feat(pierre): sanity check

internal/gitadapters/bitbucket/adapter_test.go

@@ -0,0 +1,80 @@
+package bitbucket
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestBitbucketGetFileContentSuccess(t *testing.T) {
+	const expected = "file content"
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// Verify path structure
+		if r.URL.Path != "/rest/api/1.0/projects/owner/repos/repo/raw/path/to/file.go" {
+			t.Fatalf("unexpected URL path: %s", r.URL.Path)
+		}
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte(expected))
+	}))
+	defer server.Close()
+
+	// Trim trailing slash handling done in NewBitbucket
+	adapter := NewBitbucket(server.URL, "")
+	content, err := adapter.GetFileContent(context.Background(), "owner", "repo", "path/to/file.go", "")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if content != expected {
+		t.Fatalf("expected %q, got %q", expected, content)
+	}
+}
+
+func TestBitbucketGetFileContentError(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusNotFound)
+		w.Write([]byte("not found"))
+	}))
+	defer server.Close()
+
+	adapter := NewBitbucket(server.URL, "")
+	_, err := adapter.GetFileContent(context.Background(), "owner", "repo", "missing.go", "")
+	if err == nil {
+		t.Fatalf("expected error for non‑200 response")
+	}
+}
+
+func TestBitbucketGetPRHeadSHASuccess(t *testing.T) {
+	const sha = "deadbeef"
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/rest/api/1.0/projects/owner/repos/repo/pull-requests/42" {
+			t.Fatalf("unexpected URL: %s", r.URL.Path)
+		}
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte(`{"toRef":{"latestCommit":"` + sha + `"}}`))
+	}))
+	defer server.Close()
+
+	adapter := NewBitbucket(server.URL, "")
+	got, err := adapter.GetPRHeadSHA(context.Background(), "owner", "repo", 42)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if got != sha {
+		t.Fatalf("expected sha %s, got %s", sha, got)
+	}
+}
+
+func TestBitbucketGetPRHeadSHAError(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusInternalServerError)
+		w.Write([]byte("error"))
+	}))
+	defer server.Close()
+
+	adapter := NewBitbucket(server.URL, "")
+	_, err := adapter.GetPRHeadSHA(context.Background(), "owner", "repo", 1)
+	if err == nil {
+		t.Fatalf("expected error for non‑200 response")
+	}
+}

internal/gitadapters/bitbucket/controller.go

@@ -47,10 +47,10 @@ func (b *BitbucketAdapter) GetPR(ctx context.Context, projectKey, repositorySlug
 	)
 
 	response, err := http.DefaultClient.Do(r)
-	defer response.Body.Close() // Add this
 	if err != nil {
 		return
 	}
+	defer response.Body.Close() // Add this
 
 	err = json.NewDecoder(response.Body).Decode(&pr)
 
@@ -86,10 +86,10 @@ func (b *BitbucketAdapter) AddComment(ctx context.Context, owner, repo string, p
 	}
 
 	response, err := http.DefaultClient.Do(r)
-	defer response.Body.Close() // Add this
 	if err != nil {
 		return err
 	}
+	defer response.Body.Close() // Add this
 
 	if response.StatusCode >= 300 || response.StatusCode < 200 {
 		sb := &strings.Builder{}

internal/gitadapters/bitbucket/resource.go

@@ -1,6 +1,10 @@
 package bitbucket
 
 import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
 	"strings"
 
 	"git.schreifuchs.ch/schreifuchs/pierre-bot/internal/gitadapters/baseadapter"
@@ -18,3 +22,43 @@ func NewBitbucket(baseURL string, bearerToken string) *BitbucketAdapter {
 		Rest: baseadapter.NewRest(baseURL, bearerToken),
 	}
 }
+
+// GetFileContent returns the raw file content at the given ref (commit SHA) or HEAD if ref is empty.
+func (b *BitbucketAdapter) GetFileContent(ctx context.Context, projectKey, repositorySlug, path, ref string) (string, error) {
+	// Use the Rest helper to build the base URL, then add the "at" query param if needed.
+	r, err := b.CreateRequest(ctx, http.MethodGet, nil,
+		"/projects/", projectKey, "repos", repositorySlug, "raw", path)
+	if err != nil {
+		return "", err
+	}
+	if ref != "" {
+		q := r.URL.Query()
+		q.Set("at", ref)
+		r.URL.RawQuery = q.Encode()
+	}
+
+	resp, err := http.DefaultClient.Do(r)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		sb := &strings.Builder{}
+		io.Copy(sb, resp.Body)
+		return "", fmt.Errorf("error fetching file %s status %d, body %s", path, resp.StatusCode, sb.String())
+	}
+	content, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+	return string(content), nil
+}
+
+// GetPRHeadSHA fetches the PR and returns the SHA of the source (to) branch.
+func (b *BitbucketAdapter) GetPRHeadSHA(ctx context.Context, projectKey, repositorySlug string, pullRequestID int) (string, error) {
+	pr, err := b.GetPR(ctx, projectKey, repositorySlug, pullRequestID)
+	if err != nil {
+		return "", err
+	}
+	return pr.ToRef.LatestCommit, nil
+}

