Best JavaScript code snippet using jest
node.test.js
Source: node.test.js
...85 '/fruits/strawberry.js',86 '/fruits/tomato.js',87 '/vegetables/melon.json',88 ].join('\n');89 const promise = nodeCrawl({90 data: {91 files: Object.create(null),92 },93 extensions: ['js', 'json'],94 ignore: pearMatcher,95 roots: ['/fruits', '/vegtables'],96 }).then(data => {97 expect(childProcess.spawn).lastCalledWith('find', [98 '/fruits',99 '/vegtables',100 '-type',101 'f',102 '(',103 '-iname',104 '*.js',105 '-o',106 '-iname',107 '*.json',108 ')',109 ]);110 expect(data.files).not.toBe(null);111 expect(data.files).toEqual({112 '/fruits/strawberry.js': ['', 32, 0, []],113 '/fruits/tomato.js': ['', 33, 0, []],114 '/vegetables/melon.json': ['', 34, 0, []],115 });116 });117 return promise;118 });119 it('updates only changed files', () => {120 process.platform = 'linux';121 nodeCrawl = require('../node');122 const files = Object.create(null);123 // In this test sample, strawberry is changed and tomato is unchanged124 const tomato = ['', 33, 1, []];125 files['/fruits/strawberry.js'] = ['', 30, 1, []];126 files['/fruits/tomato.js'] = tomato;127 return nodeCrawl({128 data: {files},129 extensions: ['js'],130 ignore: pearMatcher,131 roots: ['/fruits'],132 }).then(data => {133 expect(data.files).toEqual({134 '/fruits/strawberry.js': ['', 32, 0, []],135 '/fruits/tomato.js': tomato,136 });137 // Make sure it is the *same* unchanged object.138 expect(data.files['/fruits/tomato.js']).toBe(tomato);139 });140 });141 it('uses node fs APIs on windows', () => {142 process.platform = 'win32';143 nodeCrawl = require('../node');144 const files = Object.create(null);145 return nodeCrawl({146 data: {files},147 extensions: ['js'],148 ignore: pearMatcher,149 roots: ['/fruits'],150 }).then(data => {151 expect(data.files).toEqual({152 '/fruits/directory/strawberry.js': ['', 33, 0, []],153 '/fruits/tomato.js': ['', 32, 0, []],154 });155 });156 });157 it('uses node fs APIs if "forceNodeFilesystemAPI" is set to true, regardless of platform', () => {158 process.platform = 'linux';159 nodeCrawl = require('../node');160 const files = Object.create(null);161 return nodeCrawl({162 data: {files},163 extensions: ['js'],164 forceNodeFilesystemAPI: true,165 ignore: pearMatcher,166 roots: ['/fruits'],167 }).then(data => {168 expect(data.files).toEqual({169 '/fruits/directory/strawberry.js': ['', 33, 0, []],170 '/fruits/tomato.js': ['', 32, 0, []],171 });172 });173 });174 it('completes with empty roots', () => {175 process.platform = 'win32';176 nodeCrawl = require('../node');177 const files = Object.create(null);178 return nodeCrawl({179 data: {files},180 extensions: ['js'],181 forceNodeFilesystemAPI: true,182 ignore: pearMatcher,183 roots: [],184 }).then(data => {185 expect(data.files).toEqual({});186 });187 });...
node-test.js
Source: node-test.js
...88 '/fruits/strawberry.js',89 '/fruits/tomato.js',90 '/vegetables/melon.json',91 ].join('\n');92 const promise = nodeCrawl({93 data: {94 files: Object.create(null),95 },96 extensions: ['js', 'json'],97 ignore: pearMatcher,98 roots: ['/fruits', '/vegtables'],99 }).then(data => {100 expect(childProcess.spawn).lastCalledWith('find', [101 '/fruits',102 '/vegtables',103 '-type',104 'f',105 '\(',106 '-iname',107 '*.js',108 '-o',109 '-iname',110 '*.json',111 '\)',112 ]);113 expect(data.files).not.toBe(null);114 expect(data.files).toEqual({115 '/fruits/strawberry.js': ['', 32, 0, []],116 '/fruits/tomato.js': ['', 33, 0, []],117 '/vegetables/melon.json': ['', 34, 0, []],118 });119 });120 return promise;121 });122 it('updates only changed files', () => {123 process.platform = 'linux';124 nodeCrawl = require('../node');125 const files = Object.create(null);126 // In this test sample, strawberry is changed and tomato is unchanged127 const tomato = ['', 33, 1, []];128 files['/fruits/strawberry.js'] = ['', 30, 1, []];129 files['/fruits/tomato.js'] = tomato;130 return nodeCrawl({131 data: {files},132 extensions: ['js'],133 ignore: pearMatcher,134 roots: ['/fruits'],135 }).then(data => {136 expect(data.files).toEqual({137 '/fruits/strawberry.js': ['', 32, 0, []],138 '/fruits/tomato.js': tomato,139 });140 // Make sure it is the *same* unchanged object.141 expect(data.files['/fruits/tomato.js']).toBe(tomato);142 });143 });144 it('uses node fs APIs on windows', () => {145 process.platform = 'win32';146 nodeCrawl = require('../node');147 const files = Object.create(null);148 return nodeCrawl({149 data: {files},150 extensions: ['js'],151 ignore: pearMatcher,152 roots: ['/fruits'],153 }).then(data => {154 expect(data.files).toEqual({155 '/fruits/directory/strawberry.js': ['', 33, 0, []],156 '/fruits/tomato.js': ['', 32, 0, []],157 });158 });159 });160 it('uses node fs APIs if "forceNodeFilesystemAPI" is set to true, regardless of platform', () => {161 process.platform = 'linux';162 nodeCrawl = require('../node');163 const files = Object.create(null);164 return nodeCrawl({165 data: {files},166 extensions: ['js'],167 forceNodeFilesystemAPI: true,168 ignore: pearMatcher,169 roots: ['/fruits'],170 }).then(data => {171 expect(data.files).toEqual({172 '/fruits/directory/strawberry.js': ['', 33, 0, []],173 '/fruits/tomato.js': ['', 32, 0, []],174 });175 });176 });...
