gopls/protocol: Allow AnnotatedTextEdits

In the LSP specification, the Edits fields of a TextdocumentEdit
are a union type TextEdit | AnnotatedTextEdit. The latter has an
extra field that might be useful.

This CL contains one way of allowing AnnotatedTextEdits in this
context. The systematic naming of union type provides this one
with a long name, Or_TextDocumentEdit_edits_Elem. Fortunately
this name appears in very few places.

Fitting the new type in the existing gopls code requires
1. Conversions between []newtype and []TextEdit. This code
is AsTextEdits() and AsAnnotatedTextEdits() in protocol/edits.go
1a. Because gopls does not insist on go1.20, slices of the new
type cannot be used as the argument to protocol.NonNilSlice(),
so the second function cannot return nil, but must return a slice.
2. There are some places where previously a TextEdit was built.
These now require explicitly constructing an element of the new type.

This CL does not make any use of AnnotatedTextEdits, but it does
make their use possible.

Change-Id: Ib167f057068a5921c77572c43dc985da0e6b19bc
Reviewed-on: https://go-review.googlesource.com/c/tools/+/547295
Run-TryBot: Peter Weinberger <pjw@google.com>
Reviewed-by: Suzy Mueller <suzmue@golang.org>
TryBot-Bypass: Peter Weinberger <pjw@google.com>

gopls/internal/cmd/cmd.go

@@ -554,7 +554,7 @@ func (cli *cmdClient) applyWorkspaceEdit(edit *protocol.WorkspaceEdit) error {
 	for _, c := range edit.DocumentChanges {
 		if c.TextDocumentEdit != nil {
 			uri := c.TextDocumentEdit.TextDocument.URI
-			edits[uri] = append(edits[uri], c.TextDocumentEdit.Edits...)
+			edits[uri] = append(edits[uri], protocol.AsTextEdits(c.TextDocumentEdit.Edits)...)
 			orderedURIs = append(orderedURIs, uri)
 		}
 		if c.RenameFile != nil {

gopls/internal/cmd/imports.go

@@ -71,7 +71,7 @@ func (t *imports) Run(ctx context.Context, args ...string) error {
 		for _, c := range a.Edit.DocumentChanges {
 			if c.TextDocumentEdit != nil {
 				if c.TextDocumentEdit.TextDocument.URI == uri {
-					edits = append(edits, c.TextDocumentEdit.Edits...)
+					edits = append(edits, protocol.AsTextEdits(c.TextDocumentEdit.Edits)...)
 				}
 			}
 		}

gopls/internal/cmd/suggested_fix.go

@@ -154,7 +154,7 @@ func (s *suggestedFix) Run(ctx context.Context, args ...string) error {
 			for _, c := range a.Edit.DocumentChanges {
 				if c.TextDocumentEdit != nil {
 					if c.TextDocumentEdit.TextDocument.URI == uri {
-						edits = append(edits, c.TextDocumentEdit.Edits...)
+						edits = append(edits, protocol.AsTextEdits(c.TextDocumentEdit.Edits)...)
 					}
 				}
 			}
@@ -168,7 +168,7 @@ func (s *suggestedFix) Run(ctx context.Context, args ...string) error {
 				for _, c := range a.Edit.DocumentChanges {
 					if c.TextDocumentEdit != nil {
 						if c.TextDocumentEdit.TextDocument.URI == uri {
-							edits = append(edits, c.TextDocumentEdit.Edits...)
+							edits = append(edits, protocol.AsTextEdits(c.TextDocumentEdit.Edits)...)
 						}
 					}
 				}
@@ -181,7 +181,7 @@ func (s *suggestedFix) Run(ctx context.Context, args ...string) error {
 			for _, c := range a.Edit.DocumentChanges {
 				if c.TextDocumentEdit != nil {
 					if c.TextDocumentEdit.TextDocument.URI == uri {
-						edits = append(edits, c.TextDocumentEdit.Edits...)
+						edits = append(edits, protocol.AsTextEdits(c.TextDocumentEdit.Edits)...)
 					}
 				}
 			}

gopls/internal/lsp/protocol/edits.go

@@ -4,7 +4,11 @@
 
 package protocol
 
-import "golang.org/x/tools/internal/diff"
+import (
+	"fmt"
+
+	"golang.org/x/tools/internal/diff"
+)
 
 // EditsFromDiffEdits converts diff.Edits to a non-nil slice of LSP TextEdits.
 // See https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textEditArray
@@ -60,3 +64,40 @@ func ApplyEdits(m *Mapper, edits []TextEdit) ([]byte, []diff.Edit, error) {
 	out, err := diff.ApplyBytes(m.Content, diffEdits)
 	return out, diffEdits, err
 }
+
+// AsTextEdits converts a slice possibly containing AnnotatedTextEdits
+// to a slice of TextEdits.
+func AsTextEdits(edits []Or_TextDocumentEdit_edits_Elem) []TextEdit {
+	var result []TextEdit
+	for _, e := range edits {
+		var te TextEdit
+		if x, ok := e.Value.(AnnotatedTextEdit); ok {
+			te = x.TextEdit
+		} else if x, ok := e.Value.(TextEdit); ok {
+			te = x
+		} else {
+			panic(fmt.Sprintf("unexpected type %T, expected AnnotatedTextEdit or TextEdit", e.Value))
+		}
+		result = append(result, te)
+	}
+	return result
+}
+
+// AsAnnotatedTextEdits converts a slice of TextEdits
+// to a slice of Or_TextDocumentEdit_edits_Elem.
+// (returning a typed nil is required in server: in code_action.go and command.go))
+func AsAnnotatedTextEdits(edits []TextEdit) []Or_TextDocumentEdit_edits_Elem {
+	if edits == nil {
+		return []Or_TextDocumentEdit_edits_Elem{}
+	}
+	var result []Or_TextDocumentEdit_edits_Elem
+	for _, e := range edits {
+		result = append(result, Or_TextDocumentEdit_edits_Elem{
+			Value: TextEdit{
+				Range:   e.Range,
+				NewText: e.NewText,
+			},
+		})
+	}
+	return result
+}

