1 files changed, 28 insertions, 0 deletions
diff --git a/gopls/internal/lsp/work/format.go b/gopls/internal/lsp/work/format.go
new file mode 100644
index 000000000..e852eb4d2
--- /dev/null
+++ b/gopls/internal/lsp/work/format.go
@@ -0,0 +1,28 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package work
+
+import (
+	"context"
+
+	"golang.org/x/mod/modfile"
+	"golang.org/x/tools/gopls/internal/lsp/protocol"
+	"golang.org/x/tools/gopls/internal/lsp/source"
+	"golang.org/x/tools/internal/event"
+)
+
+func Format(ctx context.Context, snapshot source.Snapshot, fh source.FileHandle) ([]protocol.TextEdit, error) {
+	ctx, done := event.Start(ctx, "work.Format")
+	defer done()
+
+	pw, err := snapshot.ParseWork(ctx, fh)
+	if err != nil {
+		return nil, err
+	}
+	formatted := modfile.Format(pw.File.Syntax)
+	// Calculate the edits to be made due to the change.
+	diffs := snapshot.View().Options().ComputeEdits(string(pw.Mapper.Content), string(formatted))
+	return source.ToProtocolEdits(pw.Mapper, diffs)
+}