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How to use assertions.throws method in ava

Best JavaScript code snippet using ava

assert.js

Source:assert.js

...582});583test('.throws()', gather(t => {584	// Fails because function doesn't throw.585	failsWith(t, () => {586		assertions.throws(() => {});587	}, {588		assertion: 'throws',589		message: '',590		values: [{label: 'Function returned:', formatted: /undefined/}]591	});592	// Fails because function doesn't throw. Asserts that 'my message' is used593	// as the assertion message (*not* compared against the error).594	failsWith(t, () => {595		assertions.throws(() => {}, null, 'my message');596	}, {597		assertion: 'throws',598		message: 'my message',599		values: [{label: 'Function returned:', formatted: /undefined/}]600	});601	// Fails because the function returned a promise.602	failsWith(t, () => {603		assertions.throws(() => Promise.resolve());604	}, {605		assertion: 'throws',606		message: '',607		values: [{label: 'Function returned a promise. Use `t.throwsAsync()` instead:', formatted: /Promise/}]608	});609	// Fails because thrown exception is not an error610	failsWith(t, () => {611		assertions.throws(() => {612			const err = 'foo';613			throw err;614		});615	}, {616		assertion: 'throws',617		message: '',618		values: [619			{label: 'Function threw exception that is not an error:', formatted: /'foo'/}620		]621	});622	// Fails because thrown error's message is not equal to 'bar'623	failsWith(t, () => {624		const err = new Error('foo');625		assertions.throws(() => {626			throw err;627		}, 'bar');628	}, {629		assertion: 'throws',630		message: '',631		values: [632			{label: 'Function threw unexpected exception:', formatted: /foo/},633			{label: 'Expected message to equal:', formatted: /bar/}634		]635	});636	// Fails because thrown error is not the right instance637	failsWith(t, () => {638		const err = new Error('foo');639		assertions.throws(() => {640			throw err;641		}, class Foo {});642	}, {643		assertion: 'throws',644		message: '',645		values: [646			{label: 'Function threw unexpected exception:', formatted: /foo/},647			{label: 'Expected instance of:', formatted: /Foo/}648		]649	});650	// Passes because thrown error's message is equal to 'bar'651	passes(t, () => {652		const err = new Error('foo');653		assertions.throws(() => {654			throw err;655		}, 'foo');656	});657	// Passes because an error is thrown.658	passes(t, () => {659		assertions.throws(() => {660			throw new Error('foo');661		});662	});663	// Passes because the correct error is thrown.664	passes(t, () => {665		const err = new Error('foo');666		assertions.throws(() => {667			throw err;668		}, {is: err});669	});670	// Fails because the thrown value is not an error671	fails(t, () => {672		const obj = {};673		assertions.throws(() => {674			throw obj;675		}, {is: obj});676	});677	// Fails because the thrown value is not the right one678	fails(t, () => {679		const err = new Error('foo');680		assertions.throws(() => {681			throw err;682		}, {is: {}});683	});684	// Passes because the correct error is thrown.685	passes(t, () => {686		assertions.throws(() => {687			throw new TypeError(); // eslint-disable-line unicorn/error-message688		}, {name: 'TypeError'});689	});690	// Fails because the thrown value is not an error691	fails(t, () => {692		assertions.throws(() => {693			const err = {name: 'Bob'};694			throw err;695		}, {name: 'Bob'});696	});697	// Fails because the thrown value is not the right one698	fails(t, () => {699		assertions.throws(() => {700			throw new Error('foo');701		}, {name: 'TypeError'});702	});703	// Passes