internal/gitadapters/gitea/adapter.go

@@ -3,6 +3,7 @@ package gitea
 import (
 	"bytes"
 	"context"
+	"fmt"
 	"io"
 
 	"code.gitea.io/sdk/gitea"
@@ -47,3 +48,28 @@ func (g *Adapter) AddComment(ctx context.Context, owner, repo string, prID int,
 	_, _, err := g.client.CreatePullReview(owner, repo, int64(prID), opts)
 	return err
 }
+
+// GetFileContent returns the file content at a given path and ref (commit SHA).
+func (g *Adapter) GetFileContent(ctx context.Context, owner, repo, path, ref string) (string, error) {
+	g.client.SetContext(ctx)
+	// The SDK's GetFile returns the raw bytes of the file.
+	data, _, err := g.client.GetFile(owner, repo, ref, path)
+	if err != nil {
+		return "", err
+	}
+	return string(data), nil
+}
+
+// GetPRHeadSHA fetches the pull request and returns the head commit SHA.
+func (g *Adapter) GetPRHeadSHA(ctx context.Context, owner, repo string, prID int) (string, error) {
+	g.client.SetContext(ctx)
+	// GetPullRequest returns the detailed PR information.
+	pr, _, err := g.client.GetPullRequest(owner, repo, int64(prID))
+	if err != nil {
+		return "", err
+	}
+	if pr == nil || pr.Head == nil {
+		return "", fmt.Errorf("pull request %d has no head information", prID)
+	}
+	return pr.Head.Sha, nil
+}

internal/pierre/judge.go

@@ -88,6 +88,10 @@ If project guidelines are provided, treat them as hard rules that must be respec
 // It tries to split on file boundaries ("diff --git") first, then on hunk boundaries (@@),
 // and finally on a hard byte limit.
 func splitDiffIntoChunks(diff []byte, maxSize int) []string {
+	// Preserve the file header for each chunk when a single file's diff is split across multiple chunks.
+	// The header is the portion before the first hunk marker "@@" (including the "diff --git" line).
+	// When we need to split by hunks, we prepend this header to every resulting sub‑chunk.
+
 	if len(diff) <= maxSize {
 		return []string{string(diff)}
 	}
@@ -107,22 +111,31 @@ func splitDiffIntoChunks(diff []byte, maxSize int) []string {
 			current.Reset()
 		}
 		if len(seg) > maxSize {
-			// Split further by hunks
-			hunks := strings.Split(seg, "\n@@ ")
-			for j, h := range hunks {
-				var hseg string
-				if j == 0 {
-					// First hunk segment already contains the preceding content (including any needed newline)
-					hseg = h
-				} else {
-					// Subsequent hunks need the leading newline and "@@ " marker restored
-					hseg = "\n@@ " + h
+			// Determine if there is a hunk marker. If not, fall back to simple size‑based chunking.
+			headerEnd := strings.Index(seg, "\n@@ ")
+			if headerEnd == -1 {
+				// No hunk marker – split purely by size.
+				remaining := seg
+				for len(remaining) > maxSize {
+					chunks = append(chunks, remaining[:maxSize])
+					remaining = remaining[maxSize:]
 				}
+				current.WriteString(remaining)
+				continue
+			}
+			// Preserve the header up to the first hunk.
+			header := seg[:headerEnd+1] // include newline before "@@"
+			// Split the rest of the segment into hunks (excluding the header part).
+			hunks := strings.Split(strings.TrimPrefix(seg, header), "\n@@ ")
+			for _, h := range hunks {
+				// Reconstruct each hunk with its header and "@@ " prefix.
+				hseg := header + "@@ " + h
 				if current.Len()+len(hseg) > maxSize && current.Len() > 0 {
 					chunks = append(chunks, current.String())
 					current.Reset()
 				}
 				if len(hseg) > maxSize {
+					// If a single hunk exceeds maxSize, split it further.
 					for len(hseg) > maxSize {
 						chunks = append(chunks, hseg[:maxSize])
 						hseg = hseg[maxSize:]

internal/pierre/judge_test.go

@@ -37,6 +37,15 @@ func (g *mockGit) AddComment(ctx context.Context, owner, repo string, prID int,
 	return nil
 }
 
