Change the build system to not be stream based.

src/internal/build.ts

@@ -6,16 +6,13 @@
 
 import {Deferred} from '../shared/deferred.js';
 
-import {
-  SampleFile,
-  BuildOutput,
-  FileBuildOutput,
-  DiagnosticBuildOutput,
+import type {
+  File,
+  FileDiagnostic,
+  Diagnostic,
   HttpError,
+  BuildResult,
 } from '../shared/worker-api.js';
-import {Diagnostic} from 'vscode-languageserver-protocol';
-
-const unreachable = (n: never) => n;
 
 type State = 'active' | 'done' | 'cancelled';
 
@@ -36,15 +33,15 @@ export class PlaygroundBuild {
   diagnostics = new Map<string, Diagnostic[]>();
   private _state: State = 'active';
   private _stateChange = new Deferred<void>();
-  private _files = new Map<string, Deferred<SampleFile | HttpError>>();
+  private _files = new Map<string, Deferred<File | HttpError>>();
   private _diagnosticsCallback: () => void;
   private _diagnosticsDebounceId: number | undefined;
 
   /**
    * @param diagnosticsCallback Function that will be invoked when one or more
    * new diagnostics have been received. Fires at most once per animation frame.
    */
-  constructor(diagnosticsCallback: () => void) {
+  constructor({diagnosticsCallback}: {diagnosticsCallback: () => void}) {
     this._diagnosticsCallback = diagnosticsCallback;
   }
 
@@ -79,10 +76,14 @@ export class PlaygroundBuild {
    * received before the build is completed or cancelled, this promise will be
    * rejected.
    */
-  async getFile(name: string): Promise<SampleFile | HttpError> {
+  async getFile(name: string): Promise<File | HttpError> {
     let deferred = this._files.get(name);
     if (deferred === undefined) {
       if (this._state === 'done') {
+        // TODO (justinfagnani): If the file is a package dependency (in
+        // 'node_modules/'), get the file from the TypeScript worker here
+        // rather than assuming that it is present in the files cache.
+        // Let the worker handle the error if the file is not found.
         return errorNotFound;
       } else if (this._state === 'cancelled') {
         return errorCancelled;
@@ -94,24 +95,25 @@ export class PlaygroundBuild {
   }
 
   /**
-   * Handle a worker build output.
+   * Handle a worker build result.
    */
-  onOutput(output: BuildOutput) {
+  onResult(output: BuildResult) {
     if (this._state !== 'active') {
       return;
     }
-    if (output.kind === 'file') {
-      this._onFile(output);
-    } else if (output.kind === 'diagnostic') {
-      this._onDiagnostic(output);
-    } else if (output.kind === 'done') {
-      this._onDone();
-    } else {
-      throw new Error(
-        `Unexpected BuildOutput kind: ${
-          (unreachable(output) as BuildOutput).kind
-        }`
-      );
+    for (const file of output.files) {
+      this._onFile(file);
+    }
+    for (const fileDiagnostic of output.diagnostics) {
+      this._onDiagnostic(fileDiagnostic);
+    }
+  }
+
+  onSemanticDiagnostics(semanticDiagnostics?: Array<FileDiagnostic>) {
+    if (semanticDiagnostics !== undefined) {
+      for (const fileDiagnostic of semanticDiagnostics) {
+        this._onDiagnostic(fileDiagnostic);
+      }
     }
   }
 
@@ -121,22 +123,22 @@ export class PlaygroundBuild {
     this._stateChange = new Deferred();
   }
 
-  private _onFile(output: FileBuildOutput) {
-    let deferred = this._files.get(output.file.name);
+  private _onFile(file: File) {
+    let deferred = this._files.get(file.name);
     if (deferred === undefined) {
       deferred = new Deferred();
-      this._files.set(output.file.name, deferred);
+      this._files.set(file.name, deferred);
     }
-    deferred.resolve(output.file);
+    deferred.resolve(file);
   }
 