4875.js
Source: 4875.js
...17 "/fruits/strawberry.js",18 "/fruits/tomato.js",19 "/vegetables/melon.json"20 ].join("\n");21 const promise = nodeCrawl({22 data: {23 files: Object.create(null)24 },25 extensions: ["js", "json"],26 ignore: pearMatcher,27 roots: ["/fruits", "/vegtables"]28 }).then(data => {29 expect(childProcess.spawn).lastCalledWith("find", [30 "/fruits",31 "/vegtables",32 "-type",33 "f",34 "(",35 "-iname",36 "*.js",37 "-o",38 "-iname",39 "*.json",40 ")"41 ]);42 expect(data.files).not.toBe(null);43 expect(data.files).toEqual({44 "/fruits/strawberry.js": ["", 32, 0, []],45 "/fruits/tomato.js": ["", 33, 0, []],46 "/vegetables/melon.json": ["", 34, 0, []]47 });48 });49 return promise;50 });51 it("updates only changed files", () => {52 process.platform = "linux";53 nodeCrawl = require("../node");54 const files = Object.create(null);55 const tomato = ["", 33, 1, []];56 files["/fruits/strawberry.js"] = ["", 30, 1, []];57 files["/fruits/tomato.js"] = tomato;58 return nodeCrawl({59 data: {60 files61 },62 extensions: ["js"],63 ignore: pearMatcher,64 roots: ["/fruits"]65 }).then(data => {66 expect(data.files).toEqual({67 "/fruits/strawberry.js": ["", 32, 0, []],68 "/fruits/tomato.js": tomato69 });70 expect(data.files["/fruits/tomato.js"]).toBe(tomato);71 });72 });73 it("uses node fs APIs on windows", () => {74 process.platform = "win32";75 nodeCrawl = require("../node");76 const files = Object.create(null);77 return nodeCrawl({78 data: {79 files80 },81 extensions: ["js"],82 ignore: pearMatcher,83 roots: ["/fruits"]84 }).then(data => {85 expect(data.files).toEqual({86 "/fruits/directory/strawberry.js": ["", 33, 0, []],87 "/fruits/tomato.js": ["", 32, 0, []]88 });89 });90 });91 it('uses node fs APIs if "forceNodeFilesystemAPI" is set to true, regardless of platform', () => {92 process.platform = "linux";93 nodeCrawl = require("../node");94 const files = Object.create(null);95 return nodeCrawl({96 data: {97 files98 },99 extensions: ["js"],100 forceNodeFilesystemAPI: true,101 ignore: pearMatcher,102 roots: ["/fruits"]103 }).then(data => {104 expect(data.files).toEqual({105 "/fruits/directory/strawberry.js": ["", 33, 0, []],106 "/fruits/tomato.js": ["", 32, 0, []]107 });108 });109 });110 it("completes with emtpy roots", () => {111 process.platform = "win32";112 nodeCrawl = require("../node");113 const files = Object.create(null);114 return nodeCrawl({115 data: {116 files117 },118 extensions: ["js"],119 forceNodeFilesystemAPI: true,120 ignore: pearMatcher,121 roots: []122 }).then(data => {123 expect(data.files).toEqual({});124 });125 });...
index.js
Source: index.js
1'use strict';2const nodeCrawl = require('./node');3function crawl(roots, options) {4 return nodeCrawl(roots, options);5}...
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Since Jest tests are runtime tests, they only have access to runtime information. You're trying to use a type, which is compile-time information. TypeScript should already be doing the type aspect of this for you. (More on that in a moment.)
The fact the tests only have access to runtime information has a couple of ramifications:
If it's valid for getAll
to return an empty array (because there aren't any entities to get), the test cannot tell you whether the array would have had Entity
elements in it if it hadn't been empty. All it can tell you is it got an array.
In the non-empty case, you have to check every element of the array to see if it's an Entity
. You've said Entity
is a class, not just a type, so that's possible. I'm not a user of Jest (I should be), but it doesn't seem to have a test specifically for this; it does have toBeTruthy
, though, and we can use every
to tell us if every element is an Entity
:
it('should return an array of Entity class', async () => {
const all = await service.getAll()
expect(all.every(e => e instanceof Entity)).toBeTruthy();
});
Beware, though, that all calls to every
on an empty array return true
, so again, that empty array issue raises its head.
If your Jest tests are written in TypeScript, you can improve on that by ensuring TypeScript tests the compile-time type of getAll
's return value:
it('should return an array of Entity class', async () => {
const all: Entity[] = await service.getAll()
// ^^^^^^^^^^
expect(all.every(e => e instanceof Entity)).toBeTruthy();
});
TypeScript will complain about that assignment at compile time if it's not valid, and Jest will complain at runtime if it sees an array containing a non-Entity
object.
But jonrsharpe has a good point: This test may not be useful vs. testing for specific values that should be there.
Check out the latest blogs from LambdaTest on this topic:
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|<p>it('check_object_of_Car', () => {</p><p>
expect(newCar()).toBeInstanceOf(Car);</p><p>
});</p>|
| :- |
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