gopls/internal/lsp/protocol/generate/tables.go

@@ -24,6 +24,7 @@ const (
 // A.B.C.D means that one of B or C would change to a pointer
 // so a test or initialization would be needed
 var goplsStar = map[prop]int{
+	{"AnnotatedTextEdit", "annotationId"}:  wantOptStar,
 	{"ClientCapabilities", "textDocument"}: wantOpt, // A.B.C.D at fake/editor.go:255
 	{"ClientCapabilities", "window"}:       wantOpt, // test failures
 	{"ClientCapabilities", "workspace"}:    wantOpt, // test failures
@@ -85,7 +86,6 @@ var renameProp = map[prop]string{
 	{"ServerCapabilities", "semanticTokensProvider"}: "interface{}",
 	// slightly tricky
 	{"ServerCapabilities", "textDocumentSync"}: "interface{}",
-	{"TextDocumentEdit", "edits"}:              "[]TextEdit",
 	{"TextDocumentSyncOptions", "save"}:        "SaveOptions",
 	{"WorkspaceEdit", "documentChanges"}:       "[]DocumentChanges",
 }

gopls/internal/lsp/source/change_quote.go

@@ -85,7 +85,7 @@ func ConvertStringLiteral(pgf *ParsedGoFile, fh file.Handle, rng protocol.Range)
 							Version:                fh.Version(),
 							TextDocumentIdentifier: protocol.TextDocumentIdentifier{URI: fh.URI()},
 						},
-						Edits: pedits,
+						Edits: protocol.AsAnnotatedTextEdits(pedits),
 					},
 				},
 			},

gopls/internal/lsp/source/change_signature.go

@@ -176,7 +176,7 @@ func RemoveUnusedParameter(ctx context.Context, fh file.Handle, rng protocol.Ran
 					Version:                fh.Version(),
 					TextDocumentIdentifier: protocol.TextDocumentIdentifier{URI: uri},
 				},
-				Edits: pedits,
+				Edits: protocol.AsAnnotatedTextEdits(pedits),
 			},
 		})
 	}

gopls/internal/lsp/source/fix.go

@@ -130,9 +130,11 @@ func suggestedFixToEdits(ctx context.Context, snapshot *cache.Snapshot, fset *to
 		if err != nil {
 			return nil, err
 		}
-		te.Edits = append(te.Edits, protocol.TextEdit{
-			Range:   rng,
-			NewText: string(edit.NewText),
+		te.Edits = append(te.Edits, protocol.Or_TextDocumentEdit_edits_Elem{
+			Value: protocol.TextEdit{
+				Range:   rng,
+				NewText: string(edit.NewText),
+			},
 		})
 	}
 	var edits []protocol.TextDocumentEdit

gopls/internal/server/code_action.go

@@ -617,7 +617,7 @@ func documentChanges(fh file.Handle, edits []protocol.TextEdit) []protocol.Docum
 						URI: fh.URI(),
 					},
 				},
-				Edits: protocol.NonNilSlice(edits),
+				Edits: protocol.AsAnnotatedTextEdits(edits),
 			},
 		},
 	}

gopls/internal/server/command.go

@@ -451,7 +451,7 @@ func (c *commandHandler) RemoveDependency(ctx context.Context, args command.Remo
 									URI: deps.fh.URI(),
 								},
 							},
-							Edits: protocol.NonNilSlice(edits),
+							Edits: protocol.AsAnnotatedTextEdits(edits),
 						},
 					},
 				},
@@ -700,7 +700,7 @@ func collectFileEdits(ctx context.Context, snapshot *cache.Snapshot, uri protoco
 				URI: uri,
 			},
 		},
-		Edits: edits,
+		Edits: protocol.AsAnnotatedTextEdits(edits),
 	}}, nil
 }
 

gopls/internal/test/integration/fake/editor.go

@@ -910,7 +910,7 @@ func (e *Editor) ApplyCodeAction(ctx context.Context, action protocol.CodeAction
 					// Skip edits for old versions.
 					continue
 				}
-				if err := e.EditBuffer(ctx, path, change.TextDocumentEdit.Edits); err != nil {
+				if err := e.EditBuffer(ctx, path, protocol.AsTextEdits(change.TextDocumentEdit.Edits)); err != nil {
 					return fmt.Errorf("editing buffer %q: %w", path, err)
 				}
 			}
@@ -1361,7 +1361,7 @@ func (e *Editor) applyTextDocumentEdit(ctx context.Context, change protocol.Text
 			return err
 		}
 	}
-	return e.EditBuffer(ctx, path, change.Edits)
+	return e.EditBuffer(ctx, path, protocol.AsTextEdits(change.Edits))
 }
 
 // Config returns the current editor configuration.

gopls/internal/test/marker/marker_test.go

@@ -1650,7 +1650,7 @@ func applyDocumentChanges(env *integration.Env, changes []protocol.DocumentChang
 			if err != nil {
 				return err
 			}
-			patched, _, err := protocol.ApplyEdits(mapper, change.TextDocumentEdit.Edits)
+			patched, _, err := protocol.ApplyEdits(mapper, protocol.AsTextEdits(change.TextDocumentEdit.Edits))
 			if err != nil {
 				return err
 			}