--- /dev/null
+// Copyright 2019 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 cmd
+
+import (
+ "context"
+ "flag"
+ "fmt"
+ "io/ioutil"
+
+ "golang.org/x/tools/internal/lsp/diff"
+ "golang.org/x/tools/internal/lsp/protocol"
+ "golang.org/x/tools/internal/lsp/source"
+ "golang.org/x/tools/internal/span"
+ "golang.org/x/tools/internal/tool"
+ errors "golang.org/x/xerrors"
+)
+
+// suggestedFix implements the fix verb for gopls.
+type suggestedFix struct {
+ Diff bool `flag:"d" help:"display diffs instead of rewriting files"`
+ Write bool `flag:"w" help:"write result to (source) file instead of stdout"`
+ All bool `flag:"a" help:"apply all fixes, not just preferred fixes"`
+
+ app *Application
+}
+
+func (s *suggestedFix) Name() string { return "fix" }
+func (s *suggestedFix) Usage() string { return "<filename>" }
+func (s *suggestedFix) ShortHelp() string { return "apply suggested fixes" }
+func (s *suggestedFix) DetailedHelp(f *flag.FlagSet) {
+ fmt.Fprintf(f.Output(), `
+Example: apply suggested fixes for this file:
+
+ $ gopls fix -w internal/lsp/cmd/check.go
+
+gopls fix flags are:
+`)
+ f.PrintDefaults()
+}
+
+// Run performs diagnostic checks on the file specified and either;
+// - if -w is specified, updates the file in place;
+// - if -d is specified, prints out unified diffs of the changes; or
+// - otherwise, prints the new versions to stdout.
+func (s *suggestedFix) Run(ctx context.Context, args ...string) error {
+ if len(args) < 1 {
+ return tool.CommandLineErrorf("fix expects at least 1 argument")
+ }
+ conn, err := s.app.connect(ctx)
+ if err != nil {
+ return err
+ }
+ defer conn.terminate(ctx)
+
+ from := span.Parse(args[0])
+ uri := from.URI()
+ file := conn.AddFile(ctx, uri)
+ if file.err != nil {
+ return file.err
+ }
+
+ if err := conn.diagnoseFiles(ctx, []span.URI{uri}); err != nil {
+ return err
+ }
+ conn.Client.filesMu.Lock()
+ defer conn.Client.filesMu.Unlock()
+
+ codeActionKinds := []protocol.CodeActionKind{protocol.QuickFix}
+ if len(args) > 1 {
+ codeActionKinds = []protocol.CodeActionKind{}
+ for _, k := range args[1:] {
+ codeActionKinds = append(codeActionKinds, protocol.CodeActionKind(k))
+ }
+ }
+
+ rng, err := file.mapper.Range(from)
+ if err != nil {
+ return err
+ }
+ p := protocol.CodeActionParams{
+ TextDocument: protocol.TextDocumentIdentifier{
+ URI: protocol.URIFromSpanURI(uri),
+ },
+ Context: protocol.CodeActionContext{
+ Only: codeActionKinds,
+ Diagnostics: file.diagnostics,
+ },
+ Range: rng,
+ }
+ actions, err := conn.CodeAction(ctx, &p)
+ if err != nil {
+ return errors.Errorf("%v: %v", from, err)
+ }
+ var edits []protocol.TextEdit
+ for _, a := range actions {
+ if a.Command != nil {
+ return fmt.Errorf("ExecuteCommand is not yet supported on the command line")
+ }
+ if !a.IsPreferred && !s.All {
+ continue
+ }
+ if !from.HasPosition() {
+ for _, c := range a.Edit.DocumentChanges {
+ if fileURI(c.TextDocument.URI) == uri {
+ edits = append(edits, c.Edits...)
+ }
+ }
+ continue
+ }
+ // If the span passed in has a position, then we need to find
+ // the codeaction that has the same range as the passed in span.
+ for _, diag := range a.Diagnostics {
+ spn, err := file.mapper.RangeSpan(diag.Range)
+ if err != nil {
+ continue
+ }
+ if span.ComparePoint(from.Start(), spn.Start()) == 0 {
+ for _, c := range a.Edit.DocumentChanges {
+ if fileURI(c.TextDocument.URI) == uri {
+ edits = append(edits, c.Edits...)
+ }
+ }
+ break
+ }
+ }
+
+ // If suggested fix is not a diagnostic, still must collect edits.
+ if len(a.Diagnostics) == 0 {
+ for _, c := range a.Edit.DocumentChanges {
+ if fileURI(c.TextDocument.URI) == uri {
+ edits = append(edits, c.Edits...)
+ }
+ }
+ }
+ }
+
+ sedits, err := source.FromProtocolEdits(file.mapper, edits)
+ if err != nil {
+ return errors.Errorf("%v: %v", edits, err)
+ }
+ newContent := diff.ApplyEdits(string(file.mapper.Content), sedits)
+
+ filename := file.uri.Filename()
+ switch {
+ case s.Write:
+ if len(edits) > 0 {
+ ioutil.WriteFile(filename, []byte(newContent), 0644)
+ }
+ case s.Diff:
+ diffs := diff.ToUnified(filename+".orig", filename, string(file.mapper.Content), sedits)
+ fmt.Print(diffs)
+ default:
+ fmt.Print(string(newContent))
+ }
+ return nil
+}