Replace onelint with prettier

Author: papandreou

.editorconfig

@@ -1,13 +1,12 @@
+# This file is for unifying the coding style for different editors and IDEs
+# editorconfig.org
+
 root = true
 
 [*]
 end_of_line = lf
+charset = utf-8
 insert_final_newline = true
-indent_size = 4
+trim_trailing_whitespace = true
 indent_style = space
-
-[Makefile]
-indent_style = tab
-
-[*.json]
 indent_size = 2

.eslintrc.js

@@ -1,5 +1,15 @@
-module.exports = {
-    extends: [
-        'onelint'
-    ]
+const config = {
+  extends: ['pretty-standard']
 };
+
+if (process.stdin.isTTY) {
+  // Enable plugin-prettier when running in a terminal. Allows us to have
+  // eslint verify prettier formatting, while not being bothered by it in our
+  // editors.
+  config.plugins = config.plugins || [];
+  config.plugins.push('prettier');
+  config.rules = config.rules || {};
+  config.rules['prettier/prettier'] = 'error';
+}
+
+module.exports = config;

.prettierignore

@@ -0,0 +1 @@
+package.json

.prettierrc

@@ -0,0 +1,3 @@
+{
+  "singleQuote": true
+}

package.json

@@ -15,10 +15,12 @@
   "devDependencies": {
     "coveralls": "^3.0.0",
     "eslint": "^5.1.0",
-    "eslint-config-onelint": "^4.0.0",
+    "eslint-config-pretty-standard": "^2.0.0",
+    "eslint-plugin-prettier": "^3.0.0",
     "istanbul": "^0.4.5",
     "magicpen": "^5.12.0",
     "mocha": "^5.1.5",
+    "prettier": "^1.15.2",
     "unexpected": "^10.3.1",
     "unexpected-documentation-site-generator": "^5.0.0",
     "unexpected-markdown": "^1.3.2"