-  private _onDiagnostic(output: DiagnosticBuildOutput) {
-    let arr = this.diagnostics.get(output.filename);
+  private _onDiagnostic(fileDiagnostic: FileDiagnostic) {
+    let arr = this.diagnostics.get(fileDiagnostic.filename);
     if (arr === undefined) {
       arr = [];
-      this.diagnostics.set(output.filename, arr);
+      this.diagnostics.set(fileDiagnostic.filename, arr);
     }
-    arr.push(output.diagnostic);
+    arr.push(fileDiagnostic.diagnostic);
     if (this._diagnosticsDebounceId === undefined) {
       this._diagnosticsDebounceId = requestAnimationFrame(() => {
         if (this._state !== 'cancelled') {
@@ -147,7 +149,13 @@ export class PlaygroundBuild {
     }
   }
 
-  private _onDone() {
+  /**
+   * Completes a build. Must be called after onResult() and
+   * onSemanticDiagnostics().
+   *
+   * TODO (justinfagnani): do this automatically?
+   */
+  onDone() {
     this._errorPendingFileRequests(errorNotFound);
     this._changeState('done');
   }

src/playground-code-editor.ts

@@ -19,7 +19,6 @@ import {ifDefined} from 'lit/directives/if-defined.js';
 import {CodeMirror} from './internal/codemirror.js';
 import playgroundStyles from './playground-styles.js';
 import './internal/overlay.js';
-import {Diagnostic} from 'vscode-languageserver-protocol';
 import {
   Doc,
   Editor,
@@ -35,6 +34,7 @@ import {
   EditorPosition,
   EditorToken,
   CodeEditorChangeData,
+  type Diagnostic,
 } from './shared/worker-api.js';
 
 // TODO(aomarks) Could we upstream this to lit-element? It adds much stricter

src/playground-project.ts

@@ -9,19 +9,21 @@ import {customElement, property, query, state} from 'lit/decorators.js';
 import {wrap, Remote, proxy} from 'comlink';
 
 import {
-  SampleFile,
-  ServiceWorkerAPI,
-  ProjectManifest,
-  PlaygroundMessage,
-  WorkerAPI,
+  type SampleFile,
+  type ServiceWorkerAPI,
+  type ProjectManifest,
+  type PlaygroundMessage,
+  type WorkerAPI,
   CONFIGURE_PROXY,
   CONNECT_PROJECT_TO_SW,
   ACKNOWLEDGE_SW_CONNECTION,
-  ModuleImportMap,
-  HttpError,
+  type ModuleImportMap,
+  type HttpError,
   UPDATE_SERVICE_WORKER,
-  CodeEditorChangeData,
-  CompletionInfoWithDetails,
+  type CodeEditorChangeData,
+  type CompletionInfoWithDetails,
+  type Diagnostic,
+  FileDiagnostic,
 } from './shared/worker-api.js';
 import {
   getRandomString,
@@ -37,8 +39,6 @@ import {npmVersion, serviceWorkerHash} from './shared/version.js';
 import {Deferred} from './shared/deferred.js';
 import {PlaygroundBuild} from './internal/build.js';
 
-import {Diagnostic} from 'vscode-languageserver-protocol';
-
 // Each <playground-project> has a unique session ID used to scope requests from
 // the preview iframes.
 const sessions = new Set<string>();
@@ -559,26 +559,30 @@ export class PlaygroundProject extends LitElement {
    */
   async save() {
     this._build?.cancel();
-    const build = new PlaygroundBuild(() => {
-      this.dispatchEvent(new CustomEvent('diagnosticsChanged'));
-    });
-    this._build = build;
-    this.dispatchEvent(new CustomEvent('compileStart'));
     const workerApi = await this._deferredTypeScriptWorkerApi.promise;
+    const build = (this._build = new PlaygroundBuild({
+      diagnosticsCallback: () => {
+        this.dispatchEvent(new CustomEvent('diagnosticsChanged'));
+      },
+    }));
+    this.dispatchEvent(new CustomEvent('compileStart'));
     if (build.state() !== 'active') {
       return;
     }
-    /* eslint-disable @typescript-eslint/no-floating-promises */
-    workerApi.compileProject(
+    const receivedSemanticDiagnostics = new Deferred<void>();
+    const result = await workerApi.compileProject(
       this._files ?? [],
-      {importMap: this._importMap},
-      proxy((result) => build.onOutput(result))
+      {
+        importMap: this._importMap,
+      },
+      proxy((diagnostics?: Array<FileDiagnostic>) => {
+        build.onSemanticDiagnostics(diagnostics);
+        receivedSemanticDiagnostics.resolve();
+      })
     );
-    /* eslint-enable @typescript-eslint/no-floating-promises */
-    await build.stateChange;
-    if (build.state() !== 'done') {
-      return;
-    }
+    build.onResult(result);
+    await receivedSemanticDiagnostics.promise;
+    build.onDone();
     this.dispatchEvent(new CustomEvent('compileDone'));
   }
 

