Use eslint config from the js sdk

Extend the js sdk's eslint config to give as consistent a code
style as possible. Add react/jsx/flow stuff that we use here.

.eslintrc

@@ -1,117 +0,0 @@
-{
-  "parser": "babel-eslint",
-  "plugins": [
-    "react",
-    "flowtype"
-  ],
-  "parserOptions": {
-    "ecmaVersion": 6,
-    "sourceType": "module",
-    "ecmaFeatures": {
-      "jsx": true,
-      "impliedStrict": true
-    }
-  },
-  "env": {
-    "browser": true,
-    "amd": true,
-    "es6": true,
-    "node": true,
-    "mocha": true
-  },
-  "extends": ["eslint:recommended", "plugin:react/recommended"],
-  "rules": {
-    "no-undef": ["warn"],
-    "global-strict": ["off"],
-    "no-extra-semi": ["warn"],
-    "no-underscore-dangle": ["off"],
-    "no-console": ["off"],
-    "no-unused-vars": ["off"],
-    "no-trailing-spaces": ["warn", {
-      "skipBlankLines": true
-    }],
-    "no-unreachable": ["warn"],
-    "no-spaced-func": ["warn"],
-    "no-new-func": ["error"],
-    "no-new-wrappers": ["error"],
-    "no-invalid-regexp": ["error"],
-    "no-extra-bind": ["error"],
-    "no-magic-numbers": ["error", {
-      "ignore": [-1, 0, 1], // usually used in array/string indexing
-      "ignoreArrayIndexes": true,
-      "enforceConst": true,
-      "detectObjects": true
-    }],
-    "consistent-return": ["error"],
-    "valid-jsdoc": ["error"],
-    "no-use-before-define": ["error"],
-    "camelcase": ["warn"],
-    "array-callback-return": ["error"],
-    "dot-location": ["warn", "property"],
-    "guard-for-in": ["error"],
-    "no-useless-call": ["warn"],
-    "no-useless-escape": ["warn"],
-    "no-useless-concat": ["warn"],
-    "brace-style": ["warn", "1tbs"],
-    "comma-style": ["warn", "last"],
-    "space-before-function-paren": ["warn", "never"],
-    "space-before-blocks": ["warn", "always"],
-    "keyword-spacing": ["warn", {
-      "before": true,
-      "after": true
-    }],
-
-    // dangling commas required, but only for multiline objects/arrays
-    "comma-dangle": ["warn", "always-multiline"],
-    // always === instead of ==, unless dealing with null/undefined
-    "eqeqeq": ["error", "smart"],
-    // always use curly braces, even with single statements
-    "curly": ["error", "all"],
-    // phasing out var in favour of let/const is a good idea
-    "no-var": ["warn"],
-    // always require semicolons
-    "semi": ["error", "always"],
-    // prefer rest and spread over the Old Ways
-    "prefer-spread": ["warn"],
-    "prefer-rest-params": ["warn"],
-
-    /** react **/
-
-    // bind or arrow function in props causes performance issues
-    "react/jsx-no-bind": ["error", {
-      "ignoreRefs": true
-    }],
-    "react/jsx-key": ["error"],
-    "react/prefer-stateless-function": ["warn"],
-
-    /** flowtype **/
-    "flowtype/require-parameter-type": [
-      1,
-      {
-        "excludeArrowFunctions": true
-      }
-    ],
-    "flowtype/define-flow-type": 1,
-    "flowtype/require-return-type": [
-      1,
-      "always",
-      {
-        "annotateUndefined": "never",
-        "excludeArrowFunctions": true
-      }
-    ],
-    "flowtype/space-after-type-colon": [
-      1,
-      "always"
-    ],
-    "flowtype/space-before-type-colon": [
-      1,
-      "never"
-    ]
-  },
-  "settings": {
-    "flowtype": {
-      "onlyFilesWithFlowAnnotation": true
-    }
-  }
-}

.eslintrc.js

@@ -0,0 +1,62 @@
+module.exports = {
+    parser: "babel-eslint",
+    extends: ["./node_modules/matrix-js-sdk/.eslintrc.js"],
+    plugins: [
+      "react",
+      "flowtype",
+    ],
+    env: {
+        es6: true,
+    },
+    parserOptions: {
+        ecmaFeatures: {
+            jsx: true,
+        }
+    },
+    rules: {
+        /** react **/
+        // This just uses the react plugin to help eslint known when
+        // variables have been used in JSX
+        "react/jsx-uses-vars": "error",
+
+        // bind or arrow function in props causes performance issues
+        "react/jsx-no-bind": ["error", {
+            "ignoreRefs": true,
+        }],
+        "react/jsx-key": ["error"],
+
+        /** flowtype **/
+        "flowtype/require-parameter-type": ["warn", {
+            "excludeArrowFunctions": true,
+        }],
+        "flowtype/define-flow-type": "warn",
+        "flowtype/require-return-type": ["warn",
+            "always",
+            {
+              "annotateUndefined": "never",
+              "excludeArrowFunctions": true,
+            }
+        ],
+        "flowtype/space-after-type-colon": ["warn", "always"],
+        "flowtype/space-before-type-colon": ["warn", "never"],
+
+        /*
+         * things that are errors in the js-sdk config that the current
+         * code does not adhere to, turned down to warn
+         */
+        "max-len": ["warn"],
+        "valid-jsdoc": ["warn"],
+        "new-cap": ["warn"],
+        "key-spacing": ["warn"],
+        "arrow-parens": ["warn"],
+        "prefer-const": ["warn"],
+
+        // crashes currently: https://github.com/eslint/eslint/issues/6274
+        "generator-star-spacing": "off",
+    },
+    settings: {
+        flowtype: {
+            onlyFilesWithFlowAnnotation: true
+        },
+    },
+};

package.json

@@ -74,7 +74,7 @@
   "devDependencies": {
     "babel-cli": "^6.5.2",
     "babel-core": "^6.14.0",
-    "babel-eslint": "^6.1.0",
+    "babel-eslint": "^6.1.2",
     "babel-loader": "^6.2.5",
     "babel-plugin-add-module-exports": "^0.2.1",
     "babel-plugin-transform-async-to-generator": "^6.16.0",
@@ -86,9 +86,10 @@
     "babel-preset-es2016": "^6.11.3",
     "babel-preset-es2017": "^6.14.0",
     "babel-preset-react": "^6.11.1",
-    "eslint": "^2.13.1",
-    "eslint-plugin-flowtype": "^2.17.0",
-    "eslint-plugin-react": "^6.2.1",
+    "eslint": "^3.13.1",
+    "eslint-config-google": "^0.7.1",
+    "eslint-plugin-flowtype": "^2.30.0",
+    "eslint-plugin-react": "^6.9.0",
     "expect": "^1.16.0",
     "json-loader": "^0.5.3",
     "karma": "^0.13.22",