Implement code actions

This allows the user to remove unused anchors using quick actions.

src/languageFeatures.ts

@@ -1,6 +1,7 @@
 import {
   editor,
   IDisposable,
+  IRange,
   languages,
   MarkerSeverity,
   MarkerTag,
@@ -152,6 +153,22 @@ function toRange(range: ls.Range): Range {
   );
 }
 
+function fromRange(range: IRange): ls.Range {
+  return {
+    start: { line: range.startLineNumber - 1, character: range.startColumn - 1 },
+    end: { line: range.endLineNumber - 1, character: range.endColumn - 1 },
+  };
+}
+
+function fromMarkerData(marker: editor.IMarkerData): ls.Diagnostic {
+  return {
+    message: marker.message,
+    range: fromRange(marker),
+    code: typeof marker.code === 'object' ? marker.code.value : marker.code,
+    source: marker.source,
+  };
+}
+
 function toCompletionItemKind(kind: ls.CompletionItemKind): languages.CompletionItemKind {
   const mItemKind = languages.CompletionItemKind;
 
@@ -429,3 +446,55 @@ export function createLinkProvider(getWorker: WorkerAccessor): languages.LinkPro
     },
   };
 }
+
+function toWorkspaceEdit(edit: ls.WorkspaceEdit): languages.WorkspaceEdit {
+  const edits: languages.WorkspaceTextEdit[] = [];
+
+  for (const [uri, textEdits] of Object.entries(edit.changes)) {
+    for (const textEdit of textEdits) {
+      edits.push({
+        resource: Uri.parse(uri),
+        edit: {
+          text: textEdit.newText,
+          range: toRange(textEdit.range),
+        },
+      });
+    }
+  }
+
+  return {
+    edits,
+  };
+}
+
+function toCodeAction(codeAction: ls.CodeAction): languages.CodeAction {
+  return {
+    title: codeAction.title,
+    diagnostics: codeAction.diagnostics.map(toDiagnostics),
+    disabled: codeAction.disabled?.reason,
+    edit: toWorkspaceEdit(codeAction.edit),
+    kind: codeAction.kind,
+    isPreferred: codeAction.isPreferred,
+  };
+}
+
+export function createCodeActionProvider(getWorker: WorkerAccessor): languages.CodeActionProvider {
+  return {
+    async provideCodeActions(model, range, context) {
+      const resource = model.uri;
+
+      const worker = await getWorker(resource);
+      const codeActions = await worker.getCodeAction(
+        String(resource),
+        fromRange(range),
+        context.markers.map(fromMarkerData),
+      );
+      return {
+        actions: codeActions.map(toCodeAction),
+        dispose() {
+          // This is required by the TypeScript interface, but it’s not implemented.
+        },
+      };
+    },
+  };
+}

src/yamlMode.ts

@@ -2,6 +2,7 @@ import { languages } from 'monaco-editor/esm/vs/editor/editor.api.js';
 
 import { languageId } from './constants';
 import {
+  createCodeActionProvider,
   createCompletionItemProvider,
   createDefinitionProvider,
   createDiagnosticsAdapter,
@@ -56,6 +57,7 @@ export function setupMode(defaults: languages.yaml.LanguageServiceDefaults): voi
     createDocumentFormattingEditProvider(worker),
   );
   languages.registerLinkProvider(languageId, createLinkProvider(worker));
+  languages.registerCodeActionProvider(languageId, createCodeActionProvider(worker));
   createDiagnosticsAdapter(worker, defaults);
   languages.setLanguageConfiguration(languageId, richEditConfiguration);
 }

src/yamlWorker.ts

@@ -34,6 +34,12 @@ export interface YAMLWorker {
   findDocumentSymbols: (uri: string) => Promisable<ls.DocumentSymbol[]>;
 
   findLinks: (uri: string) => Promisable<ls.DocumentLink[]>;
+
+  getCodeAction: (
+    uri: string,
+    range: ls.Range,
+    diagnostics: ls.Diagnostic[],
+  ) => Promisable<ls.CodeAction[]>;
 }
 
 export function createYAMLWorker(
@@ -101,6 +107,15 @@ export function createYAMLWorker(
       const document = getTextDocument(uri);
       return languageService.findLinks(document);
     },
+
+    getCodeAction(uri, range, diagnostics) {
+      const document = getTextDocument(uri);
+      return languageService.getCodeAction(document, {
+        range,
+        textDocument: { uri },
+        context: { diagnostics },
+      });
+    },
   };
 }