because the correct error is thrown.704	passes(t, () => {705		assertions.throws(() => {706			const err = new TypeError(); // eslint-disable-line unicorn/error-message707			err.code = 'ERR_TEST';708			throw err;709		}, {code: 'ERR_TEST'});710	});711	// Passes because the correct error is thrown.712	passes(t, () => {713		assertions.throws(() => {714			const err = new TypeError(); // eslint-disable-line unicorn/error-message715			err.code = 42;716			throw err;717		}, {code: 42});718	});719	// Fails because the thrown value is not the right one720	fails(t, () => {721		assertions.throws(() => {722			const err = new TypeError(); // eslint-disable-line unicorn/error-message723			err.code = 'ERR_NOPE';724			throw err;725		}, {code: 'ERR_TEST'});726	});727}));728test('.throws() returns the thrown error', t => {729	const expected = new Error();730	const actual = assertions.throws(() => {731		throw expected;732	});733	t.is(actual, expected);734	t.end();735});736test('.throwsAsync()', gather(t => {737	// Fails because the promise is resolved, not rejected.738	eventuallyFailsWith(t, () => assertions.throwsAsync(Promise.resolve('foo')), {739		assertion: 'throwsAsync',740		message: '',741		values: [{label: 'Promise resolved with:', formatted: /'foo'/}]742	});743	// Fails because the promise is resolved with an Error744	eventuallyFailsWith(t, () => assertions.throwsAsync(Promise.resolve(new Error())), {745		assertion: 'throwsAsync',746		message: '',747		values: [{label: 'Promise resolved with:', formatted: /Error/}]748	});749	// Fails because the function returned a promise that resolved, not rejected.750	eventuallyFailsWith(t, () => assertions.throwsAsync(() => Promise.resolve('foo')), {751		assertion: 'throwsAsync',752		message: '',753		values: [{label: 'Returned promise resolved with:', formatted: /'foo'/}]754	});755	// Passes because the promise was rejected with an error.756	eventuallyPasses(t, () => assertions.throwsAsync(Promise.reject(new Error())));757	// Passes because the function returned a promise rejected with an error.758	eventuallyPasses(t, () => assertions.throwsAsync(() => Promise.reject(new Error())));759	// Passes because the error's message matches the regex760	eventuallyPasses(t, () => assertions.throwsAsync(Promise.reject(new Error('abc')), /abc/));761	// Fails because the error's message does not match the regex762	eventuallyFailsWith(t, () => assertions.throwsAsync(Promise.reject(new Error('abc')), /def/), {763		assertion: 'throwsAsync',764		message: '',765		values: [766			{label: 'Promise rejected with unexpected exception:', formatted: /Error/},767			{label: 'Expected message to match:', formatted: /\/def\//}768		]769	});770	// Fails because the function throws synchronously771	eventuallyFailsWith(t, () => assertions.throwsAsync(() => {772		throw new Error('sync');773	}, null, 'message'), {774		assertion: 'throwsAsync',775		message: 'message',776		values: [777			{label: 'Function threw synchronously. Use `t.throws()` instead:', formatted: /Error/}778		]779	});780	// Fails because the function did not return a promise781	eventuallyFailsWith(t, () => assertions.throwsAsync(() => {}, null, 'message'), {782		assertion: 'throwsAsync',783		message: 'message',784		values: [785			{label: 'Function returned:', formatted: /undefined/}786		]787	});788}));789test('.throwsAsync() returns the rejection reason of promise', t => {790	const expected = new Error();791	return assertions.throwsAsync(Promise.reject(expected)).then(actual => {792		t.is(actual, expected);793		t.end();794	});795});796test('.throwsAsync() returns the rejection reason