Teardowns run in reverse order

Fixes #2516.

Author: novemberborn

docs/02-execution-context.md

@@ -40,13 +40,13 @@ Plan how many assertions there are in the test. The test will fail if the actual
 
 ## `t.teardown(fn)`
 
-Registers the `fn` function to be run after the test has finished. You can register multiple functions and they'll run in order<sup>†</sup>. You can use asynchronous functions: only one will run at a time.
+Registers the `fn` function to be run after the test has finished. You can register multiple functions. In AVA 3 the functions are called in order, but in AVA 4 they'll run in _reverse_ order.<sup>†</sup>. You can use asynchronous functions: only one will run at a time.
 
 You cannot perform assertions using the `t` object or register additional functions from inside `fn`.
 
 You cannot use `t.teardown()` in hooks either.
 
-<sup>†</sup> In the next major release we'll change this so teardown functions run in reverse order. The last registered function will be called first. You can opt in to this behavior now by enabling the `reverseTeardowns` experiment.
+<sup>†</sup> You can opt in to this behavior in AVA 3 by enabling the `reverseTeardowns` experiment.
 
 **`package.json`**:
 

lib/load-config.js

@@ -10,7 +10,6 @@ const NO_SUCH_FILE = Symbol('no ava.config.js file');
 const MISSING_DEFAULT_EXPORT = Symbol('missing default export');
 const EXPERIMENTS = new Set([
 	'nextGenConfig',
-	'reverseTeardowns',
 	'sharedWorkers'
 ]);
 

lib/test.js

@@ -509,11 +509,7 @@ class Test {
 	}
 
 	async runTeardowns() {
-		const teardowns = [...this.teardowns];
-
-		if (this.experiments.reverseTeardowns) {
-			teardowns.reverse();
-		}
+		const teardowns = [...this.teardowns].reverse();
 
 		for (const teardown of teardowns) {
 			try {

test-tap/test.js

@@ -8,7 +8,7 @@ const sinon = require('sinon');
 const delay = require('delay');
 const snapshotManager = require('../lib/snapshot-manager');
 const Test = require('../lib/test');
-const {ava, withExperiments} = require('./helper/ava-test');
+const {ava} = require('./helper/ava-test');
 
 const failingTestHint = 'Test was expected to fail, but succeeded, you should stop marking the test as failing';
 
@@ -815,30 +815,14 @@ test('teardown awaits promise', t => {
 	});
 });
 
-test('teardowns run sequentially in order', t => {
-	const teardownA = sinon.stub().resolves(delay(200));
-	let resolveB;
-	const teardownB = sinon.stub().returns(new Promise(resolve => {
-		resolveB = resolve;
-	}));
-	return ava(a => {
-		a.teardown(() => teardownA().then(resolveB));
-		a.teardown(teardownB);
-		a.pass();
-	}).run().then(result => {
-		t.is(result.passed, true);
-		t.ok(teardownA.calledBefore(teardownB));
-	});
-});
-
-test('teardowns run in reverse order when the `reverseTeardowns` experimental feature is enabled', t => {
+test('teardowns run in reverse order', t => {
 	let resolveA;
 	const teardownA = sinon.stub().returns(new Promise(resolve => {
 		resolveA = resolve;
 	}));
 	const teardownB = sinon.stub().resolves(delay(200));
 
-	return withExperiments({reverseTeardowns: true})(a => {
+	return ava(a => {
 		a.teardown(teardownA);
 		a.teardown(() => teardownB().then(resolveA));
 		a.pass();
@@ -896,9 +880,9 @@ test('teardown errors are hidden behind assertion errors', t => {
 	});
 });
 
-test('teardowns errors do not stop next teardown from running', t => {
-	const teardownA = sinon.stub().throws('TeardownError');
-	const teardownB = sinon.spy();
+test('teardown errors do not stop next teardown from running', t => {
+	const teardownA = sinon.spy();
+	const teardownB = sinon.stub().throws('TeardownError');
 	return ava(a => {
 		a.teardown(teardownA);
 		a.teardown(teardownB);
@@ -908,7 +892,7 @@ test('teardowns errors do not stop next teardown from running', t => {
 		t.is(result.error.name, 'TeardownError');
 		t.ok(teardownA.calledOnce);
 		t.ok(teardownB.calledOnce);
-		t.ok(teardownA.calledBefore(teardownB));
+		t.ok(teardownB.calledBefore(teardownA));
 	});
 });