'use strict'; const common = require('../common'); const assert = require('assert'); const cares = process.binding('cares_wrap'); const dns = require('dns'); // Stub `getaddrinfo` to *always* error. cares.getaddrinfo = () => process.binding('uv').UV_ENOENT; assert.throws(() => { dns.lookup(1, {}); }, /^TypeError: Invalid arguments: hostname must be a string or falsey$/); assert.throws(() => { dns.lookup(false, 'cb'); }, /^TypeError: Invalid arguments: callback must be passed$/); assert.throws(() => { dns.lookup(false, 'options', 'cb'); }, /^TypeError: Invalid arguments: callback must be passed$/); assert.throws(() => { dns.lookup(false, { hints: 100, family: 0, all: false }, () => {}); }, /^TypeError: Invalid argument: hints must use valid flags$/); assert.throws(() => { dns.lookup(false, { hints: 0, family: 20, all: false }, () => {}); }, /^TypeError: Invalid argument: family must be 4 or 6$/); assert.doesNotThrow(() => { dns.lookup(false, { hints: 0, family: 0, all: true }, common.mustCall((error, result, addressType) => { assert.ifError(error); assert.deepStrictEqual(result, []); assert.strictEqual(addressType, undefined); })); }); assert.doesNotThrow(() => { dns.lookup('127.0.0.1', { hints: 0, family: 4, all: true }, common.mustCall((error, result, addressType) => { assert.ifError(error); assert.deepStrictEqual(result, [{ address: '127.0.0.1', family: 4 }]); assert.strictEqual(addressType, undefined); })); }); assert.doesNotThrow(() => { dns.lookup('127.0.0.1', { hints: 0, family: 4, all: false }, common.mustCall((error, result, addressType) => { assert.ifError(error); assert.deepStrictEqual(result, '127.0.0.1'); assert.strictEqual(addressType, 4); })); }); assert.doesNotThrow(() => { let tickValue = 0; dns.lookup('example.com', common.mustCall((error, result, addressType) => { assert(error); assert.strictEqual(tickValue, 1); assert.strictEqual(error.code, 'ENOENT'); })); // Make sure that the error callback is called // on next tick. tickValue = 1; });