Replace powerAssert option by compileEnhancements

This new option controls whether the @ava/transform-test-files preset is
used at all. Disabling will be one of the things necessary to side-step
Babel altogether.

Removes support for the `--no-power-assert` CLI flag, without a
replacement.

Refs #1556.

Author: novemberborn

api.js

@@ -117,8 +117,8 @@ class Api extends EventEmitter {
 
 		this.options.cacheDir = cacheDir;
 
-		const isPowerAssertEnabled = this.options.powerAssert !== false;
-		return babelConfigHelper.build(this.options.projectDir, cacheDir, this.options.babelConfig, isPowerAssertEnabled)
+		const compileEnhancements = this.options.compileEnhancements !== false;
+		return babelConfigHelper.build(this.options.projectDir, cacheDir, this.options.babelConfig, compileEnhancements)
 			.then(result => {
 				this.precompiler = new CachingPrecompiler({
 					path: cacheDir,

lib/babel-config.js

@@ -82,7 +82,7 @@ function resolveOptions(baseConfig, cache, envName, optionsFile, verifierFile) {
 		});
 }
 
-function build(projectDir, cacheDir, userOptions, powerAssert) {
+function build(projectDir, cacheDir, userOptions, compileEnhancements) {
 	// Note that Babel ignores empty string values, even for NODE_ENV. Here
 	// default to 'test' unless NODE_ENV is defined, in which case fall back to
 	// Babel's default of 'development' if it's empty.
@@ -108,10 +108,11 @@ function build(projectDir, cacheDir, userOptions, powerAssert) {
 	const baseOptions = {
 		babelrc: false,
 		plugins: [],
-		presets: [
-			['@ava/transform-test-files', {powerAssert}]
-		]
+		presets: []
 	};
+	if (compileEnhancements) {
+		baseOptions.presets.push(['@ava/transform-test-files', {powerAssert: true}]);
+	}
 	if (userOptions === 'default') {
 		baseOptions.presets.unshift('@ava/stage-4');
 	}

lib/cli.js

@@ -37,7 +37,6 @@ exports.run = () => {
 		  --tap, -t               Generate TAP output
 		  --verbose, -v           Enable verbose output
 		  --no-cache              Disable the transpiler cache
-		  --no-power-assert       Disable Power Assert
 		  --color                 Force color output
 		  --no-color              Disable color output
 		  --match, -m             Only run tests with matching title (Can be repeated)
@@ -80,7 +79,6 @@ exports.run = () => {
 			failFast: conf.failFast,
 			init: conf.init,
 			match: conf.match,
-			powerAssert: conf.powerAssert,
 			serial: conf.serial,
 			tap: conf.tap,
 			timeout: conf.timeout,
@@ -140,7 +138,7 @@ exports.run = () => {
 		serial: conf.serial,
 		require: arrify(conf.require),
 		cacheEnabled: conf.cache !== false,
-		powerAssert: conf.powerAssert !== false,
+		compileEnhancements: conf.compileEnhancements !== false,
 		explicitTitles: conf.watch,
 		match: arrify(conf.match),
 		babelConfig: babelConfigHelper.validate(conf.babel),

readme.md

@@ -163,7 +163,6 @@ $ ava --help
     --tap, -t               Generate TAP output
     --verbose, -v           Enable verbose output
     --no-cache              Disable the transpiler cache
-    --no-power-assert       Disable Power Assert
     --color                 Force color output
     --no-color              Disable color output
     --match, -m             Only run tests with matching title (Can be repeated)
@@ -266,7 +265,7 @@ All of the CLI options can be configured in the `ava` section of your `package.j
 		"failFast": true,
 		"failWithoutAssertions": false,
 		"tap": true,
-		"powerAssert": false,
+		"compileEnhancements": false,
 		"require": [
 			"babel-register"
 		],
@@ -286,7 +285,7 @@ Arguments passed to the CLI will always take precedence over the configuration i
 - `failWithoutAssertions`: if `false`, does not fail a test if it doesn't run [assertions](#assertions)
 - `tap`: if `true`, enables the [TAP reporter](#tap-reporter)
 - `snapshotDir`: specifies a fixed location for storing snapshot files. Use this if your snapshots are ending up in the wrong location
-- `powerAssert`: if `false`, disables [power-assert](https://github.com/power-assert-js/power-assert) which otherwise helps provide more descriptive error messages
+- `compileEnhancements`: if `false`, disables [power-assert](https://github.com/power-assert-js/power-assert) — which otherwise helps provide more descriptive error messages — and detection of improper use of the `t.throws()` assertion
 - `require`: extra modules to require before tests are run. Modules are required in the [worker processes](#process-isolation)
 - `babel`: test file specific Babel options. See [ES2017 support](#es2017-support) for more details
 

test/api.js

@@ -13,7 +13,6 @@ const ROOT_DIR = path.join(__dirname, '..');
 function apiCreator(options) {
 	options = options || {};
 	options.babelConfig = options.babelConfig || 'default';
-	options.powerAssert = true;
 	options.projectDir = options.projectDir || ROOT_DIR;
 	options.resolveTestsFrom = options.resolveTestsFrom || options.projectDir;
 	const instance = new Api(options);

test/babel-config.js

@@ -38,36 +38,36 @@ function withNodeEnv(value, run) {
 
 test('uses default presets when userOptions is "default"', t => {
 	const userOptions = 'default';
-	const powerAssert = true;
+	const compileEnhancements = true;
 
