Upgrade Typescript, tslint -> eslint (#22)

* Upgrade Typescript, tslint -> eslint

* Upgrade Travis dist to focal

Author: RoryH

.eslintignore

@@ -0,0 +1,2 @@
+dist
+node_modules

.eslintrc.js

@@ -0,0 +1,51 @@
+module.exports = {
+  root: true,
+  extends: [
+    'airbnb-base',
+    'plugin:import/errors',
+    'plugin:import/warnings',
+    'plugin:import/typescript',
+  ],
+  plugins: ['@typescript-eslint'],
+  parser: '@typescript-eslint/parser',
+  rules: {
+    'import/noUnresolved': 0,
+    'import/extensions': ['error', 'always', {
+      ts: 'never',
+      js: 'never',
+    }],
+  },
+  overrides: [{
+    files: ['src/**'],
+    parser: '@typescript-eslint/parser',
+    parserOptions: {
+      project: 'tsconfig.json',
+      sourceType: 'module',
+    },
+    extends: [
+      'airbnb-base-typescript',
+    ],
+  }, {
+    // jest
+    files: [
+      'test/**/*.ts',
+      'jest.setup.js',
+    ],
+    parserOptions: {
+      project: 'tsconfig.json',
+      sourceType: 'module',
+    },
+    env: {
+      jest: true,
+    },
+    extends: [
+      'plugin:jest/recommended',
+      'plugin:jest/style',
+    ],
+    rules: {
+      // development dependencies are hoisted to the root
+      'import/no-extraneous-dependencies': 'off',
+      'no-console': 'off',
+    },
+  }],
+};

.travis.yml

@@ -1,6 +1,7 @@
 language: node_js
+dist: focal
 node_js:
-- 14
+- 18
 cache:
   directories:
   - $HOME/.npm

jest.config.js

@@ -1,14 +1,14 @@
 module.exports = {
-  "transform": {
-    "^.+\\.tsx?$": "ts-jest"
+  transform: {
+    '^.+\\.tsx?$': 'ts-jest',
   },
-  "testRegex": "(/__tests__/.*|(\\.|/)(test|spec))\\.tsx?$",
-  "moduleFileExtensions": [
-    "ts",
-    "tsx",
-    "js",
-    "jsx",
-    "json",
-    "node"
+  testRegex: '(/__tests__/.*|(\\.|/)(test|spec))\\.tsx?$',
+  moduleFileExtensions: [
+    'ts',
+    'tsx',
+    'js',
+    'jsx',
+    'json',
+    'node',
   ],
-}
+};