := range universe {
+ // fmt.Println("pkg:", pkg.PkgPath)
+ pkgFiles := allFiles(pkg)
+ // fmt.Println("pkgFiles:", pkgFiles)
+ for _, file := range files {
+ if pkgFiles[file] {
+ // prefer test packages, as they contain strictly more files (right?)
+ prev := directPkgs[pkg.PkgPath]
+ if prev == nil || prev.ForTest == "" {
+ directPkgs[pkg.PkgPath] = pkg
+ }
+ }
+ }
+ }
+
+ // Create a copy of directPkgs to expand with dependencies
+ allPkgs = make(map[string]*packages.Package)
+ for k, v := range directPkgs {
+ allPkgs[k] = v
+ }
+
+ // Add packages that depend on the direct packages
+ addDependentPackages(universe, allPkgs)
+ return directPkgs, allPkgs, nil
+}
+
+// allFiles returns all files that might be referenced by the package.
+// It may contain false positives.
+func allFiles(p *packages.Package) map[string]bool {
+ files := make(map[string]bool)
+ add := [][]string{p.GoFiles, p.CompiledGoFiles, p.OtherFiles, p.EmbedFiles, p.IgnoredFiles}
+ for _, extra := range add {
+ for _, file := range extra {
+ files[file] = true
+ }
+ }
+ return files
+}
+
+// addDependentPackages adds to pkgs all packages from universe
+// that directly or indirectly depend on any package already in pkgs.
+func addDependentPackages(universe []*packages.Package, pkgs map[string]*packages.Package) {
+ for {
+ changed := false
+ for _, p := range universe {
+ if _, ok := pkgs[p.PkgPath]; ok {
+ // already in pkgs
+ continue
+ }
+ for importPath := range p.Imports {
+ if _, ok := pkgs[importPath]; ok {
+ // imports a package dependent on pkgs, add it
+ pkgs[p.PkgPath] = p
+ changed = true
+ break
+ }
+ }
+ }
+ if !changed {
+ break
+ }
+ }
+}
+
+// testJSON is a union of BuildEvent and TestEvent
+type testJSON struct {
+ // TestEvent only:
+ // The Time field holds the time the event happened. It is conventionally omitted
+ // for cached test results.
+ Time time.Time `json:"Time"`
+ // BuildEvent only:
+ // The ImportPath field gives the package ID of the package being built.
+ // This matches the Package.ImportPath field of go list -json and the
+ // TestEvent.FailedBuild field of go test -json. Note that it does not
+ // match TestEvent.Package.
+ ImportPath string `json:"ImportPath"` // BuildEvent only
+ // TestEvent only:
+ // The Package field, if present, specifies the package being tested. When the
+ // go command runs parallel tests in -json mode, events from different tests are
+ // interlaced; the Package field allows readers to separate them.
+ Package string `json:"Package"`
+ // Action is used in both BuildEvent and TestEvent.
+ // It is the key to distinguishing between them.
+ // BuildEvent:
+ // build-output or build-fail
+ // TestEvent:
+ // start, run, pause, cont, pass, bench, fail, output, skip
+ Action string `json:"Action"`
+ // TestEvent only:
+ // The Test field, if present, specifies the test, example, or benchmark function
+ // that caused the event. Events for the overall package test do not set Test.
+ Test string `json:"Test"`
+ // TestEvent only:
+ // The Elapsed field is set for "pass" and "fail" events. It gives the time elapsed in seconds
+ // for the specific test or the overall package test that passed or failed.
+ Elapsed float64
+ // TestEvent:
+ // The Output field is set for Action == "output" and is a portion of the
+ // test's output (standard output and standard error merged together). The
+ // output is unmodified except that invalid UTF-8 output from a test is coerced
+ // into valid UTF-8 by use of replacement characters. With that one exception,
+ // the concatenation of the Output fields of all output events is the exact output
+ // of the test execution.
+ // BuildEvent:
+ // The Output field is set for Action == "build-output" and is a portion of
+ // the build's output. The concatenation of the Output fields of all output
+ // events is the exact output of the build. A single event may contain one
+ // or more lines of output and there may be more than one output event for
+ // a given ImportPath. This matches the definition of the TestEvent.Output
+ // field produced by go test -json.