of a promise returned by the function', t => {797	const expected = new Error();798	return assertions.throwsAsync(() => {799		return Promise.reject(expected);800	}).then(actual => {801		t.is(actual, expected);802		t.end();803	});804});805test('.throws() fails if passed a bad value', t => {806	failsWith(t, () => {807		assertions.throws('not a function');808	}, {809		assertion: 'throws',810		message: '`t.throws()` must be called with a function',811		values: [{label: 'Called with:', formatted: /not a function/}]812	});813	t.end();814});815test('.throwsAsync() fails if passed a bad value', t => {816	failsWith(t, () => {817		assertions.throwsAsync('not a function');818	}, {819		assertion: 'throwsAsync',820		message: '`t.throwsAsync()` must be called with a function or promise',821		values: [{label: 'Called with:', formatted: /not a function/}]822	});823	t.end();824});825test('.throws() fails if passed a bad expectation', t => {826	failsWith(t, () => {827		assertions.throws(() => {}, true);828	}, {829		assertion: 'throws',830		message: 'The second argument to `t.throws()` must be a function, string, regular expression, expectation object or `null`',831		values: [{label: 'Called with:', formatted: /true/}]832	});833	failsWith(t, () => {834		assertions.throws(() => {}, {});835	}, {836		assertion: 'throws',837		message: 'The second argument to `t.throws()` must be a function, string, regular expression, expectation object or `null`',838		values: [{label: 'Called with:', formatted: /\{\}/}]839	});840	failsWith(t, () => {841		assertions.throws(() => {}, []);842	}, {843		assertion: 'throws',844		message: 'The second argument to `t.throws()` must be a function, string, regular expression, expectation object or `null`',845		values: [{label: 'Called with:', formatted: /\[\]/}]846	});847	failsWith(t, () => {848		assertions.throws(() => {}, {code: {}});849	}, {850		assertion: 'throws',851		message: 'The `code` property of the second argument to `t.throws()` must be a string or number',852		values: [{label: 'Called with:', formatted: /code: {}/}]853	});854	failsWith(t, () => {855		assertions.throws(() => {}, {instanceOf: null});856	}, {857		assertion: 'throws',858		message: 'The `instanceOf` property of the second argument to `t.throws()` must be a function',859		values: [{label: 'Called with:', formatted: /instanceOf: null/}]860	});861	failsWith(t, () => {862		assertions.throws(() => {}, {message: null});863	}, {864		assertion: 'throws',865		message: 'The `message` property of the second argument to `t.throws()` must be a string or regular expression',866		values: [{label: 'Called with:', formatted: /message: null/}]867	});868	failsWith(t, () => {869		assertions.throws(() => {}, {name: null});870	}, {871		assertion: 'throws',872		message: 'The `name` property of the second argument to `t.throws()` must be a string',873		values: [{label: 'Called with:', formatted: /name: null/}]874	});875	failsWith(t, () => {876		assertions.throws(() => {}, {is: {}, message: '', name: '', of() {}, foo: null});877	}, {878		assertion: 'throws',879		message: 'The second argument to `t.throws()` contains unexpected properties',880		values: [{label: 'Called with:', formatted: /foo: null/}]881	});882	t.end();883});884test('.throwsAsync() fails if passed a bad expectation', t => {885	failsWith(t, () => {886		assertions.throwsAsync(() => {}, true);887	}, {888		assertion: 'throwsAsync',889		message: 'The second argument to `t.throwsAsync()` must be a function, string, regular expression, expectation object or `null`',890		values: [{label: 'Called with:', formatted: /true/}]...

