Convert pre-modules exercises to stdout-based testing

Author: kentcdodds

exercises/01.expressions-and-output/01.solution.hello-world/index.test.ts

@@ -3,15 +3,16 @@ import { execSync } from 'node:child_process'
 import { test } from 'node:test'
 
 await test('should print Hello, World!', () => {
-	const output = execSync('node index.ts', { encoding: 'utf8' })
 	assert.ok(
-		output.includes('Hello, World!'),
+		execSync('npm start --silent', { encoding: 'utf8' }).includes(
+			'Hello, World!',
+		),
 		'🚨 Output should include "Hello, World!" - make sure you used console.log() with that exact string',
 	)
 })
 
 await test('should print at least two lines', () => {
-	const output = execSync('node index.ts', { encoding: 'utf8' })
+	const output = execSync('npm start --silent', { encoding: 'utf8' })
 	const lines = output.trim().split('\n').filter(Boolean)
 	assert.ok(
 		lines.length >= 2,

exercises/01.expressions-and-output/02.problem.escaping-strings/index.ts

@@ -12,3 +12,12 @@
 
 // 🐨 Log tab-separated data: Name: [tab] Age: [tab] City: (like column headers)
 // 💰 Use \t to create tabs between words
+
+// 🐨 When you're done, uncomment this and update the values:
+// const results = {
+// 	apostrophe: "It's working!",
+// 	quotes: 'She said "Hi"',
+// 	newlines: 'Hello\nWorld',
+// 	tabs: 'Name:\tAge:\tCity:',
+// }
+// console.log('Results JSON:', JSON.stringify(results))

exercises/01.expressions-and-output/02.solution.escaping-strings/index.test.ts

@@ -2,34 +2,39 @@ import assert from 'node:assert/strict'
 import { execSync } from 'node:child_process'
 import { test } from 'node:test'
 
+const output = execSync('npm start --silent', { encoding: 'utf8' })
+const jsonLine = output
+	.split('\n')
+	.find((line) => line.startsWith('Results JSON:'))
+assert.ok(jsonLine, '🚨 Missing "Results JSON:" output line')
+const { apostrophe, quotes, newlines, tabs } = JSON.parse(
+	jsonLine.replace('Results JSON:', '').trim(),
+)
+
 await test('should print string with apostrophe', () => {
-	const output = execSync('node index.ts', { encoding: 'utf8' })
 	assert.ok(
-		output.includes("It's working!"),
+		apostrophe === "It's working!",
 		'🚨 Output should include "It\'s working!" - make sure you escaped the apostrophe',
 	)
 })
 
 await test('should print string with quotes', () => {
-	const output = execSync('node index.ts', { encoding: 'utf8' })
 	assert.ok(
-		output.includes('She said "Hi"'),
+		quotes === 'She said "Hi"',
 		'🚨 Output should include: She said "Hi" - make sure you escaped the double quotes',
 	)
 })
 
 await test('should print Hello and World on separate lines', () => {
-	const output = execSync('node index.ts', { encoding: 'utf8' })
 	assert.ok(
-		output.includes('Hello\nWorld'),
+		newlines === 'Hello\nWorld',
 		'🚨 Output should include "Hello" and "World" on separate lines - use \\n in a single string',
 	)
 })
 
 await test('should print tab-separated values', () => {
-	const output = execSync('node index.ts', { encoding: 'utf8' })
 	assert.ok(
-		output.includes('\t'),
+		tabs.includes('\t'),
 		'🚨 Output should include tab characters - make sure you used \\t for tabs',
 	)
 })

exercises/01.expressions-and-output/02.solution.escaping-strings/index.ts

@@ -2,13 +2,22 @@
 // Learn to include special characters in strings
 
 // prettier-ignore
-console.log('It\'s working!')
+const apostrophe = 'It\'s working!'
+console.log(apostrophe)
 
 // prettier-ignore
-console.log("She said \"Hi\"")
+const quotes = "She said \"Hi\""
+console.log(quotes)
 
 // prettier-ignore
-console.log('Hello\nWorld')
+const newlines = 'Hello\nWorld'
+console.log(newlines)
 
 // prettier-ignore
-console.log('Name:\tAge:\tCity:')
+const tabs = 'Name:\tAge:\tCity:'
+console.log(tabs)
+
+console.log(
+	'Results JSON:',
+	JSON.stringify({ apostrophe, quotes, newlines, tabs }),
+)

exercises/01.expressions-and-output/03.problem.strings/index.ts

@@ -7,3 +7,11 @@
 
 // 🐨 Log a sentence by concatenating multiple strings
 // 💰 Example: "I" + " " + "am" + " " + "learning" + " " + "to" + " " + "code"
+
+// 🐨 When you're done, uncomment this and update the values:
+// const results = {
+// 	greeting: 'Hello TypeScript',
+// 	fullName: 'Your Name',
+// 	sentence: 'I am learning to code',
+// }
+// console.log('Results JSON:', JSON.stringify(results))

exercises/01.expressions-and-output/03.solution.strings/index.test.ts

@@ -3,16 +3,21 @@ import { execSync } from 'node:child_process'
 import { readFileSync } from 'node:fs'
 import { test } from 'node:test'
 
