fix: deduplicate bulk commits (#2758)

Deduplicate nested commits with the same subject and library ID.

Fixes #2690

Author: JoeWang1127

internal/gitrepo/conventional_commits.go

@@ -139,16 +139,21 @@ func ParseCommits(commit *Commit, libraryID string) ([]*ConventionalCommit, erro
 	message = extractBeginCommitMessage(message)
 
 	var commits []*ConventionalCommit
-
+	seen := make(map[string]bool)
 	for _, part := range extractCommitParts(message) {
-		c, err := parseSimpleCommit(part, commit, libraryID)
+		simpleCommits, err := parseSimpleCommit(part, commit, libraryID)
 		if err != nil {
 			slog.Warn("failed to parse commit part", "commit", part.message, "error", err)
 			continue
 		}
 
-		if c != nil {
-			commits = append(commits, c...)
+		for _, simpleCommit := range simpleCommits {
+			key := fmt.Sprintf("%s,%s", simpleCommit.Subject, simpleCommit.LibraryID)
+			if _, ok := seen[key]; ok {
+				continue
+			}
+			seen[key] = true
+			commits = append(commits, simpleCommit)
 		}
 	}
 

internal/gitrepo/conventional_commits_test.go

@@ -601,6 +601,30 @@ END_COMMIT`,
 				},
 			},
 		},
+		{
+			name: "nested_commits_with_identical_message",
+			message: `
+BEGIN_NESTED_COMMIT
+fix(abc): update google.golang.org/api to 0.229.0
+END_NESTED_COMMIT
+BEGIN_NESTED_COMMIT
+fix(def): update google.golang.org/api to 0.229.0
+END_NESTED_COMMIT
+BEGIN_NESTED_COMMIT
+fix(cba): update google.golang.org/api to 0.229.0
+END_NESTED_COMMIT`,
+			want: []*ConventionalCommit{
+				{
+					Type:       "fix",
+					Subject:    "update google.golang.org/api to 0.229.0",
+					LibraryID:  "example-id",
+					IsNested:   true,
+					Footers:    map[string]string{},
+					CommitHash: sha.String(),
+					When:       now,
+				},
+			},
+		},
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			commit := &Commit{