Thinking about how a test library works I decided to create my own test library using TypeScript, taking inspiration from the functionality and design of existing libraries such as Jest. The code is available for anyone to clone and learn from.
Clone the project
git clone https://github.com/Andre0n/vtestGo to the project directory
cd vtestInstall dependencies
npm installCompiling the code
npm run buildnpm test- Create a basic test suite
const vtest = require('./vtest');
const my_suite = new vtest.TestSuite("Test Suite Example");- Use the function
add_testto create a new test
my_suite.add_test("1 + 1 should be 2");- This function returns the
expect()function that returns matchers liketoBe()that compares whether two elements are equals.
my_suite
.add_test(" 1 + 1 should be 2")
.expect(() => {
return 1 + 1;
})
.toBe(2);
my_suite
.add_test(" 'aabb' == 'aabb' ")
.expect(() => {
return "aabb";
})
.toBe("aabb");- The
toBehas a variant thenotBe
my_suite
.add_test("2 - 1 should not be 3")
.expect(() => {
return 2 - 1;
})
.notBe(3);- The
toBeDefined
my_suite
.add_test("check if was defined")
.expect(() => {
return {};
})
.toBeDefined();- The
toBeCloseTo
my_suite
.add_test("check if 0.1 + 0.2 is close to 0.3")
.expect(() => {
return 0.1 + 0.2;
})
.toBeCloseTo(0.3);- The
toBeNull
my_suite
.add_test("check if is null")
.expect(() => {
return null;
})
.toBeNull();- The
notBeNull
my_suite
.add_test("check if is not null")
.expect(() => {
return null;
})
.notBeNull();To print test results the TestSuite object has the report() method.
my_suite.report();Our example will produce the following result
Test Suite Example
✔ 1 + 1 should be 2
✔ 'aabb' == 'aabb'
✔ 2 - 1 should not be 3
✔ check if was defined
✔ check if 0.1 + 0.2 is close to 0.3
✔ check if is null
✖ check if is not null notBeNull: The object is null
>> Expected: any Got: null <<
Tests: Passed: 6, Failed: 1, Total: 7
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