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[Breaking] support passing in an async function for the test callback #472

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merged 3 commits into from
Dec 18, 2019
Merged

[Breaking] support passing in an async function for the test callback #472

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8d3f03a
[Breaking] support exceptions in async functions
Raynos Jun 20, 2019
f248610
[Breaking] if a test callback returns a rejected thenable, fail the t…
ljharb Jun 24, 2019
197019c
[Tests] update tests for more async/await cases
Raynos Jul 2, 2019
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8 changes: 8 additions & 0 deletions .eslintrc
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Original file line number Diff line number Diff line change
Expand Up @@ -8,4 +8,12 @@
"named": "never",
}],
},
"overrides": [
{
"files": ["test/async-await/*"],
"parserOptions": {
"ecmaVersion": 2017,
},
},
],
}
21 changes: 20 additions & 1 deletion lib/test.js
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Original file line number Diff line number Diff line change
Expand Up @@ -91,7 +91,26 @@ Test.prototype.run = function () {
if (this._timeout != null) {
this.timeoutAfter(this._timeout);
}
this._cb(this);

var callbackReturn = this._cb(this);

if (
typeof Promise === 'function' &&
callbackReturn &&
typeof callbackReturn.then === 'function'
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) {
var self = this;
Promise.resolve(callbackReturn).then(function onResolve() {
if (!self.calledEnd) {
self.end();
}
}).catch(function onError(err) {
self.fail(err);
self.end();
});
return;
}

this.emit('run');
};

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231 changes: 231 additions & 0 deletions test/async-await.js
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@@ -0,0 +1,231 @@
var tap = require('tap');

var stripFullStack = require('./common').stripFullStack;
var runProgram = require('./common').runProgram;

var nodeVersion = process.versions.node;
var majorVersion = nodeVersion.split('.')[0];

if (Number(majorVersion) < 8) {
process.exit(0);
}

tap.test('async1', function (t) {
runProgram('async-await', 'async1.js', function (r) {
t.same(r.stdout.toString('utf8'), [
'TAP version 13',
'# async1',
'ok 1 before await',
'ok 2 after await',
'',
'1..2',
'# tests 2',
'# pass 2',
'',
'# ok'
].join('\n') + '\n\n');
t.same(r.exitCode, 0);
t.same(r.stderr.toString('utf8'), '');
t.end();
});
});

tap.test('async2', function (t) {
runProgram('async-await', 'async2.js', function (r) {
var stdout = r.stdout.toString('utf8');
var lines = stdout.split('\n');
lines = lines.filter(function (line) {
return ! /^(\s+)at(\s+)<anonymous>$/.test(line);
});
stdout = lines.join('\n');

t.same(stripFullStack(stdout), [
'TAP version 13',
'# async2',
'ok 1 before await',
'not ok 2 after await',
' ---',
' operator: ok',
' expected: true',
' actual: false',
' at: Test.myTest ($TEST/async-await/async2.js:$LINE:$COL)',
' stack: |-',
' Error: after await',
' [... stack stripped ...]',
' at Test.myTest ($TEST/async-await/async2.js:$LINE:$COL)',
' ...',
'',
'1..2',
'# tests 2',
'# pass 1',
'# fail 1'
].join('\n') + '\n\n');
t.same(r.exitCode, 1);
t.same(r.stderr.toString('utf8'), '');
t.end();
});
});

tap.test('async3', function (t) {
runProgram('async-await', 'async3.js', function (r) {
t.same(r.stdout.toString('utf8'), [
'TAP version 13',
'# async3',
'ok 1 before await',
'ok 2 after await',
'',
'1..2',
'# tests 2',
'# pass 2',
'',
'# ok'
].join('\n') + '\n\n');
t.same(r.exitCode, 0);
t.same(r.stderr.toString('utf8'), '');
t.end();
});
});

