Initial commit with several TDD TypeScript examples

Author: burus86

.gitignore

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+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+
+# Diagnostic reports (https://nodejs.org/api/report.html)
+report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+*.lcov
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (https://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (https://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+jspm_packages/
+
+# TypeScript v1 declaration files
+typings/
+
+# TypeScript cache
+*.tsbuildinfo
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Microbundle cache
+.rpt2_cache/
+.rts2_cache_cjs/
+.rts2_cache_es/
+.rts2_cache_umd/
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variables file
+.env
+.env.test
+
+# parcel-bundler cache (https://parceljs.org/)
+.cache
+
+# Next.js build output
+.next
+
+# Nuxt.js build / generate output
+.nuxt
+dist
+
+# Gatsby files
+.cache/
+# Comment in the public line in if your project uses Gatsby and *not* Next.js
+# https://nextjs.org/blog/next-9-1#public-directory-support
+# public
+
+# vuepress build output
+.vuepress/dist
+
+# Serverless directories
+.serverless/
+
+# FuseBox cache
+.fusebox/
+
+# DynamoDB Local files
+.dynamodb/
+
+# TernJS port file
+.tern-port

.prettierignore

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+# compiled output
+/bin
+/dist
+/tmp
+/out-tsc
+
+# dependencies
+/node_modules
+
+# misc
+/.sass-cache
+/connect.lock
+/coverage
+npm-debug.log
+yarn-error.log
+/typings
+
+# misc
+/.sass-cache
+/connect.lock
+/coverage
+npm-debug.log
+yarn-error.log
+testem.log
+/typings

.prettierrc.json

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+{
+  "arrowParens": "avoid",
+  "bracketSpacing": true,
+  "jsxBracketSameLine": true,
+  "printWidth": 80,
+  "proseWrap": "preserve",
+  "semi": true,
+  "singleQuote": true,
+  "tabWidth": 2,
+  "trailingComma": "es5",
+  "useTabs": false
+}

.vscode/extensions.json

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+{
+  "recommendations": [
+    "esbenp.prettier-vscode",
+    "dbaeumer.vscode-eslint",
+    "pkief.material-icon-theme",
+    "christian-kohler.path-intellisense",
+    "streetsidesoftware.code-spell-checker"
+  ]
+}

.vscode/settings.json

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+{
+  "[javascript]": {
+    "editor.defaultFormatter": "esbenp.prettier-vscode"
+  },
+  "[typescript]": {
+    "editor.defaultFormatter": "esbenp.prettier-vscode"
+  },
+  "editor.formatOnSave": true,
+  "editor.defaultFormatter": "esbenp.prettier-vscode",
+  "editor.formatOnType": true,
+  "typescript.format.insertSpaceAfterTypeAssertion": true,
+  "cSpell.words": ["codepaths", "Fizzbuzz", "tsbuildinfo"]
+}

.vscode/ts-jst-snippets.json

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+{
+  "Jest Describe It": {
+    "prefix": "ab-jst-dit",
+    "body": [
+      "describe('$1', () => {",
+      "  let sut;",
+      "  beforeEach(() => {",
+      "    // Arrange",
+      "    sut = null;",
+      "  });",
+      "  it('should $2', () => {",
+      "    // Act",
+      "    const actual = null;",
+      "    // Assert",
+      "    const expected = null;",
+      "    expect(actual).toStrictEqual(expected);",
+      "  });",
+      "});"
+    ],
+    "description": "Describe It Should with Jest"
+  },
+  "Jest It": {
+    "prefix": "ab-jst-it",
+    "body": [
+      "it('should $2', () => {",
+      "  const sut = null;",
+      "  const actual = null;",
+      "  const expected = null;",
+      "  expect(actual).toBe(expected);",
+      "});"
+    ],
+    "description": "It Should with Jest"
+  }
+}

LICENSE

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+MIT License
+
+Copyright (c) 2021 Juan Jesús Gómez Noya
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+# tdd-typescript-jest
+
+Test driven development with Jest and Typescript
+
+```bash
+# Git clone and use as is
+git clone https://github.com/burus86/tdd-typescript-jest.git
+cd tdd-typescript-jest
+npm i
+npm test
+
+# Alternatively, start from empty folder
+
+npm i -D typescript jest
+npm i -D @types/node @types/jest
+npm i -D ts-jest
+npx ts-jest config:init
+npx tsc --init
+```

docs/0-intro-tdd.md

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+# 0 - Intro TDD
+
+## TDD is testing
+
+### Tools: Jest
+
+- Test runner
+- Assertion library
+- Testing framework
+
+### Syntax
+
+```ts
+describe('the subject under test', () => {
+  let sut;
+  beforeEach(() => {
+    // Arrange
+    sut = undefined;
+  });
+  it('should do something', () => {
+    // Act
+    const actual = undefined;
+    // Assert
+    const expected = undefined;
+    expect(actual).toStrictEqual(expected);
+  });
+});
+```
+
+## TDD is a coding discipline
+
+### Test before
+
+- If you write your tests before you are forced to think and have a better understanding.
+- If you write your tests before you will have a functional documentation for free.
+- If you write your tests before your objects wil have a more convenient API.
+- If you write your tests before your code will be easier to maintain.
+- If you write your tests before... you always write tests.
+
+### Red Green Refactor
+
+- ❌ Red: Write a test and see it failing
+- ✔️ Green: Write the minimum code that makes the test pass
+- 🔵 Refactor: Write a cleaner or more efficient implementation
+
+> 🚧 Some people considere a yellow step when test does not compile yet
+
+### Unit, integration, e2e
+
+- Can be used for any kind of tests... but
+- In my opinion TDD is better suited to unit testing complex clases or functions
+
+## TDD timings
+
+- Initially it takes longer to get things done
+- Reduces debugging times in the medium term
+- Start small and take baby steps
+- Test should be really fast

docs/1-tdd-sources.md

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+# 1 - TDD sources
+
+## From explicit rules
+
+- Easiest scenario
+- Test each rule with samples
+
+## From examples
+
+- Could be hard or at least time consuming
+- The algorithm emerges providing more and more samples
+
+## From vague requirements
+
+- Not desiderable but common
+- Forces you to ask more detailed questions

docs/2-tdd-domains.md

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+# 2 - TDD domains
+
+## The core knowledge
+
+- What it is important
+
+## A description of the real world
+
+- Higher level rules, not implementation details
+
+## Incremental value
+
+- Evolving functionality and solving issues

jest.config.js

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+/** @type {import('ts-jest/dist/types').InitialOptionsTsJest} */
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+};