Close #330 PR: use empower-core for better assertion tracking and performance.

Author: jamestalmage

api.js

@@ -9,6 +9,7 @@ var figures = require('figures');
 var globby = require('globby');
 var chalk = require('chalk');
 var fork = require('./lib/fork');
+var formatter = require('./lib/enhance-assert').formatter();
 
 function Api(files, options) {
 	if (!(this instanceof Api)) {
@@ -76,6 +77,13 @@ Api.prototype._handleTest = function (test) {
 	var isError = test.error.message;
 
 	if (isError) {
+		if (test.error.powerAssertContext) {
+			var message = formatter(test.error.powerAssertContext);
+			if (test.error.originalMessage) {
+				message = test.error.originalMessage + ' ' + message;
+			}
+			test.error.message = message;
+		}
 		this.errors.push(test);
 	} else {
 		test.error = null;

lib/assert.js

@@ -120,5 +120,3 @@ x.regexTest = function (regex, contents, msg) {
 x.ifError = x.error = function (err, msg) {
 	test(!err, create(err, 'Error', '!==', msg, x.ifError));
 };
-
-require('./enhance-assert')(x);

lib/enhance-assert.js

@@ -1,4 +1,5 @@
 module.exports = enhanceAssert;
+module.exports.formatter = formatter;
 
 module.exports.PATTERNS = [
 	't.ok(value, [message])',
@@ -12,23 +13,40 @@ module.exports.PATTERNS = [
 	't.regexTest(regex, contents, [message])'
 ];
 
-function enhanceAssert(assert) {
-	var empower = require('empower');
-	var powerAssertFormatter = require('power-assert-formatter');
-	var powerAssertRenderers = require('power-assert-renderers');
+module.exports.NON_ENHANCED_PATTERNS = [
+	't.pass([message])',
+	't.fail([message])',
+	't.throws(fn, [message])',
+	't.doesNotThrow(fn, [message])',
+	't.ifError(error, [message])'
+];
 
-	empower(assert,
-		powerAssertFormatter({
-			renderers: [
-				powerAssertRenderers.AssertionRenderer,
-				powerAssertRenderers.SuccinctRenderer
-			]
-		}),
+function enhanceAssert(opts) {
+	var empower = require('empower-core');
+	var enhanced = empower(
+		opts.assert,
 		{
-			destructive: true,
-			modifyMessageOnRethrow: true,
-			saveContextOnRethrow: false,
-			patterns: module.exports.PATTERNS
+			destructive: false,
+			onError: opts.onError,
+			onSuccess: opts.onSuccess,
+			patterns: module.exports.PATTERNS,
+			wrapOnlyPatterns: module.exports.NON_ENHANCED_PATTERNS
 		}
 	);
+
+	enhanced.AssertionError = opts.assert.AssertionError;
+
+	return enhanced;
+}
+
+function formatter() {
+	var powerAssertFormatter = require('power-assert-formatter');
+	var powerAssertRenderers = require('power-assert-renderers');
+
+	return powerAssertFormatter({
+		renderers: [
+			powerAssertRenderers.AssertionRenderer,
+			powerAssertRenderers.SuccinctRenderer
+		]
+	});
 }

lib/test.js

@@ -8,6 +8,7 @@ var observableToPromise = require('observable-to-promise');
 var isPromise = require('is-promise');
 var isObservable = require('is-observable');
 var assert = require('./assert');
+var enhanceAssert = require('./enhance-assert');
 var globals = require('./globals');
 
 function Test(title, fn) {
@@ -61,11 +62,6 @@ Test.prototype._setAssertError = function (err) {
 	this.assertError = err;
 };
 
-// Workaround for power-assert
-// `t` must be capturable for decorated assert output
-Test.prototype._capt = assert._capt;
-Test.prototype._expr = assert._expr;
-
 Test.prototype.plan = function (count) {
 	if (typeof count !== 'number') {
 		throw new TypeError('Expected a number');
@@ -208,9 +204,7 @@ Test.prototype._publicApi = function () {
 	[
 		'assertCount',
 		'title',
-		'end',
-		'_capt',
-		'_expr'
+		'end'
 	]
 		.forEach(function (name) {
 			Object.defineProperty(api, name, {
@@ -239,31 +233,46 @@ Test.prototype._publicApi = function () {
 		self._assert();
 	}
 
+	function onAssertionEvent(event) {
+		if (event.assertionThrew) {
+			event.error.powerAssertContext = event.powerAssertContext;
+			event.error.originalMessage = event.originalMessage;
+			self._setAssertError(event.error);
+			self._assert();
+			return null;
+		}
+
+		var fn = observableToPromise(event.returnValue);
+
+		if (isPromise(fn)) {
+			return Promise.resolve(fn)
+				.catch(function (err) {
+					err.originalMessage = event.originalMessage;
+					self._setAssertError(err);
+				})
+				.finally(function () {
+					self._assert();
+				});
+		}
+
+		self._assert();
+		return null;
+	}
+
+	var enhanced = enhanceAssert({
+		assert: assert,
+		onSuccess: onAssertionEvent,
+		onError: onAssertionEvent
+	});
+
 	// Patched assert methods: increase assert count and store errors.
 	Object.keys(assert).forEach(function (el) {
 		api.skip[el] = skipFn;
-		api[el] = function () {
-			try {
-				var fn = assert[el].apply(assert, arguments);
-
-				fn = observableToPromise(fn);
-
-				if (isPromise(fn)) {
-					return Promise.resolve(fn)
-						.catch(function (err) {
-							self._setAssertError(err);
-						})
-						.finally(function () {
-							self._assert();
-						});
-				}
-			} catch (err) {
-				self._setAssertError(err);
-			}
-
-			self._assert();
-		};
+		api[el] = enhanced[el].bind(enhanced);
 	});
 
+	api._capt = enhanced._capt.bind(enhanced);
+	api._expr = enhanced._expr.bind(enhanced);
+
 	return api;
 };

package.json

@@ -90,6 +90,7 @@
     "debug": "^2.2.0",
     "deeper": "^2.1.0",
     "empower": "^1.1.0",
+    "empower-core": "^0.2.0",
     "figures": "^1.4.0",
     "fn-name": "^2.0.0",
     "globby": "^4.0.0",

test/api.js

@@ -270,3 +270,24 @@ test('Node.js-style --require CLI argument', function (t) {
 			t.is(api.passCount, 1);
 		});
 });
+
+test('power-assert support', function (t) {
+	t.plan(3);
+
+	var api = new Api([path.join(__dirname, 'fixture/power-assert.js')]);
+
+	api.run()
+		.then(function () {
+			t.ok(api.errors[0].error.powerAssertContext);
+
+			t.match(
+				api.errors[0].error.message,
+				/t\.ok\(a === 'bar'\)\s*\n\s+\|\s*\n\s+"foo"/m
+			);
+
+			t.match(
+				api.errors[1].error.message,
+				/with message\s+t\.ok\(a === 'foo', 'with message'\)\s*\n\s+\|\s*\n\s+"bar"/m
+			);
+		});
+});

test/fixture/power-assert.js

@@ -1,7 +1,13 @@
 import test from '../../';
 
-test(t => {
+test.serial(t => {
 	const a = 'foo';
 
 	t.ok(a === 'bar');
 });
+
+test.serial(t => {
+	const a = 'bar';
+
+	t.ok(a === 'foo', 'with message');
+});