➕ Add babel, eslint, and istanbul

.eslintrc

@@ -0,0 +1,19 @@
+parser: babel-eslint
+extends: standard
+plugins:
+  - babel
+rules:
+  prefer-const: off
+  no-unused-expressions: off
+  babel/no-unused-expressions: warn
+  promise/param-names: off
+  semi: [error, always]
+  generator-star-spacing:
+    - error
+    - before: false
+      after: false
+  space-before-function-paren:
+    - error
+    - anonymous: never
+      asyncArrow: always
+      named: never

.nycrc

@@ -0,0 +1,8 @@
+{
+  "exclude": ["dist", "test"],
+  "check-coverage": true,
+  "branches": 100,
+  "lines": 100,
+  "functions": 100,
+  "statements": 100
+}

babel.config.js

@@ -0,0 +1,21 @@
+module.exports = {
+  presets: [
+    ['@babel/env', {
+      targets: {
+        node: '10'
+      }
+    }]
+  ],
+  plugins: [
+    '@babel/proposal-class-properties'
+  ],
+  env: {
+    test: {
+      plugins: [
+        ['istanbul', {
+          exclude: ['dist', 'test']
+        }]
+      ]
+    }
+  }
+}

package.json

@@ -1,5 +1,22 @@
 {
   "private": true,
   "workspaces": [
-  ]
+  ],
+  "devDependencies": {
+    "@babel/cli": "^7.8.3",
+    "@babel/core": "^7.8.3",
+    "@babel/plugin-proposal-class-properties": "^7.8.3",
+    "@babel/preset-env": "^7.8.3",
+    "@babel/register": "^7.8.3",
+    "babel-eslint": "^10.0.3",
+    "babel-plugin-istanbul": "^6.0.0",
+    "eslint": "^6.8.0",
+    "eslint-config-standard": "^14.1.0",
+    "eslint-plugin-babel": "^5.3.0",
+    "eslint-plugin-import": "^2.20.0",
+    "eslint-plugin-node": "^11.0.0",
+    "eslint-plugin-promise": "^4.2.1",
+    "eslint-plugin-standard": "^4.0.1",
+    "nyc": "^15.0.0"
+  }
 }

scripts/babel-register.js

@@ -0,0 +1,15 @@
+const path = require('path')
+
+require('@babel/register')({
+  // allow monorepos to share a single babel config
+  rootMode: 'upward',
+
+  // specified without the cwd so tests can share helpers
+  only: [
+    new RegExp(
+      ['packages', '.*?', '(src|test)']
+      // escape windows path seperators and escape the escape
+        .join(path.sep === '/' ? '/' : '\\\\')
+    )
+  ]
+})