+const output = execSync('npm start --silent', { encoding: 'utf8' })
+const jsonLine = output
+	.split('\n')
+	.find((line) => line.startsWith('Results JSON:'))
+assert.ok(jsonLine, '🚨 Missing "Results JSON:" output line')
+const { greeting } = JSON.parse(jsonLine.replace('Results JSON:', '').trim())
+
 await test('should print Hello TypeScript', () => {
-	const output = execSync('node index.ts', { encoding: 'utf8' })
 	assert.ok(
-		output.includes('Hello TypeScript'),
+		greeting === 'Hello TypeScript',
 		'🚨 Output should include "Hello TypeScript" - concatenate "Hello" + " " + "TypeScript"',
 	)
 })
 
 await test('should print at least three lines', () => {
-	const output = execSync('node index.ts', { encoding: 'utf8' })
 	const lines = output.trim().split('\n').filter(Boolean)
 	assert.ok(
 		lines.length >= 3,

exercises/01.expressions-and-output/03.solution.strings/index.ts

@@ -1,8 +1,11 @@
 // String Expressions
 // Learn to work with text data
 
-console.log('Hello' + ' ' + 'TypeScript')
+const greeting = 'Hello' + ' ' + 'TypeScript'
+const fullName = 'Kody' + ' ' + 'Koala'
+const sentence = 'I' + ' ' + 'am' + ' ' + 'learning' + ' ' + 'to' + ' ' + 'code'
 
-console.log('Kody' + ' ' + 'Koala')
-
-console.log('I' + ' ' + 'am' + ' ' + 'learning' + ' ' + 'to' + ' ' + 'code')
+console.log(greeting)
+console.log(fullName)
+console.log(sentence)
+console.log('Results JSON:', JSON.stringify({ greeting, fullName, sentence }))

exercises/01.expressions-and-output/04.problem.numbers/index.ts

@@ -9,3 +9,12 @@
 
 // 🐨 Use console.log to show the result of (10 + 5) multiplied by 2
 // 💰 Use parentheses to control order of operations
+
+// 🐨 When you're done, uncomment this and update the values:
+// const results = {
+// 	addResult: 42,
+// 	multiplyResult: 48,
+// 	divideResult: 25,
+// 	groupedResult: 30,
+// }
+// console.log('Results JSON:', JSON.stringify(results))

exercises/01.expressions-and-output/04.solution.numbers/index.test.ts

@@ -2,29 +2,35 @@ import assert from 'node:assert/strict'
 import { execSync } from 'node:child_process'
 import { test } from 'node:test'
 
-await test('should print correct arithmetic results', () => {
-	const output = execSync('node index.ts', { encoding: 'utf8' })
+const output = execSync('npm start --silent', { encoding: 'utf8' })
+const jsonLine = output
+	.split('\n')
+	.find((line) => line.startsWith('Results JSON:'))
+assert.ok(jsonLine, '🚨 Missing "Results JSON:" output line')
+const { addResult, multiplyResult, divideResult, groupedResult } = JSON.parse(
+	jsonLine.replace('Results JSON:', '').trim(),
+)
 
+await test('should print correct arithmetic results', () => {
 	assert.ok(
-		output.includes('42'),
+		addResult === 42,
 		'🚨 Output should include 42 (the result of 25 + 17)',
 	)
 	assert.ok(
-		output.includes('48'),
+		multiplyResult === 48,
 		'🚨 Output should include 48 (the result of 8 * 6)',
 	)
 	assert.ok(
-		output.includes('25'),
+		divideResult === 25,
 		'🚨 Output should include 25 (the result of 100 / 4)',
 	)
 	assert.ok(
-		output.includes('30'),
+		groupedResult === 30,
 		'🚨 Output should include 30 (the result of (10 + 5) * 2)',
 	)
 })
 
 await test('should print at least four lines', () => {
-	const output = execSync('node index.ts', { encoding: 'utf8' })
 	const lines = output.trim().split('\n').filter(Boolean)
 	assert.ok(
 		lines.length >= 4,

exercises/01.expressions-and-output/04.solution.numbers/index.ts

@@ -1,10 +1,16 @@
 // Number Expressions
 // Learn arithmetic operations
 
-console.log(25 + 17)
+const addResult = 25 + 17
+const multiplyResult = 8 * 6
+const divideResult = 100 / 4
+const groupedResult = (10 + 5) * 2
 
-console.log(8 * 6)
-
-console.log(100 / 4)
-
-console.log((10 + 5) * 2)
+console.log(addResult)
+console.log(multiplyResult)
+console.log(divideResult)
+console.log(groupedResult)
+console.log(
+	'Results JSON:',
+	JSON.stringify({ addResult, multiplyResult, divideResult, groupedResult }),
+)