Add support for reading git notes

go-git · JakobDev · Nov 16, 2023 · Nov 16, 2023 · 1d6fc434b3fd65f37120119615be9fbd54f96270 · pjbgf
commit 1d6fc434b3fd65f37120119615be9fbd54f96270
diff --git a/COMPATIBILITY.md b/COMPATIBILITY.md
@@ -116,12 +116,12 @@ compatibility status with go-git.
 
 ## Advanced
 
-| Feature    | Sub-feature | Status      | Notes | Examples |
-| ---------- | ----------- | ----------- | ----- | -------- |
-| `notes`    |             | ❌          |       |          |
-| `replace`  |             | ❌          |       |          |
-| `worktree` |             | ❌          |       |          |
-| `annotate` |             | (see blame) |       |          |
+| Feature    | Sub-feature | Status      | Notes         | Examples |
+| ---------- | ----------- | ----------- | ------------- | -------- |
+| `notes`    |             | ✅          | Only reading |          |
+| `replace`  |             | ❌          |              |          |
+| `worktree` |             | ❌          |              |          |
+| `annotate` |             | (see blame) |              |          |
 
 ## GPG
 

diff --git a/repository.go b/repository.go
@@ -1720,6 +1720,52 @@ func (r *Repository) resolveHashPrefix(hashStr string) []plumbing.Hash {
 	return hashes
 }
 
+// GetNote retuns the note for the given commit. returns a empty string, if the commit has no note.
+func (r *Repository) GetNote(commit *object.Commit) (string, error) {
+	notes, err := r.Notes()
+	if err != nil {
+		return "", err
+	}
+
+	noteRef, err := notes.Next()
+	if err != nil {
+		if errors.Is(err, io.EOF) {
+			return "", nil
+		}
+		return "", err
+	}
+
+	noteCommit, err := r.CommitObject(noteRef.Hash())
+	if err != nil {
+		return "", err
+	}
+
+	tree, err := noteCommit.Tree()
+	if err != nil {
+		return "", err
+	}
+
+	fi, err := tree.File(commit.Hash.String())
+	if err != nil {
+		if errors.Is(err, object.ErrFileNotFound) {
+			return "", nil
+		}
+		return "", err
+	}
+
+	reader, err := fi.Blob.Reader()
+	if err != nil {
+		return "", err
+	}
+
+	by, err := io.ReadAll(reader)
+	if err != nil {
+		return "", err
+	}
+
+	return strings.TrimSpace(string(by)), nil
+}
+
 type RepackConfig struct {
 	// UseRefDeltas configures whether packfile encoder will use reference deltas.
 	// By default OFSDeltaObject is used.

diff --git a/repository_test.go b/repository_test.go
@@ -3333,3 +3333,20 @@ func BenchmarkPlainClone(b *testing.B) {
 		clone(b)
 	}
 }
+
+func (s *RepositorySuite) TestGetNoteNotExisting(c *C) {
+	r, _ := Init(memory.NewStorage(), nil)
+	err := r.clone(context.Background(), &CloneOptions{URL: s.GetBasicLocalRepositoryURL()})
+	c.Assert(err, IsNil)
+
+	head, err := r.Head()
+	c.Assert(err, IsNil)
+
+	commit, err := r.CommitObject(head.Hash())
+	c.Assert(err, IsNil)
+
+	note, err := r.GetNote(commit)
+	c.Assert(err, IsNil)
+
+	c.Check(note, Equals, "")
+}