Hello World

typescript/.gitignore

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+node_modules

typescript/hello-world/.eslintignore

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+!.meta
+
+# Protected or generated
+.git
+.vscode
+
+# When using npm
+node_modules/*
+
+# Configuration files
+.eslintrc.cjs
+babel.config.cjs
+jest.config.cjs

typescript/hello-world/.eslintrc.cjs

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+module.exports = {
+  root: true,
+  parserOptions: {
+    tsconfigRootDir: __dirname,
+    project: ['./tsconfig.json'],
+  },
+  overrides: [
+    // Student provided files
+    {
+      files: ['*.ts'],
+      excludedFiles: ['.meta/proof.ci.ts', '.meta/exemplar.ts', '*.test.ts'],
+      extends: '@exercism/eslint-config-typescript',
+    },
+    // Exercism given tests
+    {
+      files: ['*.test.ts'],
+      excludedFiles: ['custom.test.ts'],
+      env: {
+        jest: true,
+      },
+      extends: '@exercism/eslint-config-typescript/maintainers',
+    },
+    // Student provided tests
+    {
+      files: ['custom.test.ts'],
+      env: {
+        jest: true,
+      },
+      extends: '@exercism/eslint-config-typescript',
+    },
+    // Exercism provided files
+    {
+      files: ['.meta/proof.ci.ts', '.meta/exemplar.ts', '*.test.ts'],
+      excludedFiles: ['custom.test.ts'],
+      extends: '@exercism/eslint-config-typescript/maintainers',
+    },
+  ],
+}

typescript/hello-world/.exercism/config.json

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+{
+  "blurb": "The classical introductory exercise. Just say \"Hello, World!\"",
+  "authors": ["masters3d"],
+  "contributors": [
+    "DFXLuna",
+    "iHiD",
+    "kytrinyx",
+    "lukaszklis",
+    "porkostomus",
+    "SleeplessByte"
+  ],
+  "files": {
+    "solution": ["hello-world.ts"],
+    "test": ["hello-world.test.ts"],
+    "example": [".meta/proof.ci.ts"]
+  },
+  "source": "This is an exercise to introduce users to using Exercism",
+  "source_url": "http://en.wikipedia.org/wiki/%22Hello,_world!%22_program"
+}

typescript/hello-world/.exercism/metadata.json

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+{"track":"typescript","exercise":"hello-world","id":"982da4c4be0f4156b076dfb083369865","url":"https://exercism.org/tracks/typescript/exercises/hello-world","handle":"briemens","is_requester":true,"auto_approve":false}

typescript/hello-world/HELP.md

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+# Help
+
+## Running the tests
+
+Execute the tests with:
+
+```bash
+$ yarn test
+```
+
+## Skipped tests
+
+In the test suites all tests but the first have been skipped.
+
+Once you get a test passing, you can enable the next one by changing `xit` to
+`it`.
+
+## Submitting your solution
+
+You can submit your solution using the `exercism submit hello-world.ts` command.
+This command will upload your solution to the Exercism website and print the solution page's URL.
+
+It's possible to submit an incomplete solution which allows you to:
+
+- See how others have completed the exercise
+- Request help from a mentor
+
+## Need to get help?
+
+If you'd like help solving the exercise, check the following pages:
+
+- The [TypeScript track's documentation](https://exercism.org/docs/tracks/typescript)
+- [Exercism's support channel on gitter](https://gitter.im/exercism/support)
+- The [Frequently Asked Questions](https://exercism.org/docs/using/faqs)
+
+Should those resources not suffice, you could submit your (incomplete) solution to request mentoring.
+
+To get help if you're having trouble, you can use one of the following resources:
+
+- [TypeScript QuickStart](https://www.typescriptlang.org/docs/handbook/release-notes/overview.html)
+- [ECMAScript 2015 Language Specification](https://www.ecma-international.org/wp-content/uploads/ECMA-262_6th_edition_june_2015.pdf) (pdf)
+- [Mozilla JavaScript Reference](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference)
+- [/r/typescript](https://www.reddit.com/r/typescript) is the TypeScript subreddit.
+- [StackOverflow](https://stackoverflow.com/questions/tagged/typescript) can be used to search for your problem and see if it has been answered already. You can also ask and answer questions.