tap.test('async4', function (t) {
runProgram('async-await', 'async4.js', function (r) {
t.same(stripFullStack(r.stdout.toString('utf8')), [
'TAP version 13',
'# async4',
'ok 1 before await',
'not ok 2 Error: oops',
' ---',
' operator: error',
' expected: |-',
' undefined',
' actual: |-',
' [Error: oops]',
' at: Test.myTest ($TEST/async-await/async4.js:$LINE:$COL)',
' stack: |-',
' Error: oops',
' at Timeout.myTimeout [as _onTimeout] ($TEST/async-await/async4.js:$LINE:$COL)',
' [... stack stripped ...]',
' ...',
'',
'1..2',
'# tests 2',
'# pass 1',
'# fail 1'
].join('\n') + '\n\n');
t.same(r.exitCode, 1);
t.same(r.stderr.toString('utf8'), '');
t.end();
});
});

tap.test('async5', function (t) {
runProgram('async-await', 'async5.js', function (r) {
t.same(stripFullStack(r.stdout.toString('utf8')), [
'TAP version 13',
'# async5',
'ok 1 before server',
'ok 2 after server',
'ok 3 before request',
'ok 4 after request',
'ok 5 should be equal',
'ok 6 should be equal',
'ok 7 undefined',
'not ok 8 .end() called twice',
' ---',
' operator: fail',
' at: Server.<anonymous> ($TEST/async-await/async5.js:$LINE:$COL)',
' stack: |-',
' Error: .end() called twice',
' [... stack stripped ...]',
' at Server.<anonymous> ($TEST/async-await/async5.js:$LINE:$COL)',
' [... stack stripped ...]',
' ...',
'',
'1..8',
'# tests 8',
'# pass 7',
'# fail 1'
].join('\n') + '\n\n');
t.same(r.exitCode, 1);
t.same(r.stderr.toString('utf8'), '');
t.end();
});
});

tap.test('sync-error', function (t) {
runProgram('async-await', 'sync-error.js', function (r) {
t.same(stripFullStack(r.stdout.toString('utf8')), [
'TAP version 13',
'# sync-error',
'ok 1 before throw',
''
].join('\n'));
t.same(r.exitCode, 1);

var stderr = r.stderr.toString('utf8');
var lines = stderr.split('\n');
lines = lines.filter(function (line) {
return ! /\(timers.js:/.test(line) &&
! /\(internal\/timers.js:/.test(line) &&
! /Immediate\.next/.test(line);
});
stderr = lines.join('\n');

t.same(stripFullStack(stderr), [
'$TEST/async-await/sync-error.js:5',
' throw new Error(\'oopsie\');',
' ^',
'',
'Error: oopsie',
' at Test.myTest ($TEST/async-await/sync-error.js:$LINE:$COL)',
' at Test.bound [as _cb] ($TAPE/lib/test.js:$LINE:$COL)',
' at Test.run ($TAPE/lib/test.js:$LINE:$COL)',
' at Test.bound [as run] ($TAPE/lib/test.js:$LINE:$COL)',
''
].join('\n'));
t.end();
});
});

tap.test('async-error', function (t) {
runProgram('async-await', 'async-error.js', function (r) {
var stdout = r.stdout.toString('utf8');
var lines = stdout.split('\n');
lines = lines.filter(function (line) {
return ! /^(\s+)at(\s+)<anonymous>$/.test(line);
});
stdout = lines.join('\n');

t.same(stripFullStack(stdout.toString('utf8')), [
'TAP version 13',
'# async-error',
'ok 1 before throw',
'not ok 2 Error: oopsie',
' ---',
' operator: fail',
' stack: |-',
' Error: Error: oopsie',
' [... stack stripped ...]',
' ...',
'',
'1..2',
'# tests 2',
'# pass 1',
'# fail 1',
'',
'',
].join('\n'));
t.same(r.exitCode, 1);

var stderr = r.stderr.toString('utf8');
var lines = stderr.split('\n');
lines = lines.filter(function (line) {
return ! /\(timers.js:/.test(line) &&
! /\(internal\/timers.js:/.test(line) &&
! /Immediate\.next/.test(line);
});
stderr = lines.join('\n');