+ Output string `json:"Output"`
+ // TestEvent only:
+ // The FailedBuild field is set for Action == "fail" if the test failure was caused
+ // by a build failure. It contains the package ID of the package that failed to
+ // build. This matches the ImportPath field of the "go list" output, as well as the
+ // BuildEvent.ImportPath field as emitted by "go build -json".
+ FailedBuild string `json:"FailedBuild"`
+}
+
+// parseTestResults converts test output in JSONL format into a slice of testJSON objects
+func parseTestResults(testOutput []byte) ([]testJSON, error) {
+ var results []testJSON
+ dec := json.NewDecoder(bytes.NewReader(testOutput))
+ for {
+ var event testJSON
+ if err := dec.Decode(&event); err != nil {
+ if err == io.EOF {
+ break
+ }
+ return nil, err
+ }
+ results = append(results, event)
+ }
+ return results, nil
+}
+
+// testStatus represents the status of a test in a given commit
+type testStatus int
+
+const (
+ testStatusUnknown testStatus = iota
+ testStatusPass
+ testStatusFail
+ testStatusBuildFail
+ testStatusSkip
+)
+
+// testInfo represents information about a specific test
+type testInfo struct {
+ Package string
+ Test string // empty for package tests
+}
+
+// String returns a human-readable string representation of the test
+func (t testInfo) String() string {
+ if t.Test == "" {
+ return t.Package
+ }
+ return fmt.Sprintf("%s.%s", t.Package, t.Test)
+}
+
+// testRegression represents a test that regressed between commits
+type testRegression struct {
+ Info testInfo
+ BeforeStatus testStatus
+ AfterStatus testStatus
+ Output string // failure output in the after state
+}
+
+// collectTestStatuses processes a slice of test events and returns a map of test statuses
+func collectTestStatuses(results []testJSON) map[testInfo]testStatus {
+ statuses := make(map[testInfo]testStatus)
+ failedBuilds := make(map[string]bool) // track packages with build failures
+ testOutputs := make(map[testInfo][]string) // collect output for failing tests
+
+ // First pass: identify build failures
+ for _, result := range results {
+ if result.Action == "fail" && result.FailedBuild != "" {
+ failedBuilds[result.FailedBuild] = true
+ }
+ }
+
+ // Second pass: collect test statuses
+ for _, result := range results {
+ info := testInfo{Package: result.Package, Test: result.Test}
+
+ // Skip output events for now, we'll process them in a separate pass
+ if result.Action == "output" {
+ if result.Test != "" { // only collect output for actual tests, not package messages
+ testOutputs[info] = append(testOutputs[info], result.Output)
+ }
+ continue
+ }
+
+ // Handle BuildEvent output
+ if result.Action == "build-fail" {
+ // Mark all tests in this package as build failures
+ for ti := range statuses {
+ if ti.Package == result.ImportPath {
+ statuses[ti] = testStatusBuildFail
+ }
+ }
+ continue
+ }
+
+ // Check if the package has a build failure
+ if _, hasBuildFailure := failedBuilds[result.Package]; hasBuildFailure {
+ statuses[info] = testStatusBuildFail
+ continue
+ }
+
+ // Handle test events
+ switch result.Action {
+ case "pass":
+ statuses[info] = testStatusPass
+ case "fail":
+ statuses[info] = testStatusFail
+ case "skip":
+ statuses[info] = testStatusSkip
+ }
+ }
+
+ return statuses
+}
+
+// compareTestResults identifies tests that have regressed between commits
+func (r *CodeReviewer) compareTestResults(beforeResults, afterResults []testJSON) ([]testRegression, error) {
+ beforeStatuses := collectTestStatuses(beforeResults)
+ afterStatuses := collectTestStatuses(afterResults)
+
+ // Collect output for failing tests
+ testOutputMap := make(map[testInfo]string)
+ for _, result := range afterResults {
+ if result.Action == "output" {
+ info := testInfo{Package: result.Package, Test: result.Test}
+ testOutputMap[info] += result.Output
+ }
+ }
+
+ var regressions []testRegression
+