+func (g *mockGit) GetFileContent(ctx context.Context, owner, repo, path, ref string) (string, error) {
+	// For tests, return a simple placeholder content.
+	return "package main\n\nfunc placeholder() {}", nil
+}
+
+func (g *mockGit) GetPRHeadSHA(ctx context.Context, owner, repo string, prID int) (string, error) {
+	return "dummysha", nil
+}
+
 func TestSplitDiffIntoChunks(t *testing.T) {
 	cases := []struct {
 		name           string

internal/pierre/resource.go

@@ -33,6 +33,8 @@ func New(chat ChatAdapter, git GitAdapter, maxChunkSize int, guidelines []string
 type GitAdapter interface {
 	GetDiff(ctx context.Context, owner, repo string, prID int) (io.ReadCloser, error)
 	AddComment(ctx context.Context, owner, repo string, prID int, comment Comment) error
+	GetFileContent(ctx context.Context, owner, repo, path, ref string) (string, error)
+	GetPRHeadSHA(ctx context.Context, owner, repo string, prID int) (string, error)
 }
 
 type ChatAdapter interface {

internal/pierre/review.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"fmt"
 	"log"
+
+	"git.schreifuchs.ch/schreifuchs/pierre-bot/internal/chatter"
 )
 
 func (s *Service) MakeReview(ctx context.Context, organisation string, repo string, prID int) error {
@@ -20,6 +22,46 @@ func (s *Service) MakeReview(ctx context.Context, organisation string, repo stri
 		return fmt.Errorf("error judging PR: %w", err)
 	}
 
+	// ---------- Sanity‑check step (always enabled) ----------
+	headSHA, err := s.git.GetPRHeadSHA(ctx, organisation, repo, prID)
+	if err != nil {
+		log.Printf("warning: could not fetch PR head SHA (%v); skipping sanity check", err)
+	} else {
+		filtered := []Comment{}
+		for _, c := range comments {
+			// Retrieve full file content at the PR head
+			fileContent, fErr := s.git.GetFileContent(ctx, organisation, repo, c.File, headSHA)
+			if fErr != nil {
+				log.Printf("failed to fetch file %s: %v – keeping original comment", c.File, fErr)
+				filtered = append(filtered, c)
+				continue
+			}
+
+			// Build a simple sanity‑check prompt
+			systemPrompt := `You are a senior software architect. Given the full source code of a file and a review comment that refers to it, decide whether the comment is useful. Return JSON with fields "useful" (bool) and "reason" (short explanation, ≤2 sentences).`
+			userPrompt := fmt.Sprintf("File content:\n%s\n\nComment:\n%s", fileContent, c.Message)
+
+			type sanityResult struct {
+				Useful bool   `json:"useful"`
+				Reason string `json:"reason"`
+			}
+			var res sanityResult
+			if err := s.chat.GenerateStructured(ctx, []chatter.Message{{Role: chatter.RoleSystem, Content: systemPrompt}, {Role: chatter.RoleUser, Content: userPrompt}}, &res); err != nil {
+				log.Printf("sanity check error for %s:%d: %v – keeping comment", c.File, c.Line, err)
+				filtered = append(filtered, c)
+				continue
+			}
+			if res.Useful {
+				// Optionally annotate the comment with the reason for debugging
+				c.Message = fmt.Sprintf("%s (Reason: %s)", c.Message, res.Reason)
+				filtered = append(filtered, c)
+			} else {
+				log.Printf("comment on %s:%d discarded: %s", c.File, c.Line, res.Reason)
+			}
+		}
+		comments = filtered
+	}
+
 	fmt.Printf("Analysis complete. Found %d issues.\n---\n", len(comments))
 
 	model := s.chat.GetProviderName()