typescript/hello-world/README.md

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+# Hello World
+
+Welcome to Hello World on Exercism's TypeScript Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+
+## Instructions
+
+The classical introductory exercise. Just say "Hello, World!".
+
+["Hello, World!"](http://en.wikipedia.org/wiki/%22Hello,_world!%22_program) is
+the traditional first program for beginning programming in a new language
+or environment.
+
+The objectives are simple:
+
+- Write a function that returns the string "Hello, World!".
+- Run the test suite and make sure that it succeeds.
+- Submit your solution and check it at the website.
+
+If everything goes well, you will be ready to fetch your first real exercise.
+
+## Setup
+
+Go through the setup instructions for TypeScript to
+install the necessary dependencies:
+
+http://exercism.org/languages/typescript
+
+## Requirements
+
+Install assignment dependencies:
+
+```bash
+$ yarn install
+```
+
+## Making the test suite pass
+
+Execute the tests with:
+
+```bash
+$ yarn test
+```
+
+In many test suites all but the first test have been skipped.
+
+Once you get a test passing, you can unskip the next one by
+changing `xit` to `it`.
+
+## Tutorial
+
+This section is a step-by-step guide to solving this exercise.
+
+This exercise has two files:
+
+- hello-world.ts
+- hello-world.test.ts
+
+The first file is where you will write your code.
+The second is where the tests are defined.
+
+The tests will check whether your code is doing the right thing.
+You don't need to be able to write a test suite from scratch,
+but it helps to understand what a test looks like, and what
+it is doing.
+
+Open up the test file, hello-world.test.ts.
+There is a single test inside:
+
+```typescript
+it('says hello world', () => {
+  expect(hello()).toEqual('Hello, World!')
+})
+```
+
+Run the test now, with the following command on the command-line:
+
+```bash
+$ yarn test
+```
+
+The test fails, which makes sense since you've not written any code yet.
+
+The failure looks like this:
+
+```
+    × says hello world (5ms)
+
+  ● Hello World › says hello world
+
+    expect(received).toEqual(expected) // deep equality
+
+    Expected: "Hello, World!"
+    Received: "Goodbye, Mars!"
+
+      4 |
+      5 |   it('says hello world', () => {
+    > 6 |     expect(hello()).toEqual('Hello, World!')
+        |                     ^
+      7 |   })
+      8 |
+      9 | })
+
+      at Object.it (hello-world.test.ts:6:32)
+```
+
+And these are those code lines with probable defects in the `hello-world.test.ts` file:
+
+the 6th line:
+
+```typescript
+    expect(hello()).toEqual('Hello, World!')
+                    ^
+```
+
+Hence the problem is with the `hello()` function call.
+We can see that the test is expecting `'Hello, World!'` as output, but instead is getting `"Goodbye, Mars!"`.
+
+So let's check now this function in the `hello-worlds.ts` file:
+
+```typescript
+export function hello(): string {
+  return 'Goodbye, Mars!'
+}
+```
+
+Now we see that the function returns the incorrect string, which is the reason for our failure. Let's fix this by changing the returned value:
+
+```typescript
+export function hello(): string {
+  return 'Hello, World!'
+}
+```
+
+Run the test again:
+
+```bash
+ PASS  ./hello-world.test.ts
+  Hello World
+    √ says hello world (4ms)
+```
+
+And it passes!
+
+## Source
+
+### Created by
+
+- @masters3d
+
+### Contributed to by
+
+- @DFXLuna
+- @iHiD
+- @kytrinyx
+- @lukaszklis
+- @porkostomus
+- @SleeplessByte
+
+### Based on
+
+This is an exercise to introduce users to using Exercism - http://en.wikipedia.org/wiki/%22Hello,_world!%22_program

typescript/hello-world/babel.config.cjs

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+module.exports = {
+  presets: ['@exercism/babel-preset-typescript'],
+  plugins: [],
+}

typescript/hello-world/hello-world.test.ts

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+import { hello } from './hello-world'
+
+describe('Hello World', () => {
+  it('says hello world', () => {
+    expect(hello()).toEqual('Hello, World!')
+  })
+})

typescript/hello-world/hello-world.ts

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+export function hello(): string {
+  return 'Hello, World!'
+}

typescript/hello-world/jest.config.cjs

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+module.exports = {
+  verbose: true,
+  projects: ['<rootDir>'],
+  testMatch: [
+    '**/__tests__/**/*.[jt]s?(x)',
+    '**/test/**/*.[jt]s?(x)',
+    '**/?(*.)+(spec|test).[jt]s?(x)',
+  ],
+  testPathIgnorePatterns: [
+    '/(?:production_)?node_modules/',
+    '.d.ts$',
+    '<rootDir>/test/fixtures',
+    '<rootDir>/test/helpers',
+    '__mocks__',
+  ],
+  transform: {
+    '^.+\\.[jt]sx?$': 'babel-jest',
+  },
+}

typescript/hello-world/package.json

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+{
+  "name": "@exercism/typescript-hello-world",
+  "version": "1.0.0",
+  "description": "Exercism exercises in Typescript.",
+  "private": true,
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/exercism/typescript"
+  },
+  "type": "module",
+  "engines": {
+    "node": "^14.13.1 || >=16.0.0"
+  },
+  "devDependencies": {
+    "@exercism/babel-preset-typescript": "^0.1.0",
+    "@exercism/eslint-config-typescript": "^0.4.1",
+    "@types/jest": "^27.4.0",
+    "@types/node": "^16.11.24",
+    "babel-jest": "^27.5.1",
+    "core-js": "^3.21.0",
+    "eslint": "^8.9.0",
+    "jest": "^27.5.1",
+    "typescript": "^4.5.4"
+  },
+  "scripts": {
+    "test": "yarn lint:types && jest --no-cache",
+    "lint": "yarn lint:types && yarn lint:ci",
+    "lint:types": "yarn tsc --noEmit -p .",
+    "lint:ci": "eslint . --ext .tsx,.ts"
+  }
+}

typescript/hello-world/tsconfig.json

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+{
+  "display": "Configuration for Exercism TypeScript Exercises",
+  "compilerOptions": {
+    // Allows you to use the newest syntax, and have access to console.log
+    // https://www.typescriptlang.org/tsconfig#lib
+    "lib": ["ESNEXT", "dom"],
+    // Make sure typescript is configured to output ESM
+    // https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c#how-can-i-make-my-typescript-project-output-esm
+    "module": "ES2020",
+    // Since this project is using babel, TypeScript may target something very
+    // high, and babel will make sure it runs on your local Node version.
+    // https://babeljs.io/docs/en/
+    "target": "ESNext", // ESLint doesn't support this yet: "es2022",
+
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+
+    // Because we'll be using babel: ensure that Babel can safely transpile
+    // files in the TypeScript project.
+    //
+    // https://babeljs.io/docs/en/babel-plugin-transform-typescript/#caveats
+    "isolatedModules": true
+  },
+  "include": ["*.ts", "*.tsx", ".meta/*.ts", ".meta/*.tsx"],
+  "exclude": ["node_modules"]
+}