src/shared/worker-api.ts

@@ -5,7 +5,8 @@
  */
 
 import {CompletionEntry, CompletionInfo, WithMetadata} from 'typescript';
-import {Diagnostic} from 'vscode-languageserver-protocol';
+import type {Diagnostic} from 'vscode-languageserver-protocol';
+export type {Diagnostic} from 'vscode-languageserver-protocol';
 
 /**
  * Sent from the project to the proxy, with configuration and a port for further
@@ -123,10 +124,10 @@ export interface EditorCompletionDetails {
 
 export interface WorkerAPI {
   compileProject(
-    files: Array<SampleFile>,
+    files: Array<File>,
     config: WorkerConfig,
-    emit: (result: BuildOutput) => void
-  ): Promise<void>;
+    onSemanticDiagnostics?: (diagnostics?: Array<FileDiagnostic>) => void
+  ): Promise<BuildResult>;
   getCompletions(
     filename: string,
     fileContent: string,
@@ -142,6 +143,15 @@ export interface WorkerAPI {
   ): Promise<EditorCompletionDetails>;
 }
 
+export interface File {
+  /** Filename. */
+  name: string;
+  /** File contents. */
+  content: string;
+  /** MIME type. */
+  contentType?: string;
+}
+
 export interface HttpError {
   status: number;
   body: string;
@@ -151,15 +161,9 @@ export interface FileAPI {
   getFile(name: string): Promise<SampleFile | HttpError>;
 }
 
-export interface SampleFile {
-  /** Filename. */
-  name: string;
+export interface SampleFile extends File {
   /** Optional display label. */
   label?: string;
-  /** File contents. */
-  content: string;
-  /** MIME type. */
-  contentType?: string;
   /** Don't display in tab bar. */
   hidden?: boolean;
   /** Whether the file should be selected when loaded */
@@ -213,19 +217,35 @@ export interface CompletionInfoWithDetails
   entries: CompletionEntryWithDetails[];
 }
 
-export type BuildOutput = FileBuildOutput | DiagnosticBuildOutput | DoneOutput;
-
-export type FileBuildOutput = {
-  kind: 'file';
-  file: SampleFile;
-};
-
-export type DiagnosticBuildOutput = {
-  kind: 'diagnostic';
+export interface FileDiagnostic {
   filename: string;
   diagnostic: Diagnostic;
-};
+}
 
-export type DoneOutput = {
-  kind: 'done';
-};
+export interface BuildResult {
+  files: Array<File>;
+  diagnostics: Array<FileDiagnostic>;
+  semanticDiagnostics?: Promise<Array<FileDiagnostic>>;
+}
+
+export interface FileResult {
+  file?: File;
+  diagnostics: Array<Diagnostic>;
+}
+
+// export type BuildOutput = FileBuildOutput | DiagnosticBuildOutput | DoneOutput;
+
+// export type FileBuildOutput = {
+//   kind: 'file';
+//   file: SampleFile;
+// };
+
+// export type DiagnosticBuildOutput = {
+//   kind: 'diagnostic';
+//   filename: string;
+//   diagnostic: Diagnostic;
+// };
+
+// export type DoneOutput = {
+//   kind: 'done';
+// };