仅在结果不是对象/数组的情况下，才能对导入的模块进行打字稿单元测试

Question

I am trying to learn/understand how to do unit testing on typescript code and am running into an issue that I simply do not understand.

If I import modules into my test.ts file, the tests will run fine but only pass if the result is NOT an object or array. In those cases, the test will fail and tell me:

AssertionError: expected { greeting: 'Hello' } to equal { greeting: 'Hello' }

Code:

hello.ts:

 export function helloString() { return "Hello"; } export function helloObject() { return {greeting: "Hello"} } export function helloArray() { return ["Hello"] } 

test.ts:

 import { helloString, helloObject, helloArray } from "./hello"; import { expect } from "chai" describe("Hello string function", () => { it("should return hello", () => { const result = helloString(); expect(result).to.equal("Hello"); }) }) describe("Hello object function", () => { it("should return hello", () => { const result = helloObject(); expect(result).to.equal({greeting: "Hello"}); }) }) describe("Hello array function", () => { it("should return hello", () => { const result = helloArray(); expect(result).to.equal(["Hello"]); }) }) 

package.json:

 { "name": "typescriptTesting", "version": "1.0.0", "main": "index.js", "license": "MIT", "scripts": { "test": "mocha -r ts-node/register src/test.ts" }, "devDependencies": { "@types/chai": "^3.4.35", "@types/mocha": "^2.2.39", "chai": "^3.5.0", "mocha": "^3.2.0", "ts-node": "^2.1.0", "typescript": "^2.2.1" } } 

github repo: https://github.com/llanginger/typescriptUnitTestsIssue

I imagine that there's something simple I'm missing here, but having worked through multiple examples of "typescript unit testing" tutorials using everything from a gulp suite to karma/sinon etc. The result is always the same - if I import a function that returns an object or array, the test will fail while presenting case-passing results. Any help would be much appreciated!

Answer 1

Since you're using expect you will want to user .deep to evaluate object equality:

expect(foo).to.deep.equal({ bar: 'baz' });

Link: http://chaijs.com/api/bdd/#method_deep

If you choose to also use assert with chai then you can use .deepEqual :

assert.deepEqual({ tea: 'green' }, { tea: 'green' });

Link: http://chaijs.com/api/assert/#method_deepequal