+ // Look for tests that regressed
+ for info, afterStatus := range afterStatuses {
+ // Skip tests that are passing or skipped in the after state
+ if afterStatus == testStatusPass || afterStatus == testStatusSkip {
+ continue
+ }
+
+ // Get the before status (default to unknown if not present)
+ beforeStatus, exists := beforeStatuses[info]
+ if !exists {
+ beforeStatus = testStatusUnknown
+ }
+
+ // Log warning if we encounter unexpected unknown status in the 'after' state
+ if afterStatus == testStatusUnknown {
+ slog.WarnContext(context.Background(), "Unexpected unknown test status encountered",
+ "package", info.Package, "test", info.Test)
+ }
+
+ // Check for regressions
+ if isRegression(beforeStatus, afterStatus) {
+ regressions = append(regressions, testRegression{
+ Info: info,
+ BeforeStatus: beforeStatus,
+ AfterStatus: afterStatus,
+ Output: testOutputMap[info],
+ })
+ }
+ }
+
+ // Sort regressions for consistent output
+ slices.SortFunc(regressions, func(a, b testRegression) int {
+ // First by package
+ if c := strings.Compare(a.Info.Package, b.Info.Package); c != 0 {
+ return c
+ }
+ // Then by test name
+ return strings.Compare(a.Info.Test, b.Info.Test)
+ })
+
+ return regressions, nil
+}
+
+// badnessLevels maps test status to a badness level
+// Higher values indicate worse status (more severe issues)
+var badnessLevels = map[testStatus]int{
+ testStatusBuildFail: 4, // Worst
+ testStatusFail: 3,
+ testStatusSkip: 2,
+ testStatusPass: 1,
+ testStatusUnknown: 0, // Least bad - avoids false positives
+}
+
+// isRegression determines if a test has regressed based on before and after status
+// A regression is defined as an increase in badness level
+func isRegression(before, after testStatus) bool {
+ // Higher badness level means worse status
+ return badnessLevels[after] > badnessLevels[before]
+}
+
+// formatTestRegressions generates a human-readable summary of test regressions
+func (r *CodeReviewer) formatTestRegressions(regressions []testRegression) string {
+ if len(regressions) == 0 {
+ return ""
+ }
+
+ var sb strings.Builder
+ sb.WriteString(fmt.Sprintf("Test regressions detected between initial commit (%s) and HEAD:\n\n", r.initialCommit))
+
+ for i, reg := range regressions {
+ // Describe the regression
+ sb.WriteString(fmt.Sprintf("%d. %s: ", i+1, reg.Info.String()))
+
+ switch {
+ case reg.BeforeStatus == testStatusUnknown && reg.AfterStatus == testStatusFail:
+ sb.WriteString("New test is failing")
+ case reg.BeforeStatus == testStatusUnknown && reg.AfterStatus == testStatusBuildFail:
+ sb.WriteString("New test has build errors")
+ case reg.BeforeStatus == testStatusPass && reg.AfterStatus == testStatusFail:
+ sb.WriteString("Was passing, now failing")
+ case reg.BeforeStatus == testStatusPass && reg.AfterStatus == testStatusBuildFail:
+ sb.WriteString("Was passing, now has build errors")
+ case reg.BeforeStatus == testStatusSkip && reg.AfterStatus == testStatusFail:
+ sb.WriteString("Was skipped, now failing")
+ case reg.BeforeStatus == testStatusSkip && reg.AfterStatus == testStatusBuildFail:
+ sb.WriteString("Was skipped, now has build errors")
+ default:
+ sb.WriteString("Regression detected")
+ }
+ sb.WriteString("\n")
+
+ // Add failure output with indentation for readability
+ if reg.Output != "" {
+ outputLines := strings.Split(strings.TrimSpace(reg.Output), "\n")
+ // Limit output to first 10 lines to avoid overwhelming feedback
+ shownLines := min(len(outputLines), 10)
+
+ sb.WriteString(" Output:\n")
+ for _, line := range outputLines[:shownLines] {
+ sb.WriteString(fmt.Sprintf(" | %s\n", line))
+ }
+ if shownLines < len(outputLines) {
+ sb.WriteString(fmt.Sprintf(" | ... (%d more lines)\n", len(outputLines)-shownLines))
+ }
+ }
+ sb.WriteString("\n")
+ }
+
+ sb.WriteString("Please fix these test failures before proceeding.")
+ return sb.String()
+}