Add on type formatting provider

packages/core/src/common/index.ts

@@ -1,2 +1,3 @@
 export type { Position } from './position';
 export type { Range } from './range';
+export type { TextEdit } from './text-edit';

packages/core/src/common/text-edit.ts

@@ -0,0 +1,6 @@
+import { Range } from './range';
+
+export interface TextEdit {
+  range: Range;
+  newText: string;
+}

packages/core/src/formatting/index.ts

@@ -0,0 +1 @@
+export type { OnTypeFormattingProvider, OnTypeFormattingProviderFactory } from './on-type-formatting-provider';

packages/core/src/formatting/on-type-formatting-provider.ts

@@ -0,0 +1,16 @@
+import { Position } from '../common/position';
+import { TextEdit } from '../common/text-edit';
+import { Document } from '../document/document';
+import { DocumentManager } from '../document/document-manager';
+
+export type OnTypeFormattingProviderFactory<T extends Document> = (
+  DocumentManager: DocumentManager<T>,
+) => OnTypeFormattingProvider;
+
+export interface OnTypeFormattingProvider {
+  readonly id: string;
+
+  readonly onTypeTriggerCharacters: ReadonlySet<string>;
+
+  getOnTypeEdits(uri: string, position: Position, ch: string): Promise<TextEdit[] | undefined>;
+}

packages/core/src/index.ts

@@ -1,4 +1,5 @@
 export * from './common';
 export * from './diagnostic';
 export * from './document';
+export * from './formatting';
 export * from './workspace';

packages/core/src/workspace/workspace.ts

@@ -1,21 +1,26 @@
 import { map, merge, Observable, tap } from 'rxjs';
 
+import { Position } from '../common/position';
+import { TextEdit } from '../common/text-edit';
 import { Diagnostic } from '../diagnostic/diagnostic';
 import { DiagnosticFix } from '../diagnostic/diagnostic-fix';
 import { DiagnosticProvider, DiagnosticProviderFactory, DiagnosticsChanged } from '../diagnostic/diagnostic-provider';
 import { Document } from '../document/document';
 import { DocumentFactory } from '../document/document-factory';
 import { DocumentManager } from '../document/document-manager';
 import { DocumentReader } from '../document/document-reader';
+import { OnTypeFormattingProvider, OnTypeFormattingProviderFactory } from '../formatting/on-type-formatting-provider';
 
 export interface WorkspaceConfig<T extends Document> {
   documentReader?: DocumentReader;
   documentFactory: DocumentFactory<T>;
-  diagnosticProviders: DiagnosticProviderFactory<T>[];
+  diagnosticProviders?: DiagnosticProviderFactory<T>[];
+  onTypeFormattingProviders?: OnTypeFormattingProviderFactory<T>[];
 }
 
 export class Workspace<T extends Document> {
   private readonly diagnosticProviders: Map<string, DiagnosticProvider>;
+  private readonly onTypeFormattingProviders: Map<string, OnTypeFormattingProvider>;
   private readonly lastDiagnosticChangedEvents = new Map<string, DiagnosticsChanged[]>();
 
   public readonly documentManager: DocumentManager<T>;
@@ -24,7 +29,7 @@ export class Workspace<T extends Document> {
   constructor(config: WorkspaceConfig<T>) {
     this.documentManager = new DocumentManager(config.documentReader, config.documentFactory);
     this.diagnosticProviders = new Map(
-      config.diagnosticProviders.map((factory) => {
+      config.diagnosticProviders?.map((factory) => {
         const provider = factory(this.documentManager);
         return [provider.id, provider];
       }),
@@ -38,6 +43,12 @@ export class Workspace<T extends Document> {
         ),
       ),
     ).pipe(map((e) => this.getCombinedDiagnosticChangedEvent(e.uri, e.version)));
+    this.onTypeFormattingProviders = new Map(
+      config.onTypeFormattingProviders?.map((factory) => {
+        const provider = factory(this.documentManager);
+        return [provider.id, provider];
+      }),
+    );
   }
 
   async getDiagnostics(uri: string): Promise<Diagnostic[]> {
@@ -56,6 +67,28 @@ export class Workspace<T extends Document> {
     return await provider.getDiagnosticFixes(uri, diagnostic);
   }
 
+  getOnTypeTriggerCharacters(): string[] {
+    const characters = new Set<string>();
+    for (const provider of this.onTypeFormattingProviders.values()) {
+      for (const ch of provider.onTypeTriggerCharacters) {
+        characters.add(ch);
+      }
+    }
+    return Array.from(characters);
+  }
+
+  async getOnTypeEdits(uri: string, position: Position, ch: string): Promise<TextEdit[] | undefined> {
+    for (const provider of this.onTypeFormattingProviders.values()) {
+      if (provider.onTypeTriggerCharacters.has(ch)) {
+        const edits = await provider.getOnTypeEdits(uri, position, ch);
+        if (edits != null) {
+          return edits;
+        }
+      }
+    }
+    return undefined;
+  }
+
   private updateCombinedDiagnosticChangedEvent(providerIndex: number, event: DiagnosticsChanged) {
     const docEvents = this.lastDiagnosticChangedEvents.get(event.uri) ?? [];
     docEvents[providerIndex] = event;

packages/eslint-config/library.mjs

@@ -32,6 +32,7 @@ export default tseslint.config(
       ],
       '@typescript-eslint/no-non-null-assertion': 'off',
       '@typescript-eslint/no-unsafe-call': 'off',
+      '@typescript-eslint/no-unsafe-assignment': 'off',
     },
   },
   {

packages/vscode/src/server.ts

@@ -52,6 +52,13 @@ connection.onInitialize((params: InitializeParams) => {
       codeActionProvider: true,
     },
   };
+  const onTypeTriggerCharacters = workspace.getOnTypeTriggerCharacters();
+  if (onTypeTriggerCharacters.length > 0) {
+    result.capabilities.documentOnTypeFormattingProvider = {
+      firstTriggerCharacter: onTypeTriggerCharacters[0],
+      moreTriggerCharacter: onTypeTriggerCharacters.slice(1),
+    };
+  }
   if (hasWorkspaceFolderCapability) {
     result.capabilities.workspace = {
       workspaceFolders: {
@@ -130,6 +137,10 @@ connection.onDidChangeTextDocument((params) => {
   );
 });
 
+connection.onDocumentOnTypeFormatting(async (params) => {
+  return await workspace.getOnTypeEdits(params.textDocument.uri, params.position, params.ch);
+});
+
 connection.onDidChangeWatchedFiles((_change) => {
   // Monitored files have change in VSCode
   connection.console.log('We received a file change event');