t.same(stderr, '');
t.end();
});
});
7 changes: 7 additions & 0 deletions test/async-await/async-error.js
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@@ -0,0 +1,7 @@
var test = require('../../');

test('async-error', async function myTest(t) {
t.ok(true, 'before throw');
throw new Error('oopsie');
t.ok(true, 'after throw');
});
14 changes: 14 additions & 0 deletions test/async-await/async1.js
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@@ -0,0 +1,14 @@
var test = require('../../');

test('async1', async function myTest(t) {
try {
t.ok(true, 'before await');
await new Promise((resolve) => {
setTimeout(resolve, 10);
});
t.ok(true, 'after await');
t.end();
} catch (err) {
t.ifError(err);
}
});
13 changes: 13 additions & 0 deletions test/async-await/async2.js
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@@ -0,0 +1,13 @@
var test = require('../../');

test('async2', async function myTest(t) {
try {
t.ok(true, 'before await');
await new Promise((resolve) => {
setTimeout(resolve, 10);
});
t.ok(false, 'after await');
} catch (err) {
t.ifError(err);
}
});
9 changes: 9 additions & 0 deletions test/async-await/async3.js
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@@ -0,0 +1,9 @@
var test = require('../../');

test('async3', async function myTest(t) {
t.ok(true, 'before await');
await new Promise((resolve) => {
setTimeout(resolve, 10);
});
t.ok(true, 'after await');
});
15 changes: 15 additions & 0 deletions test/async-await/async4.js
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@@ -0,0 +1,15 @@
var test = require('../../');

test('async4', async function myTest(t) {
try {
t.ok(true, 'before await');
await new Promise((resolve, reject) => {
setTimeout(function myTimeout() {
reject(new Error('oops'));
}, 10);
});
t.ok(true, 'after await');
} catch (err) {
t.ifError(err);
}
});
57 changes: 57 additions & 0 deletions test/async-await/async5.js
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@@ -0,0 +1,57 @@
var util = require('util');
var http = require('http');

var test = require('../../');

test('async5', async function myTest(t) {
try {
t.ok(true, 'before server');

var mockDb = { state: 'old' };
var server = http.createServer(function (req, res) {
res.end('OK');

// Pretend we write to the DB and it takes time.
setTimeout(function () {
mockDb.state = 'new';
}, 10);
});

await util.promisify(function (cb) {
server.listen(0, cb);
})();

t.ok(true, 'after server');

t.ok(true, 'before request');

var res = await util.promisify(function (cb) {
var req = http.request({
hostname: 'localhost',
port: server.address().port,
path: '/',
method: 'GET'
}, function (res) {
cb(null, res);
});
req.end();
})();

t.ok(true, 'after request');

res.resume();
t.equal(res.statusCode, 200);

setTimeout(function () {
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@ljharb ljharb Jun 29, 2019 •
edited
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note that using setTimeout alone in a world of promises slash async/await is a bug. This should be awaiting a new Promise that wraps the setTimeout, so that its fate is tied to the overarching promise of the async function.

I've fixed this in the rebase.

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It’s a bad practice but not a bug.

I’ve seen plenty of people mixing promises, async/await and callbacks

Adding ‘data’ listeners is the biggest example of mixing callbacks and promises.

This is a best practice we will need to educate the tape users on

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I consider those two things the same thing :-)

If you're returning a promise - which is always the case when using an async function - you are explicitly stating that your function resolves to a single future async value. Thus, every single async action you create needs to be tied to the fate of that promise.

If that's not the case, take a callback and don't be an async function/don't return a promise.

I agree educating tape users might be needed.

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100% agreed, mixing callbacks & promises is a terrible idea.

But I suspect our users might do it none the less and tape already "supports" async functions if you call t.end() and happen to not throw an exception so we might break existing tests

t.equal(mockDb.state, 'new');

server.close(function (err) {
t.ifError(err);
t.end();
});
}, 50);
} catch (err) {
t.ifError(err);
t.end();
}
});
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