VS Code: move DocumentLinter into lower-level module

I want to test DocumentLinter more directly. Discourage DocumentLinter
depending on VS Code by moving it into the wasm/ directory.

Replace uses of Node.js' assert module to make the code web-compatible.

This commit should not change behavior.

Author: strager

plugin/vscode/extension.js

@@ -3,294 +3,16 @@
 
 "use strict";
 
-let assert = require("assert");
 let vscode = require("vscode");
 let {
   DiagnosticSeverity,
-  ProcessCrashed,
+  DocumentLinter,
   createProcessFactoryAsync,
 } = require("quick-lint-js-wasm/quick-lint-js.js");
 
 // TODO(strager): Allow developers to reload the .wasm file.
 let processFactoryPromise = createProcessFactoryAsync();
 
-let DocumentLinterState = {
-  // A DocumentForVSCode hasn't been created yet.
-  NO_PARSER: "NO_PARSER",
-
-  // A DocumentForVSCode is in the process of being created.
-  CREATING_PARSER: "CREATING_PARSER",
-
-  // A DocumentForVSCode has been created, but it has no text.
-  PARSER_UNINITIALIZED: "PARSER_UNINITIALIZED",
-
-  // A DocumentForVSCode has been created, and its text is up-to-date with the
-  // vscode.Document.
-  PARSER_LOADED: "PARSER_LOADED",
-
-  // The DocumentForVSCode's Process crashed, and we are creating a new Process
-  // and DocumentForVSCode.
-  //
-  // Document changes should be queued.
-  RECOVERING: "RECOVERING",
-
-  DISPOSED: "DISPOSED",
-};
-
-class LintingCrashed extends Error {
-  constructor(originalError) {
-    super(String(originalError));
-    this.originalError = originalError;
-  }
-}
-exports.LintingCrashed = LintingCrashed;
-
-class DocumentLinterDisposed extends Error {}
-exports.DocumentLinterDisposed = DocumentLinterDisposed;
-
-class DocumentLinter {
-  // document has the following methods:
-  //
-  //   getText(): string;
-  //   setDiagnostics(diagnostics: Object[]): void;
-  //   removeDiagnostics(): void;
-  constructor(document, processFactoryPromise) {
-    this._document = document;
-    this._processFactoryPromise = processFactoryPromise;
-    this._state = DocumentLinterState.NO_PARSER;
-
-    // Used only in states: CREATING_PARSER
-    this._parserPromise = null;
-
-    // Used only in states: PARSER_UNINITIALIZED, PARSER_LOADED
-    this._parser = null;
-
-    // Used only in states: PARSER_LOADED, RECOVERING
-    this._pendingChanges = [];
-
-    // Used only in states: RECOVERING
-    this._recoveryPromise = null;
-  }
-
-  async _createParser() {
-    assert.strictEqual(this._state, DocumentLinterState.NO_PARSER);
-    this._state = DocumentLinterState.CREATING_PARSER;
-    this._parserPromise = (async () => {
-      let factory = await this._processFactoryPromise;
-      // TODO(strager): Reuse processes across documents.
-      let process = await factory.createProcessAsync();
-      let parser = await process.createDocumentForVSCodeAsync();
-
-      if (this._state === DocumentLinterState.DISPOSED) {
-        parser.dispose();
-        throw new DocumentLinterDisposed();
-      }
-      assert.strictEqual(this._state, DocumentLinterState.CREATING_PARSER);
-      this._parser = parser;
-      this._state = DocumentLinterState.PARSER_UNINITIALIZED;
-      return parser;
-    })();
-    return await this._parserPromise;
-  }
-
-  async disposeAsync() {
-    let oldState = this._state;
-    this._state = DocumentLinterState.DISPOSED;
-    switch (oldState) {
-      case DocumentLinterState.NO_PARSER:
-        break;
-
-      case DocumentLinterState.CREATING_PARSER:
-      case DocumentLinterState.PARSER_UNINITIALIZED:
-      case DocumentLinterState.PARSER_LOADED: {
-        try {
-          await this._parserPromise;
-        } catch (e) {
-          if (!(e instanceof DocumentLinterDisposed)) {
-            throw e;
-          }
-        }
-        if (this._parser !== null) {
-          this._parser.dispose();
-        }
-        break;
-      }
-
-      case DocumentLinterState.DISPOSED:
-        // TODO(strager): Should double-dispose be okay?
-        throw new DocumentLinterDisposed();
-
-      default:
-        throw new Error(`Unexpected linter state: ${this._state}`);
-    }
-    this._document.removeDiagnostics();
-  }
-
-  dispose() {
-    logAsyncErrors(async () => {
-      await this.disposeAsync();
-    });
-  }
-
-  async editorChangedVisibilityAsync() {
-    switch (this._state) {
-      case DocumentLinterState.NO_PARSER:
-        await this._createParser();
-        await this.editorChangedVisibilityAsync();
-        break;
-
-      case DocumentLinterState.CREATING_PARSER:
-        await this._parserPromise;
-        await this.editorChangedVisibilityAsync();
-        break;
-
-      case DocumentLinterState.PARSER_UNINITIALIZED:
-        await this._initializeParserAsync();
-        break;
-
-      case DocumentLinterState.PARSER_LOADED:
-        // No changes could have been made with the editor closed. Ignore.
-        break;
-
-      case DocumentLinterState.DISPOSED:
-        throw new DocumentLinterDisposed();
-
-      default:
-        throw new Error(`Unexpected linter state: ${this._state}`);
-    }
-  }
-