 	const projectDir = uniqueTempDir();
 	const cacheDir = path.join(projectDir, 'cache');
-	return babelConfigHelper.build(projectDir, cacheDir, userOptions, powerAssert)
+	return babelConfigHelper.build(projectDir, cacheDir, userOptions, compileEnhancements)
 		.then(result => {
 			const options = result.getOptions();
 
 			t.false(options.babelrc);
 			t.is(options.presets[0][0].wrapped, require('@ava/babel-preset-stage-4'));
 			t.is(options.presets[1][0].wrapped, require('@ava/babel-preset-transform-test-files'));
-			t.same(options.presets[1][1], {powerAssert});
+			t.same(options.presets[1][1], {powerAssert: true});
 		});
 });
 
 test('uses options from babelrc when userOptions is "inherit"', t => {
 	const userOptions = 'inherit';
-	const powerAssert = true;
+	const compileEnhancements = true;
 
 	const projectDir = fixture('babelrc');
 	const cacheDir = path.join(uniqueTempDir(), 'cache');
-	return babelConfigHelper.build(projectDir, cacheDir, userOptions, powerAssert)
+	return babelConfigHelper.build(projectDir, cacheDir, userOptions, compileEnhancements)
 		.then(result => {
 			const options = result.getOptions();
 
 			t.false(options.babelrc);
 			t.is(options.plugins[0][0].wrapped, require(fixture('babel-plugin-test-doubler')));
 			t.is(options.presets[0][0].wrapped, require('@ava/babel-preset-stage-4'));
 			t.is(options.presets[1][0].wrapped, require('@ava/babel-preset-transform-test-files'));
-			t.same(options.presets[1][1], {powerAssert});
+			t.same(options.presets[1][1], {powerAssert: true});
 		});
 });
 
@@ -78,54 +78,54 @@ test('uses userOptions for babel options when userOptions is an object', t => {
 		plugins: [customFile],
 		presets: [customFile]
 	};
-	const powerAssert = true;
+	const compileEnhancements = true;
 
 	const projectDir = uniqueTempDir();
 	const cacheDir = path.join(projectDir, 'cache');
-	return babelConfigHelper.build(projectDir, cacheDir, userOptions, powerAssert)
+	return babelConfigHelper.build(projectDir, cacheDir, userOptions, compileEnhancements)
 		.then(result => {
 			const options = result.getOptions();
 			t.false(options.babelrc);
 			t.is(options.plugins[0][0].wrapped, custom);
 			t.is(options.presets[0][0].wrapped, custom);
 			t.is(options.presets[1][0].wrapped, require('@ava/babel-preset-transform-test-files'));
-			t.same(options.presets[1][1], {powerAssert});
+			t.same(options.presets[1][1], {powerAssert: true});
 		});
 });
 
 test('uses "development" environment if NODE_ENV is the empty string', t => {
 	const userOptions = 'inherit';
-	const powerAssert = true;
+	const compileEnhancements = true;
 
 	const projectDir = fixture('babelrc');
 	const cacheDir = path.join(uniqueTempDir(), 'cache');
-	return withNodeEnv('', () => babelConfigHelper.build(projectDir, cacheDir, userOptions, powerAssert))
+	return withNodeEnv('', () => babelConfigHelper.build(projectDir, cacheDir, userOptions, compileEnhancements))
 		.then(result => {
 			const options = result.getOptions();
 
 			t.false(options.babelrc);
 			t.is(options.plugins[0][0].wrapped, require(fixture('babel-plugin-test-capitalizer')));
 			t.is(options.presets[0][0].wrapped, require('@ava/babel-preset-stage-4'));
 			t.is(options.presets[1][0].wrapped, require('@ava/babel-preset-transform-test-files'));
-			t.same(options.presets[1][1], {powerAssert});
+			t.same(options.presets[1][1], {powerAssert: true});
 		});
 });
 
 test('supports .babelrc.js files', t => {
 	const userOptions = 'inherit';
-	const powerAssert = true;
+	const compileEnhancements = true;
 
 	const projectDir = fixture('babelrc-js');
 	const cacheDir = path.join(uniqueTempDir(), 'cache');
-	return babelConfigHelper.build(projectDir, cacheDir, userOptions, powerAssert)
+	return babelConfigHelper.build(projectDir, cacheDir, userOptions, compileEnhancements)
 		.then(result => {
 			const options = result.getOptions();
 
 			t.false(options.babelrc);
 			t.is(options.plugins[0][0].wrapped, require(fixture('babel-plugin-test-doubler')));
 			t.is(options.presets[0][0].wrapped, require('@ava/babel-preset-stage-4'));
 			t.is(options.presets[1][0].wrapped, require('@ava/babel-preset-transform-test-files'));
-			t.same(options.presets[1][1], {powerAssert});
+			t.same(options.presets[1][1], {powerAssert: true});
 		});
 });
 
@@ -162,18 +162,18 @@ test('does not add babel-plugin-syntax-object-rest-spread for node versions < 8.
 		});
 });
 
-test('should disable power-assert when powerAssert is false', t => {
+test('should not include transform-test-files when compileEnhancements is false', t => {
 	const userOptions = 'default';
-	const powerAssert = false;
+	const compileEnhancements = false;
 
 	const projectDir = uniqueTempDir();
 	const cacheDir = path.join(projectDir, 'cache');
-	return babelConfigHelper.build(projectDir, cacheDir, userOptions, powerAssert)
+	return babelConfigHelper.build(projectDir, cacheDir, userOptions, compileEnhancements)
 		.then(result => {
 			const options = result.getOptions();
 
 			t.false(options.babelrc);
-			t.same(options.presets[1][1], {powerAssert});
+			t.is(options.presets.length, 1);
 		});
 });