throws_test.js

Source:throws_test.js

1import jutest from 'jutest';2import assertions from "assertions/all";3jutest('assertions.throws()', s => {4  s.describe('basic behaviour', s => {5    s.test('passes if provided expression throws', t => {6      let result = assertions.throws(() => { throw 'foobar'; }, 'foobar');7      t.equal(result.passed, true);8      t.equal(result.actual, 'foobar');9      t.equal(result.expected, 'foobar');10      t.equal(result.operator, 'throws');11    });12    s.test('fails if provided expression doesnt throw', t => {13      let result = assertions.throws(() => { }, Error);14      t.equal(result.passed, false);15      t.equal(result.actual, undefined);16      t.equal(result.expected, Error);17      t.equal(result.operator, 'throws');18      t.match(result.failureMessage, /no errors/);19    });20    s.test("fails if error doesn't match the expectation", t => {21      let result = assertions.throws(() => { throw Error('baz'); }, 'bar');22      t.match(result.failureMessage, /baz/);23    });24  });...

Using AI Code Generation

1import test from 'ava';2test(t => {3  const err = t.throws(() => {4    throw new Error('foo');5  }, Error);6  t.is(err.message, 'foo');7});8test(t => {9  const err = t.throws(() => {10    throw new TypeError('bar');11  }, TypeError);12  t.is(err.message, 'bar');13});14test(t => {15  t.throws(() => {16    throw new TypeError('bar');17  }, 'bar');18});19test(t => {20  t.throws(() => {21    throw new TypeError('bar');22  }, TypeError, 'bar');23});24test(t => {25  const err = t.throws(() => {26    throw new TypeError('bar');27  }, TypeError);28  t.is(err.message, 'bar');29});30test(t => {31  const err = t.throws(() => {32    throw new TypeError('bar');33  }, TypeError);34  t.is(err.message, 'bar');35});36test(t => {37  t.throws(() => {38    throw new TypeError('bar');39  }, 'bar');40});41test(t => {42  t.throws(() => {43    throw new TypeError('bar');44  }, TypeError, 'bar');45});46test(t => {47  t.throws(() => {48    throw new TypeError('bar');49  }, /bar/);50});51test(t => {52  t.throws(() => {53    throw new TypeError('bar');54  }, TypeError, /bar/);55});56test(t => {57  t.throws(() => {58    throw new TypeError('bar');59  }, TypeError, 'bar');60});61test(t => {62  t.throws(() => {63    throw new TypeError('bar');64  }, TypeError, /bar/);65});66test(t => {67  t.throws(() => {68    throw new TypeError('bar');69  }, TypeError, 'bar');70});71test(t => {72  t.throws(() => {73    throw new TypeError('bar');74  }, TypeError, /bar/);75});76test(t => {77  t.throws(() => {78    throw new TypeError('bar');79  }, TypeError, 'bar');80});81test(t => {82  t.throws(() => {83    throw new TypeError('bar');84  }, TypeError, /bar/);85});

Using AI Code Generation

1const test = require('ava');2const { throws } = require('assert');3function fn() {4    throw new TypeError('Wrong value');5}6test('throws', t => {7    const error = t.throws(fn, TypeError);8    t.is(error.message, 'Wrong value');9});10test('throws with promise', async t => {11    await t.throwsAsync(fn, TypeError);12});13test('throws with async function', async t => {14    const error = await t.throwsAsync(async () => {15        await Promise.resolve(true);16        throw new TypeError('Wrong value');17    }, TypeError);18    t.is(error.message, 'Wrong value');19});20const test = require('ava');21const { notThrows } = require('assert');22function fn() {23    return true;24}25test('notThrows', t => {26    t.notThrows(fn);27});28test('notThrows with promise', async t => {29    await t.notThrowsAsync(Promise.resolve(true));30});31test('notThrows with async function', async t => {32    await t.notThrowsAsync(async () => {33        await Promise.resolve(true);34    });35});36const test = require('ava');37const { regex } = require('assert');38test('regex', t => {39    t.regex('I love AVA', /AVA/);40    t.notRegex('I love AVA', /ava/);41});42const test = require('ava');43const { ifError } = require('assert');44test('ifError', t => {45    t.ifError(false);46    t.ifError(0);47    t.ifError(null);48    t.ifError(undefined);49    t.ifError('');50    t.ifError(NaN);51    t.ifError(new Error());52});53const test = require('ava');54const { snapshot } = require('assert');55test('snapshot', t => {56    t.snapshot({ foo: 'bar' });57});58const test = require('ava');59const { log } = require('assert');60test('log', t => {61    t.log('Hello