-  async textChangedAsync(changes) {
-    // BEGIN CRITICAL SECTION (no awaiting below)
-    switch (this._state) {
-      case DocumentLinterState.NO_PARSER:
-        // END CRITICAL SECTION (no awaiting above)
-        await this._createParser();
-        await this._initializeParserAsync();
-        break;
-
-      case DocumentLinterState.CREATING_PARSER:
-        // END CRITICAL SECTION (no awaiting above)
-        await this._parserPromise;
-        await this._initializeParserAsync();
-        break;
-
-      case DocumentLinterState.PARSER_UNINITIALIZED:
-        // END CRITICAL SECTION (no awaiting above)
-        await this._initializeParserAsync();
-        break;
-
-      case DocumentLinterState.PARSER_LOADED:
-        this._pendingChanges.push(...changes);
-        try {
-          for (let change of this._pendingChanges) {
-            this._parser.replaceText(change.range, change.text);
-          }
-          this._pendingChanges.length = 0;
-          // END CRITICAL SECTION (no awaiting above)
-
-          let diags = this._parser.lint();
-          this._document.setDiagnostics(diags);
-        } catch (e) {
-          // END CRITICAL SECTION (no awaiting above)
-          if (e instanceof ProcessCrashed) {
-            await this._recoverFromCrashAsync(e);
-          } else {
-            throw e;
-          }
-        }
-        break;
-
-      case DocumentLinterState.RECOVERING:
-        this._pendingChanges.push(...changes);
-        // END CRITICAL SECTION (no awaiting above)
-        await this._recoveryPromise;
-        // Changes should have been applied during recovery.
-        assert.strictEqual(this._pendingChanges.includes(changes[0]), false);
-        break;
-
-      case DocumentLinterState.DISPOSED:
-        throw new DocumentLinterDisposed();
-
-      default:
-        throw new Error(`Unexpected linter state: ${this._state}`);
-    }
-  }
-
-  // Transition: PARSER_UNINITIALIZED -> PARSER_LOADED (or NO_PARSER on error)
-  async _initializeParserAsync() {
-    // BEGIN CRITICAL SECTION (no awaiting below)
-    assert.strictEqual(this._state, DocumentLinterState.PARSER_UNINITIALIZED);
-    try {
-      this._parser.replaceText(
-        {
-          start: { line: 0, character: 0 },
-          end: { line: 0, character: 0 },
-        },
-        this._document.getText()
-      );
-      this._pendingChanges.length = 0;
-      this._state = DocumentLinterState.PARSER_LOADED;
-      // END CRITICAL SECTION (no awaiting above)
-
-      let diags = this._parser.lint();
-      this._document.setDiagnostics(diags);
-    } catch (e) {
-      if (e instanceof ProcessCrashed) {
-        await this._recoverFromCrashAsync(e);
-      } else {
-        throw e;
-      }
-    }
-  }
-
-  // Transition: any -> RECOVERING -> PARSER_LOADED (or NO_PARSER on error)
-  async _recoverFromCrashAsync(error) {
-    // BEGIN CRITICAL SECTION (no awaiting below)
-    console.warn(
-      `[quick-lint-js] warning: Parser process crashed. Recovering: ${error.stack}`
-    );
-    this._state = DocumentLinterState.RECOVERING;
-    this._recoveryPromise = (async () => {
-      let diags;
-      try {
-        // TODO(strager): Reuse processes across documents.
-        let factory = await this._processFactoryPromise;
-        let process = await factory.createProcessAsync();
-        let parser = await process.createDocumentForVSCodeAsync();
-
-        // BEGIN CRITICAL SECTION (no awaiting below)
-        assert.strictEqual(this._state, DocumentLinterState.RECOVERING);
-        parser.replaceText(
-          {
-            start: { line: 0, character: 0 },
-            end: { line: 0, character: 0 },
-          },
-          this._document.getText()
-        );
-        this._pendingChanges.length = 0;
-        this._parser = parser;
-        this._state = DocumentLinterState.PARSER_LOADED;
-        // END CRITICAL SECTION (no awaiting above)
-
-        diags = parser.lint();
-      } catch (e) {
-        this._parser = null;
-        this._parserPromise = null;
-        this._state = DocumentLinterState.NO_PARSER;
-        if (e instanceof ProcessCrashed) {
-          throw new LintingCrashed(e);
-        } else {
-          throw e;
-        }
-      }
-      this._document.setDiagnostics(diags);
-    })();
-    // END CRITICAL SECTION (no awaiting above)
-    await this._recoveryPromise;
-  }
-}
-
 class VSCodeDocumentLinter {
   constructor(document, diagnosticCollection) {
     this._documentLinter = new DocumentLinter(

plugin/vscode/test/other-tests.js

@@ -196,7 +196,7 @@ let tests = {
 
     // Should not throw.
     await linter.disposeAsync();
-    await assert.rejects(promise, extension.DocumentLinterDisposed);
+    await assert.rejects(promise, qljs.DocumentLinterDisposed);
   },
 
   "concurrent edits are applied in order of calls": async ({ addCleanup }) => {
@@ -344,7 +344,7 @@ let tests = {
         await callback();
         return false;
       } catch (e) {
-        if (e instanceof extension.LintingCrashed) {
+        if (e instanceof qljs.LintingCrashed) {
           return true;
         } else {
           throw e;