Testing

@adecore/editor-react/testing holds a fake language service and a manual clock, so the features run in bun test without a server, a process or a browser.

FakeLanguageService

FakeLanguageService implements LanguageService in memory. respond(method, answer, provider?) registers an answer for an LSP method and the provider options the service declares for it, such as triggerCharacters. A method without an answer is unsupported and rejects with code -32601.

import { expect, test } from 'bun:test';
import { FakeEditorEngine } from '@adecore/editor/fake';
import { EditorLanguage, ProjectLanguage } from '@adecore/editor-react';
import { FakeLanguageService, ManualTimers } from '@adecore/editor-react/testing';

test('the editor reports its edits and counts problems', async () => {
    const service = new FakeLanguageService();
    const project = new ProjectLanguage(service);
    const editor = new FakeEditorEngine().mount({} as HTMLElement, { text: 'one', theme: 'light' });
    const language = new EditorLanguage(project, editor, 'file:///work/example.ts', 'typescript', new ManualTimers());

    await language.document.ready;
    editor.type('two');
    expect(service.documents.get(language.uri)?.text).toBe('two');

    service.report({
        uri: language.uri,
        source: 'fake',
        diagnostics: [{ range: { start: { line: 0, character: 0 }, end: { line: 0, character: 3 } }, message: 'A problem', severity: 1 }]
    });
    expect(language.diagnostics.counts().error).toBe(1);

    language.dispose();
    project.dispose();
});

Member	What it is
documents	The open documents with their text and version
calls	Every request and document notification, as LanguageCalls (method, uri, params, options)
report(report)	Sends a diagnostics report
refresh(uri)	Fires onProvidersChanged, as a server that came up
respond('open', answer)	Runs when a document opens; an answer that returns a promise delays the open

An answer for a document whose text changed while it was pending rejects with StaleResultError, as a real service must. The fake does not model several clients of one document or a server that fails; for those, test the LSP layer.

ManualTimers

The features wait before they ask: 80 milliseconds before suggestions, 300 before a hover card. ManualTimers replaces the clock, passed as the last argument of EditorLanguage. advance(ms) runs what is due, and the test awaits the promises of the requests that started.