Add move operation for commits

README.md

@@ -311,6 +311,28 @@ or a repository-scoped LFS object already uploaded and verified through the LFS
 
 `blobSha` and `lfs` are mutually exclusive. `executable` is optional for puts. A `delete` operation takes only `op` and `path`.
 
+A `move` relocates a file or a whole directory tree:
+
+```json
+{
+  "op": "move",
+  "fromPath": "plugins",
+  "path": "server/plugins"
+}
+```
+
+Operations are applied in array order. After the move, later operations in the same request use the destination path:
+
+```json
+{
+  "operations": [
+    { "op": "move", "fromPath": "plugins", "path": "server/plugins" },
+    { "op": "put", "path": "server/plugins/config.yml", "blobSha": "<sha>" },
+    { "op": "delete", "path": "server/plugins/something.yaml" }
+  ]
+}
+```
+
 `expectedHeadSha` controls concurrency:
 
 | Value            | Meaning                                                                                  |

internal/domain/commit.go

@@ -23,6 +23,7 @@ type CommitFileLfsObject struct {
 
 type CommitFileOp struct {
 	Delete     bool
+	MoveFrom   string
 	Path       string
 	BlobSHA    *string
 	Lfs        *CommitFileLfsObject

internal/gitbackend/backend.go

@@ -20,6 +20,6 @@ type Backend interface {
 	StatBlob(ctx context.Context, storagePath, rev, treePath string) (BlobInfo, error)
 	ReadBlob(ctx context.Context, storagePath, blobSHA string, out io.Writer) error
 	WriteBlob(ctx context.Context, storagePath string, r io.Reader) (string, int64, error)
-	ApplyCommit(ctx context.Context, storagePath string, spec CommitSpec, ops []CommitOp, clean CleanFunc) (RefChange, error)
+	ApplyCommit(ctx context.Context, storagePath string, spec CommitSpec, ops []CommitOp, clean CleanFunc, checkWrite CheckWriteFunc) (RefChange, error)
 	GC(ctx context.Context, storagePath string) error
 }

internal/gitbackend/errors.go

@@ -7,6 +7,7 @@ var (
 	ErrInvalidPath  = errors.New("invalid tree path")
 	ErrRevNotFound  = errors.New("revision not found")
 	ErrPathNotFound = errors.New("path not found in tree")
+	ErrPathExists   = errors.New("path already exists in tree")
 	ErrNotABlob     = errors.New("path is not a blob")
 
 	// commit creation