Diffusion Ant (type-hints-typescript) Code

ant/examples/spec/diagnostics_channel.js
899dad6b8a9etype-hints-typescript

diagnostics_channel.js
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			import { test, testThrows, testDeep, summary } from './helpers.js';
			import diagnosticsChannel from 'node:diagnostics_channel';

			console.log('diagnostics_channel\n');

			function collectEvents(tracing) {
			const events = [];

			for (const name of ['start', 'end', 'asyncStart', 'asyncEnd', 'error']) {
			tracing[name].subscribe(message => {
			events.push({ name, message: { ...message } });
			});
			}

			return events;
			}

			test('exports channel', typeof diagnosticsChannel.channel, 'function');
			test('exports tracingChannel', typeof diagnosticsChannel.tracingChannel, 'function');

			const symbolName = Symbol('diagnostics');
			test(
			'channel caches string names',
			diagnosticsChannel.channel('spec:diagnostics:string') === diagnosticsChannel.channel('spec:diagnostics:string'),
			true
			);
			test('channel accepts symbol names', diagnosticsChannel.channel(symbolName).name, symbolName);

			testThrows('channel rejects invalid names', () => diagnosticsChannel.channel(123));
			testThrows('subscribe rejects non-functions', () => diagnosticsChannel.channel('spec:diagnostics:invalid-subscription').subscribe(123));

			const storeChannel = diagnosticsChannel.channel('spec:diagnostics:store');
			const store = {
			run(_value, fn) {
			return fn();
			}
			};
			test('hasSubscribers starts false', storeChannel.hasSubscribers, false);
			storeChannel.bindStore(store);
			test('bindStore contributes to hasSubscribers', storeChannel.hasSubscribers, true);
			storeChannel.unbindStore(store);
			test('unbindStore clears hasSubscribers', storeChannel.hasSubscribers, false);

			const snapshotChannel = diagnosticsChannel.channel('spec:diagnostics:snapshot');
			const snapshotCalls = [];
			const lateSubscriber = () => snapshotCalls.push('late');
			snapshotChannel.subscribe(() => {
			snapshotCalls.push('first');
			snapshotChannel.subscribe(lateSubscriber);
			});
			snapshotChannel.subscribe(() => snapshotCalls.push('second'));
			snapshotChannel.publish({});
			snapshotChannel.publish({});
			testDeep('publish snapshots subscribers', snapshotCalls, ['first', 'second', 'first', 'second', 'late']);

			const syncTracing = diagnosticsChannel.tracingChannel('spec:diagnostics:sync');
			const syncEvents = collectEvents(syncTracing);
			test(
			'traceSync returns result',
			syncTracing.traceSync(() => 42, { phase: 'sync' }),
			42
			);
			testDeep('traceSync publishes start/end', syncEvents, [
			{ name: 'start', message: { phase: 'sync' } },
			{ name: 'end', message: { phase: 'sync', result: 42 } }
			]);

			const promiseTracing = diagnosticsChannel.tracingChannel('spec:diagnostics:promise');
			const promiseEvents = collectEvents(promiseTracing);
			test('tracePromise resolves result', await promiseTracing.tracePromise(() => Promise.resolve(7), { phase: 'promise' }), 7);
			testDeep('tracePromise publishes end before async events', promiseEvents, [
			{ name: 'start', message: { phase: 'promise' } },
			{ name: 'end', message: { phase: 'promise' } },
			{ name: 'asyncStart', message: { phase: 'promise', result: 7 } },
			{ name: 'asyncEnd', message: { phase: 'promise', result: 7 } }
			]);

			const callbackTracing = diagnosticsChannel.tracingChannel('spec:diagnostics:callback');
			const callbackEvents = collectEvents(callbackTracing);
			let callbackError = '';
			const callbackReturn = callbackTracing.traceCallback(
			callback => {
			try {
			callback(null, 9);
			} catch (err) {
			callbackError = err.message;
			}
			return 'outer-result';
			},
			-1,
			{ phase: 'callback' },
			undefined,
			() => {
			throw new Error('callback boom');
			}
			);
			test('traceCallback returns outer result', callbackReturn, 'outer-result');
			test('traceCallback uses the last argument by default', callbackError, 'callback boom');
			testDeep('traceCallback still publishes asyncEnd when callback throws', callbackEvents, [
			{ name: 'start', message: { phase: 'callback' } },
			{ name: 'asyncStart', message: { phase: 'callback', result: 9 } },
			{ name: 'asyncEnd', message: { phase: 'callback', result: 9 } },
			{ name: 'end', message: { phase: 'callback', result: 9 } }
			]);

			summary();

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