init

Kent C. Dodds · Kent C. Dodds · commit 548e3717db7b · 2018-06-11T23:14:28.000-06:00
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1 @@
+node_modules
diff --git a/README.md b/README.md
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+<h1 align="center">
+  JavaScript Testing Fundamentals
+</h1>
+
+<p align="center" style="font-size: 1.2rem;">
+  Learn how automated JavaScript testing works by building your own framework!
+</p>
+
+<hr />
+
+Order of material:
+
+1.  `simple.js`
+2.  `assertion-library.js`
+3.  `testing-framework.js`
+4.  `async-await.js`
+5.  `globals.js`
+6.  `jest.test.js`
+
+The files are intended to test the `math` module.
+
+To run the files, run `node lessons/<lesson-filename>.js`.
+
+> For the `global` one, run `node -r ./setup-globals.js ./lessons/globals.js`
+> For the `jest.test.js` one, run `npx jest`.
diff --git a/lessons/assertion-library.js b/lessons/assertion-library.js
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+const {sum, subtract} = require('../math')
+
+let result, expected
+
+result = sum(3, 7)
+expected = 10
+expect(result).toBe(expected)
+
+result = subtract(7, 3)
+expected = 4
+expect(result).toBe(expected)
+
+function expect(actual) {
+  return {
+    toBe(expected) {
+      if (actual !== expected) {
+        throw new Error(`${actual} is not equal to ${expected}`)
+      }
+    }
+  }
+}
diff --git a/lessons/async-await.js b/lessons/async-await.js
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+const {sumAsync, subtractAsync} = require('../math')
+
+test('sumAsync adds numbers asynchronously', async () => {
+  const result = await sumAsync(3, 7)
+  const expected = 10
+  expect(result).toBe(expected)
+})
+
+test('subtractAsync subtracts numbers asynchronously', async () => {
+  const result = await subtractAsync(7, 3)
+  const expected = 4
+  expect(result).toBe(expected)
+})
+
+async function test(title, callback) {
+  try {
+    await callback()
+    console.log(`✓ ${title}`)
+  } catch (error) {
+    console.error(`✕ ${title}`)
+    console.error(error)
+  }
+}
+
+function expect(actual) {
+  return {
+    toBe(expected) {
+      if (actual !== expected) {
+        throw new Error(`${actual} is not equal to ${expected}`)
+      }
+    }
+  }
+}
diff --git a/lessons/globals.js b/lessons/globals.js
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+const {sumAsync, subtractAsync} = require('../math')
+
+test('sumAsync adds numbers asynchronously', async () => {
+  const result = await sumAsync(3, 7)
+  const expected = 10
+  expect(result).toBe(expected)
+})
+
+test('subtractAsync subtracts numbers asynchronously', async () => {
+  const result = await subtractAsync(7, 3)
+  const expected = 4
+  expect(result).toBe(expected)
+})
diff --git a/lessons/jest.test.js b/lessons/jest.test.js
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+const {sumAsync, subtractAsync} = require('../math')
+
+test('sumAsync adds numbers asynchronously', async () => {
+  const result = await sumAsync(3, 7)
+  const expected = 10
+  expect(result).toBe(expected)
+})
+
+test('subtractAsync subtracts numbers asynchronously', async () => {
+  const result = await subtractAsync(7, 3)
+  const expected = 4
+  expect(result).toBe(expected)
+})
diff --git a/lessons/simple.js b/lessons/simple.js
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+const {sum, subtract} = require('../math')
+
+let result, expected
+
+result = sum(3, 7)
+expected = 10
+if (result !== expected) {
+  throw new Error(`${result} is not equal to ${expected}`)
+}
+
+result = subtract(7, 3)
+expected = 4
+if (result !== expected) {
+  throw new Error(`${result} is not equal to ${expected}`)
+}
diff --git a/lessons/testing-framework.js b/lessons/testing-framework.js
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+const {sum, subtract} = require('../math')
+
+test('sum adds numbers', () => {
+  const result = sum(3, 7)
+  const expected = 10
+  expect(result).toBe(expected)
+})
+
+test('subtract subtracts numbers', () => {
+  const result = subtract(7, 3)
+  const expected = 4
+  expect(result).toBe(expected)
+})
+
+function test(title, callback) {
+  try {
+    callback()
+    console.log(`✓ ${title}`)
+  } catch (error) {
+    console.error(`✕ ${title}`)
+    console.error(error)
+  }
+}
+
+function expect(actual) {
+  return {
+    toBe(expected) {
+      if (actual !== expected) {
+        throw new Error(`${actual} is not equal to ${expected}`)
+      }
+    }
+  }
+}
diff --git a/math.js b/math.js
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+// sum is intentionally broken so you can see errors in the tests
+const sum = (a, b) => a - b
+const subtract = (a, b) => a - b
+
+// these are kinda pointless I know, but it's just to simulate an async function
+const sumAsync = (...args) => Promise.resolve(sum(...args))
+const subtractAsync = (...args) => Promise.resolve(subtract(...args))
+
+module.exports = {sum, subtract, sumAsync, subtractAsync}
diff --git a/package.json b/package.json
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+{
+  "name": "js-testing-fundamentals",
+  "version": "1.0.0",
+  "description": "A repo for my JavaScript Testing Fundamentals course",
+  "scripts": {
+    "test": "jest"
+  },
+  "keywords": [],
+  "author": "Kent C. Dodds <kent@doddsfamily.us> (http://kentcdodds.com/)",
+  "license": "MIT",
+  "devDependencies": {
+    "jest": "^23.1.0"
+  }
+}
diff --git a/setup-globals.js b/setup-globals.js
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+async function test(title, callback) {
+  try {
+    await callback()
+    console.log(`✓ ${title}`)
+  } catch (error) {
+    console.error(`✕ ${title}`)
+    console.error(error)
+  }
+}
+
+function expect(actual) {
+  return {
+    toBe(expected) {
+      if (actual !== expected) {
+        throw new Error(`${actual} is not equal to ${expected}`)
+      }
+    }
+  }
+}
+
+global.test = test
+global.expect = expect
