tutorial boilerplate test

.babelrc

@@ -0,0 +1,6 @@
+{
+  "presets": [
+    ["@babel/preset-env", { "targets": { "node": "10" } }],
+    "@babel/preset-typescript"
+  ]
+}

.eslintrc.json

@@ -0,0 +1,29 @@
+{
+  "env": {
+    "browser": true,
+    "es2021": true
+  },
+  "extends": [
+    "eslint:recommended",
+    "plugin:@typescript-eslint/recommended",
+    "plugin:@typescript-eslint/recommended-requiring-type-checking"
+  ],
+  "parser": "@typescript-eslint/parser",
+  "parserOptions": {
+    "ecmaVersion": 12,
+    "project": "tsconfig.eslint.json"
+  },
+  "plugins": ["@typescript-eslint"],
+  "rules": {
+    "prefer-const": "error",
+    "@typescript-eslint/no-unused-var": "off",
+    "@typescript-eslint/no-unused-params": "off"
+  },
+  "root": true,
+  "overrides": [
+    {
+      "files": ["tests/**/*.ts"],
+      "env": { "jest": true, "node": true }
+    }
+  ]
+}

package.json

@@ -11,12 +11,19 @@
     "test": "jest"
   },
   "devDependencies": {
+    "@babel/preset-env": "^7.13.12",
+    "@types/jest": "^26.0.21",
+    "@typescript-eslint/eslint-plugin": "^4.19.0",
+    "@typescript-eslint/parser": "^4.19.0",
     "eslint": "^7.22.0",
     "jest": "^26.6.3",
     "typescript": "^4.2.3"
   },
   "volta": {
     "node": "14.16.0",
     "yarn": "1.22.10"
+  },
+  "dependencies": {
+    "@babel/preset-typescript": "^7.13.0"
   }
 }

src/index.ts

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+/**
+ * @packageDocumentation A small library for common math functions
+ */
+
+/**
+ * Calculate the average of three numbers
+ *
+ * @param a - first number
+ * @param b - second number
+ * @param c - third number
+ *
+ * @public
+ */
+export function avg(a: number, b: number, c: number): number {
+  return sum3(a, b, c) / 3;
+}
+
+/**
+ * Calculate the sum of three numbers
+ *
+ * @param a - first number
+ * @param b - second number
+ * @param c - third number
+ *
+ * @beta
+ */
+export function sum3(a: number, b: number, c: number): number {
+  return sum2(a, sum2(b, c));
+}
+
+/**
+ * Calculate the sum of two numbers
+ *
+ * @param a - first number
+ * @param b - second number
+ *
+ * @internal
+ */
+export function sum2(a: number, b: number): number {
+  const sum = a + b;
+  return sum;
+}

tests/index.test.ts

@@ -0,0 +1,19 @@
+import { avg, sum3 } from '..';
+
+describe('avg should calculate an average properly', () => {
+  test('three positive numbers', () => {
+    expect(avg(3, 4, 5)).toBe(4);
+  });
+  test('three negative numbers', () => {
+    expect(avg(3, -4, -5)).toBe(-2);
+  });
+});
+
+describe('sum3 should calculate a sum properly', () => {
+  test('three positive numbers', () => {
+    expect(sum3(3, 4, 5)).toBe(12);
+  });
+  test('three negative numbers', () => {
+    expect(sum3(3, -4, -5)).toBe(-6);
+  });
+});

tests/tsconfig.json

@@ -0,0 +1,10 @@
+{
+  "extends": "../tsconfig.json",
+  "references": [{ "name": "my-lib", "path": ".." }],
+  "compilerOptions": {
+    "types": ["jest"],
+    "rootDir": "..",
+    "noEmit": true
+  },
+  "include": ["."]
+}

tsconfig.eslint.json

@@ -0,0 +1,7 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "types": ["jest"]
+  },
+  "include": ["src", "tests"]
+}

