knotserver/git: shared types and idomatic go

knotserver/git/merge.go

···
 	"github.com/go-git/go-git/v5/plumbing"
 )
 
-type MergeError struct {
+type ErrMerge struct {
 	Message     string
 	Conflicts   []ConflictInfo
 	HasConflict bool
···
 	Reason   string
 }
 
-func (e MergeError) Error() string {
+func (e ErrMerge) Error() string {
 	if e.HasConflict {
 		return fmt.Sprintf("merge failed due to conflicts: %s (%d conflicts)", e.Message, len(e.Conflicts))
 	}
···
 	if err := cmd.Run(); err != nil {
 		if checkOnly {
 			conflicts := parseGitApplyErrors(stderr.String())
-			return &MergeError{
+			return &ErrMerge{
 				Message:     "patch cannot be applied cleanly",
 				Conflicts:   conflicts,
 				HasConflict: len(conflicts) > 0,
···
 func (g *GitRepo) MergeCheck(patchData []byte, targetBranch string) error {
 	patchFile, err := g.createTempFileWithPatch(patchData)
 	if err != nil {
-		return &MergeError{
+		return &ErrMerge{
 			Message:    err.Error(),
 			OtherError: err,
 		}
···
 
 	tmpDir, err := g.cloneRepository(targetBranch)
 	if err != nil {
-		return &MergeError{
+		return &ErrMerge{
 			Message:    err.Error(),
 			OtherError: err,
 		}
···
 func (g *GitRepo) Merge(patchData []byte, targetBranch string) error {
 	patchFile, err := g.createTempFileWithPatch(patchData)
 	if err != nil {
-		return &MergeError{
+		return &ErrMerge{
 			Message:    err.Error(),
 			OtherError: err,
 		}
···
 
 	tmpDir, err := g.cloneRepository(targetBranch)
 	if err != nil {
-		return &MergeError{
+		return &ErrMerge{
 			Message:    err.Error(),
 			OtherError: err,
 		}
···
 
 	pushCmd := exec.Command("git", "-C", tmpDir, "push")
 	if err := pushCmd.Run(); err != nil {
-		return &MergeError{
+		return &ErrMerge{
 			Message:    "failed to push changes to bare repository",
 			OtherError: err,
 		}

knotserver/routes.go

···
 		notFound(w)
 		return
 	}
-
 	if err := gr.Merge([]byte(patch), branch); err != nil {
-		var mergeErr *git.MergeError
+		var mergeErr *git.ErrMerge
 		if errors.As(err, &mergeErr) {
-			conflictDetails := make([]map[string]interface{}, len(mergeErr.Conflicts))
+			conflicts := make([]types.ConflictInfo, len(mergeErr.Conflicts))
 			for i, conflict := range mergeErr.Conflicts {
-				conflictDetails[i] = map[string]interface{}{
-					"filename": conflict.Filename,
-					"reason":   conflict.Reason,
+				conflicts[i] = types.ConflictInfo{
+					Filename: conflict.Filename,
+					Reason:   conflict.Reason,
 				}
 			}
-			response := map[string]interface{}{
-				"message":   mergeErr.Message,
-				"conflicts": conflictDetails,
+			response := types.MergeCheckResponse{
+				IsConflicted: true,
+				Conflicts:    conflicts,
+				Message:      mergeErr.Message,
 			}
 			writeConflict(w, response)
 			h.l.Error("git: merge conflict", "handler", "Merge", "error", mergeErr)
···
 		return
 	}
 
-	var mergeErr *git.MergeError
+	var mergeErr *git.ErrMerge
 	if errors.As(err, &mergeErr) {
-		conflictDetails := make([]map[string]interface{}, len(mergeErr.Conflicts))
+		conflicts := make([]types.ConflictInfo, len(mergeErr.Conflicts))
 		for i, conflict := range mergeErr.Conflicts {
-			conflictDetails[i] = map[string]interface{}{
-				"filename": conflict.Filename,
-				"reason":   conflict.Reason,
+			conflicts[i] = types.ConflictInfo{
+				Filename: conflict.Filename,
+				Reason:   conflict.Reason,
 			}
 		}
-		response := map[string]interface{}{
-			"message":   mergeErr.Message,
-			"conflicts": conflictDetails,
+		response := types.MergeCheckResponse{
+			IsConflicted: true,
+			Conflicts:    conflicts,
+			Message:      mergeErr.Message,
 		}
 		writeConflict(w, response)
 		h.l.Error("git: merge conflict", "handler", "MergeCheck", "error", mergeErr.Error())
 		return
 	}
-
 	writeError(w, err.Error(), http.StatusInternalServerError)
 	h.l.Error("git: failed to check merge", "handler", "MergeCheck", "error", err.Error())
 }

types/merge.go

···
 package types
+
+type ConflictInfo struct {
+	Filename string `json:"filename"`
+	Reason   string `json:"reason"`
+}
+
+type MergeCheckResponse struct {
+	IsConflicted bool           `json:"is_conflicted"`
+	Conflicts    []ConflictInfo `json:"conflicts"`
+	Message      string         `json:"message"`
+	Error        string         `json:"error"`
+}