Using AI Code Generation

1const test = require('ava');2const myMath = require('../src/myMath.js');3test('throws on negative numbers', t => {4    const error = t.throws(() => {5        myMath.add(-1, 2);6    }, Error);7    t.is(error.message, 'Negative numbers are not supported');8});9test('throws on negative numbers', t => {10    const error = t.throws(() => {11        myMath.add(-1, 2);12    }, Error);13    t.is(error.message, 'Negative numbers are not supported');14});15const test = require('ava');16const myMath = require('../src/myMath.js');17test('throws on negative numbers', async t => {18    const error = await t.throwsAsync(() => {19        myMath.addAsync(-1, 2);20    }, Error);21    t.is(error.message, 'Negative numbers are not supported');22});23test('throws on negative numbers', async t => {24    const error = await t.throwsAsync(() => {25        myMath.addAsync(-1, 2);26    }, Error);27    t.is(error.message, 'Negative numbers are not supported');28});29const test = require('ava');30const myMath = require('../src/myMath.js');31test('does not throw on positive numbers', t => {32    t.notThrows(() => {33        myMath.add(1, 2);34    });35});36test('does not throw on positive numbers', t => {37    t.notThrows(() => {38        myMath.add(1, 2);39    });40});41const test = require('ava');42const myMath = require('../src/myMath.js');43test('does not throw on positive numbers', async t => {44    await t.notThrowsAsync(() => {45        myMath.addAsync(1, 2);46    });47});48test('does not throw on positive numbers', async t => {49    await t.notThrowsAsync(() => {50        myMath.addAsync(1, 2);51    });52});53const test = require('ava');54const myMath = require('../src/myMath.js');55test('

Using AI Code Generation

1const test = require('ava');2const assert = require('assert');3const { throws } = require('assert/strict');4test('throws', t => {5  assert.throws(6    () => {7      throw new TypeError('Wrong value');8    },9    {10    }11  );12});

Using AI Code Generation

1const test = require('ava');2const fn = require('./');3test(t => {4	const err = t.throws(() => fn(100), TypeError);5	t.is(err.message, 'Expected a string, got number');6});

Using AI Code Generation

1import test from 'ava';2import {throws} from 'assert';3import {parse} from 'babylon';4import {generate} from 'babel-generator';5import {transformFromAst} from 'babel-core';6import {transform} from 'babel-core';7import {readFileSync} from 'fs';8import {join} from 'path';9import {Plugin} from 'broccoli-plugin';10import {build} from 'broccoli-test-helper';11import {Promise} from 'rsvp';12import broccoliBabelTranspiler from '../lib/index';13const fixture = (file) => readFileSync(join(__dirname, 'fixtures', file), 'utf8');14test('should compile ES6 to ES5', async (t) => {15  const node = new broccoliBabelTranspiler('test/fixtures/basic');16  const result = await build(node);17  t.is(result.read().toString(), fixture('basic.expected.js'));18});19test('should compile ES6 to ES5 with options', async (t) => {20  const node = new broccoliBabelTranspiler('test/fixtures/options', {21    getModuleId: function (name) {22      return name.replace(/-([a-z])/g, function (g) { return g[1].toUpperCase(); });23    }24  });25  const result = await build(node);26  t.is(result.read().toString(), fixture('options.expected.js'));27});28test('should compile ES6 to ES5 with a custom parser', async (t) => {29  const node = new broccoliBabelTranspiler('test/fixtures/parser', {30    parserOpts: {31    }32  });33  const result = await build(node);34  t.is(result.read().toString(), fixture('parser.expected.js'));35});36test('should compile ES6 to ES5 with a custom generator', async (t) => {37  const node = new broccoliBabelTranspiler('test/fixtures/generator', {38    generatorOpts: {39    }40  });41  const result = await build(node);42  t.is(result.read().toString(), fixture('generator.expected.js'));43});44test('should compile ES6 to ES5 with a custom babel', async (t) => {45  const node = new broccoliBabelTranspiler('test/fixtures/babel', {46    babel: {

