Testing TypeScript Code

Simple Assertions

A small assertion helper can compare actual and expected values during a test.

Simple Assertions

assertions.ts 
function addTax(cents: number, rate: number): number {
    return Math.round(cents * (1 + rate));
}

function assertEqual(actual: number, expected: number): boolean {
    return actual === expected;
}

const rate: number = ;
const actual: number = addTax(1000, rate);
const expected: number = rate === 0.10 ? 1100 : 1200;
const passed: boolean = assertEqual(actual, expected);

console.log(passed ? `pass:${actual}` : `fail:${actual}`);

function addTax(cents: number, rate: number): number {
    return Math.round(cents * (1 + rate));
}

function assertEqual(actual: number, expected: number): boolean {
    return actual === expected;
}

const rate: number = ;
const actual: number = addTax(1000, rate);
const expected: number = rate === 0.10 ? 1100 : 1200;
const passed: boolean = assertEqual(actual, expected);

console.log(passed ? `pass:${actual}` : `fail:${actual}`);
assertion An assertion turns a condition into a pass or fail result that can be counted and reported.