tsconfig.json

@@ -0,0 +1,73 @@
+{
+  "compilerOptions": {
+    /* Visit https://aka.ms/tsconfig.json to read more about this file */
+
+    /* Basic Options */
+    // "incremental": true,                         /* Enable incremental compilation */
+    "target": "ESNEXT" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. */,
+    "module": "commonjs" /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */,
+    // "lib": [],                                   /* Specify library files to be included in the compilation. */
+    // "allowJs": true,                             /* Allow javascript files to be compiled. */
+    // "checkJs": true,                             /* Report errors in .js files. */
+    // "jsx": "preserve",                           /* Specify JSX code generation: 'preserve', 'react-native', 'react', 'react-jsx' or 'react-jsxdev'. */
+    "declaration": true /* Generates corresponding '.d.ts' file. */,
+    // "declarationMap": true,                      /* Generates a sourcemap for each corresponding '.d.ts' file. */
+    // "sourceMap": true,                           /* Generates corresponding '.map' file. */
+    // "outFile": "./",                             /* Concatenate and emit output to single file. */
+    "outDir": "dist" /* Redirect output structure to the directory. */,
+    "rootDir": "src" /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */,
+    "composite": true /* Enable project compilation */,
+    // "tsBuildInfoFile": "./",                     /* Specify file to store incremental compilation information */
+    // "removeComments": true,                      /* Do not emit comments to output. */
+    // "noEmit": true,                              /* Do not emit outputs. */
+    // "importHelpers": true,                       /* Import emit helpers from 'tslib'. */
+    // "downlevelIteration": true,                  /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
+    // "isolatedModules": true,                     /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
+
+    /* Strict Type-Checking Options */
+    "strict": true /* Enable all strict type-checking options. */,
+    // "noImplicitAny": true,                       /* Raise error on expressions and declarations with an implied 'any' type. */
+    // "strictNullChecks": true,                    /* Enable strict null checks. */
+    // "strictFunctionTypes": true,                 /* Enable strict checking of function types. */
+    // "strictBindCallApply": true,                 /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
+    // "strictPropertyInitialization": true,        /* Enable strict checking of property initialization in classes. */
+    // "noImplicitThis": true,                      /* Raise error on 'this' expressions with an implied 'any' type. */
+    // "alwaysStrict": true,                        /* Parse in strict mode and emit "use strict" for each source file. */
+
+    /* Additional Checks */
+    "noUnusedLocals": true /* Report errors on unused locals. */,
+    "noUnusedParameters": true /* Report errors on unused parameters. */,
+    "noImplicitReturns": true /* Report error when not all code paths in function return a value. */,
+    "stripInternal": true,
+    // "noFallthroughCasesInSwitch": true,          /* Report errors for fallthrough cases in switch statement. */
+    // "noUncheckedIndexedAccess": true,            /* Include 'undefined' in index signature results */
+    // "noPropertyAccessFromIndexSignature": true,  /* Require undeclared properties from index signatures to use element accesses. */
+
+    /* Module Resolution Options */
+    // "moduleResolution": "node",                  /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
+    // "baseUrl": "./",                             /* Base directory to resolve non-absolute module names. */
+    // "paths": {},                                 /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
+    // "rootDirs": [],                              /* List of root folders whose combined content represents the structure of the project at runtime. */
+    // "typeRoots": [],                             /* List of folders to include type definitions from. */
+    "types": [] /* Type declaration files to be included in compilation. */,
+    // "allowSyntheticDefaultImports": true,        /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
+    "esModuleInterop": false /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */,
+    // "preserveSymlinks": true,                    /* Do not resolve the real path of symlinks. */
+    // "allowUmdGlobalAccess": true,                /* Allow accessing UMD globals from modules. */
+
+    /* Source Map Options */
+    // "sourceRoot": "",                            /* Specify the location where debugger should locate TypeScript files instead of source locations. */
+    // "mapRoot": "",                               /* Specify the location where debugger should locate map files instead of generated locations. */
+    // "inlineSourceMap": true,                     /* Emit a single file with source maps instead of having a separate file. */
+    // "inlineSources": true,                       /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */
+
+    /* Experimental Options */
+    // "experimentalDecorators": true,              /* Enables experimental support for ES7 decorators. */
+    // "emitDecoratorMetadata": true,               /* Enables experimental support for emitting type metadata for decorators. */
+
+    /* Advanced Options */
+    "skipLibCheck": false /* Skip type checking of declaration files. */,
+    "forceConsistentCasingInFileNames": true /* Disallow inconsistently-cased references to the same file. */
+  },
+  "include": ["src"]
+}