自動化測試是工程師基本要求。
Last updated
<!DOCTYPE html>
<html>
<head>
<!-- add mocha css, to show results -->
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/mocha/3.2.0/mocha.css">
<!-- add mocha framework code -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/mocha/3.2.0/mocha.js"></script>
<script>
mocha.setup('bdd'); // minimal setup
</script>
<!-- add chai -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/chai/3.5.0/chai.js"></script>
<script>
// chai has a lot of stuff, let's make assert global
let assert = chai.assert;
</script>
</head>
<body>
<script>
function pow(x, n) {
/* function code is to be written, empty now */
}
</script>
<!-- the script with tests (describe, it...) -->
<script src="test.js"></script>
<!-- the element with id="mocha" will contain test results -->
<div id="mocha"></div>
<!-- run tests! -->
<script>
mocha.run();
</script>
</body>
</html>// method1
describe("pow", function() {
it("raises to n-th power", function() {
assert.equal(pow(2, 3), 8);
assert.equal(pow(3, 4), 81);
});
});
// method2 better
describe("pow", function() {
it("2 raised to power 3 is 8", function() {
assert.equal(pow(2, 3), 8);
});
it("3 raised to power 3 is 27", function() {
assert.equal(pow(3, 3), 27);
});
});function pow(x, n) {
let result = 1;
for (let i = 0; i < n; i++) {
result *= x;
}
return result;
}
// test
describe("pow", function() {
function makeTest(x) {
let expected = x * x * x;
it(`${x} in the power 3 is ${expected}`, function() {
assert.equal(pow(x, 3), expected);
});
}
for (let x = 1; x <= 5; x++) {
makeTest(x);
}
});describe("pow", function() {
describe("raises x to power 3", function() {
function makeTest(x) {
let expected = x * x * x;
it(`${x} in the power 3 is ${expected}`, function() {
assert.equal(pow(x, 3), expected);
});
}
for (let x = 1; x <= 5; x++) {
makeTest(x);
}
});
// ... more tests to follow here, both describe and it can be added
});describe("test", function() {
before(() => alert("Testing started – before all tests"));
after(() => alert("Testing finished – after all tests"));
beforeEach(() => alert("Before a test – enter a test"));
afterEach(() => alert("After a test – exit a test"));
it('test 1', () => alert(1));
it('test 2', () => alert(2));
});
// result
Testing started – before all tests (before)
Before a test – enter a test (beforeEach)
1
After a test – exit a test (afterEach)
Before a test – enter a test (beforeEach)
2
After a test – exit a test (afterEach)
Testing finished – after all tests (after)// add spec
describe("pow", function() {
// ...
it("for negative n the result is NaN", function() {
assert.isNaN(pow(2, -1));
});
it("for non-integer n the result is NaN", function() {
assert.isNaN(pow(2, 1.5));
});
});
// improve pow(x ,n)
function pow(x, n) {
if (n < 0) return NaN;
if (Math.round(n) != n) return NaN;
let result = 1;
for (let i = 0; i < n; i++) {
result *= x;
}
return result;
}