feat(cmds): support snippet text edit

rust-lang/rust-analyzer#4494

Author: fannheyward

src/client.ts

@@ -1,4 +1,26 @@
-import { Executable, LanguageClient, LanguageClientOptions, ServerOptions, Uri, workspace } from 'coc.nvim';
+import { Executable, LanguageClient, LanguageClientOptions, ServerOptions, StaticFeature, Uri, workspace } from 'coc.nvim';
+import { ClientCapabilities, CodeAction, CodeActionParams, CodeActionRequest, Command, InsertTextFormat, TextDocumentEdit } from 'vscode-languageserver-protocol';
+
+class SnippetTextEditFeature implements StaticFeature {
+  fillClientCapabilities(capabilities: ClientCapabilities): void {
+    const caps: any = capabilities.experimental ?? {};
+    caps.snippetTextEdit = true;
+    capabilities.experimental = caps;
+  }
+  initialize(): void {}
+}
+
+function isSnippetEdit(action: CodeAction): boolean {
+  const documentChanges = action.edit?.documentChanges ?? [];
+  for (const edit of documentChanges) {
+    if (TextDocumentEdit.is(edit)) {
+      if (edit.edits.some((indel) => (indel as any).insertTextFormat === InsertTextFormat.Snippet)) {
+        return true;
+      }
+    }
+  }
+  return false;
+}
 
 export function createClient(bin: string): LanguageClient {
   let folder = '.';
@@ -24,6 +46,26 @@ export function createClient(bin: string): LanguageClient {
         position.character = character - 1;
         return help;
       },
+      provideCodeActions(document, range, context, token) {
+        const params: CodeActionParams = {
+          textDocument: { uri: document.uri },
+          range,
+          context,
+        };
+        // eslint-disable-next-line @typescript-eslint/no-use-before-define
+        return client.sendRequest(CodeActionRequest.type, params, token).then((values) => {
+          if (values === null) return undefined;
+          const result: (CodeAction | Command)[] = [];
+          for (const item of values) {
+            if (CodeAction.is(item) && isSnippetEdit(item)) {
+              item.command = Command.create('', 'rust-analyzer.applySnippetWorkspaceEdit', item.edit);
+              item.edit = undefined;
+            }
+            result.push(item);
+          }
+          return result;
+        });
+      },
     },
     outputChannel,
   };
@@ -51,5 +93,7 @@ export function createClient(bin: string): LanguageClient {
     },
   };
   client.registerProposedFeatures();
+  client.registerFeature(new SnippetTextEditFeature());
+
   return client;
 }

src/cmds/index.ts

@@ -1,5 +1,5 @@
 import { commands, Uri, workspace } from 'coc.nvim';
-import { Location, Position } from 'vscode-languageserver-protocol';
+import { Location, Position, Range, TextDocumentEdit, TextEdit, WorkspaceEdit } from 'vscode-languageserver-protocol';
 import { Cmd, Ctx } from '../ctx';
 import * as ra from '../rust-analyzer-api';
 import * as sourceChange from '../source_change';
@@ -67,3 +67,32 @@ export function toggleInlayHints(ctx: Ctx) {
     }
   };
 }
+
+export function applySnippetWorkspaceEdit(): Cmd {
+  return async (edit: WorkspaceEdit) => {
+    if (edit.documentChanges && edit.documentChanges.length) {
+      let editWithSnippet: TextEdit | undefined = undefined;
+      let lineDelta = 0;
+
+      const edits = (edit.documentChanges as TextDocumentEdit[])[0].edits;
+      for (const indel of edits) {
+        const isSnippet = indel.newText.indexOf('$0') !== -1 || indel.newText.indexOf('${') !== -1;
+        if (isSnippet) {
+          editWithSnippet = indel;
+        } else {
+          if (!editWithSnippet) {
+            lineDelta = (indel.newText.match(/\n/g) || []).length - (indel.range.end.line - indel.range.start.line);
+          }
+          TextEdit.replace(indel.range, indel.newText);
+        }
+      }
+
+      if (editWithSnippet) {
+        const snip = editWithSnippet as TextEdit;
+        const range = Range.create(snip.range.start.line + lineDelta, snip.range.start.character, snip.range.end.line + lineDelta, snip.range.end.character);
+        snip.range = range;
+        await commands.executeCommand('editor.action.insertSnippet', snip);
+      }
+    }
+  };
+}

src/index.ts

@@ -38,6 +38,7 @@ export async function activate(context: ExtensionContext): Promise<void> {
 
   ctx.registerCommand('analyzerStatus', cmds.analyzerStatus);
   ctx.registerCommand('applySourceChange', cmds.applySourceChange);
+  ctx.registerCommand('applySnippetWorkspaceEdit', cmds.applySnippetWorkspaceEdit);
   ctx.registerCommand('selectAndApplySourceChange', cmds.selectAndApplySourceChange);
   ctx.registerCommand('collectGarbage', cmds.collectGarbage);
   ctx.registerCommand('expandMacro', cmds.expandMacro);