Using AI Code Generation

1const test = require('ava');2test('throws if no arguments', t => {3	t.throws(() => {4	});5});6const test = require('ava');7test('throws if no arguments', t => {8	t.throws(() => {9		throw new TypeError('Missing argument');10	});11});12const test = require('ava');13test('throws if no arguments', t => {14	t.throws(() => {15		throw new TypeError('Missing argument');16	}, TypeError);17});18const test = require('ava');19test('throws if no arguments', t => {20	t.throws(() => {21		throw new TypeError('Missing argument');22	}, TypeError, 'Missing argument');23});24const test = require('ava');25test('throws if no arguments', t => {26	t.throws(() => {27		throw new TypeError('Missing argument');28	}, {29	});30});31const test = require('ava');32test('throws if no arguments', t => {33	t.throws(() => {34		throw new TypeError('Missing argument');35	}, TypeError);36});37const test = require('ava');38test('throws if no arguments', t => {39	t.throws(() => {40		throw new TypeError('Missing argument');41	}, TypeError, 'Missing argument');42});43const test = require('ava');44test('throws if no arguments', t => {45	t.throws(() => {46		throw new TypeError('Missing argument');47	}, {48	});49});50const test = require('ava');51test('throws if no arguments', t => {52	t.throws(() => {53		throw new TypeError('Missing argument');54	}, TypeError);55});56const test = require('ava');57test('throws if no arguments', t => {58	t.throws(() => {59		throw new TypeError('Missing argument');60	}, TypeError, 'Missing argument');61});62const test = require('ava');63test('throws if no arguments', t => {64	t.throws(() => {65		throw new TypeError('Missing argument');66	}, {67	});68});

Using AI Code Generation

1const test = require('ava');2const { throws } = require('assert');3const { throwSync } = require('assert/strict');4const { strict } = require('assert');5const { strictEqual } = require('assert');6function sum(a,b){7    return a + b;8}9test('sum of 2 and 2 is 4', t => {10    t.is(sum(2,2), 4);11});12test('sum of 2 and 3 is 5', t => {13    t.is(sum(2,3), 5);14});15test('sum of 2 and 3 is not 4', t => {16    t.not(sum(2,3), 4);17});18test('sum of 2 and 3 is not 4', t => {19    t.not(sum(2,3), 4);20});21test('throws an error', t => {22    const error = t.throws(() => {23        throw new Error('error');24    });25    t.is(error.message, 'error');26});27test('throws an error', t => {28    const error = t.throws(() => {29        throw new Error('error');30    });31    t.is(error.message, 'error');32});33test('does not throw an error', t => {34    t.notThrows(() => {35        sum(2,3);36    });37});38test('deep equality', t => {39    t.deepEqual({a: 1}, {a: 1});40});41test('deep equality', t => {42    t.deepEqual({a: 1}, {a: 1});43});44test('not deep equality', t => {45    t.notDeepEqual({a: 1}, {a: 2});46});47test('not deep equality', t => {48    t.notDeepEqual({a: 1}, {a: 2});49});50test('truthy value', t => {51    t.truthy('hello');52});53test('truthy value', t => {54    t.truthy('hello');55});56test('falsy value', t => {57    t.falsy('');58});

Using AI Code Generation

1const test = require('ava')2const fn = require('./')3test('throws on non-string', t => {4  t.throws(() => {5    fn(1)6  })7})8module.exports = function (str) {9  if (typeof str !== 'string') {10    throw new Error('Expected a string')11  }12}13### `t.throwsAsync(fn, [error, [message]])`14const test = require('ava')15const fn = require('./')16test('rejects with a TypeError', async t => {17  await t.throwsAsync(fn(1), TypeError)18})19test('rejects with a TypeError containing message', async t => {20  const error = await t.throwsAsync(fn(1), TypeError)21  t.is(error.message, 'Expected a string')22})23test('rejects with a TypeError matching message', async t => {24  await t.throwsAsync(fn(1), TypeError, 'Expected a string')25})26test('rejects with a TypeError matching message using regex', async t => {27  await t.throwsAsync(fn(1), TypeError, /string/)28})29test('rejects with a TypeError matching message using function', async t => {30  await t.throwsAsync(fn(1), TypeError, error => error.message === 'Expected a string')31})

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