Fix Flow usage

The initial stages of Flow in here were woefully incomplete. This brings
things to a state where flow is at least checking a majority of the main
file and has basic definitions of the used modules.

.flowconfig

@@ -4,7 +4,7 @@
 [include]
 
 [libs]
+decls
 
 [options]
-module.system=node
 suppress_comment= \\(.\\|\n\\)*\\$FlowIgnore

.travis.yml

@@ -1,19 +1,22 @@
 ### Project specific config ###
-language: generic
+language: node_js
 
 matrix:
   include:
     - os: linux
       env: ATOM_CHANNEL=stable
+      node_js: "node"
 
     - os: linux
       env: ATOM_CHANNEL=beta
+      node_js: "node"
 
 ### Generic setup follows ###
 script:
   - curl -s -O https://raw.githubusercontent.com/atom/ci/master/build-package.sh
   - chmod u+x build-package.sh
   - ./build-package.sh
+  - npm run lint
 
 notifications:
   email:

circle.yml

@@ -1,10 +1,13 @@
-test:
+dependencies:
   override:
     - curl -s -O https://raw.githubusercontent.com/atom/ci/master/build-package.sh
     - chmod u+x build-package.sh
-    - ./build-package.sh
 
-dependencies:
+test:
   override:
-    # If nothing is put here, CircleCI will run `npm install` using the system Node.js
-    - echo "Managed in the script"
+    - ./build-package.sh
+    - npm run lint
+
+machine:
+  node:
+    version: 6.3.0

decls/.eslintrc.js

@@ -0,0 +1,6 @@
+module.exports = {
+  rules: {
+    'no-unused-vars': 'off',
+    'no-undef': 'off'
+  }
+}

decls/atom-linter.js

@@ -0,0 +1,29 @@
+// @flow
+
+/* eslint-disable import/extensions, import/no-extraneous-dependencies */
+import type { TextEditor } from 'atom';
+/* eslint-enable import/extensions, import/no-extraneous-dependencies */
+
+declare type ExecOptions = {
+  timeout?: number,
+  stream?: 'stdout' | 'stderr' | 'both',
+  env?: Object,
+  stdin?: string | Buffer,
+  local?: {
+    directory: string,
+    prepend?: boolean
+  },
+  throwOnStderr?: boolean,
+  allowEmptyStderr?: boolean,
+  ignoreExitCode?: boolean
+}
+
+declare module 'atom-linter' {
+  declare var findCachedAsync:
+    (directory: string, names: string | Array<string>) => Promise<?string>;
+  declare var execNode:
+    (filePath: string, args: Array<string>, options: ExecOptions) => Promise<string>;
+  declare var generateRange:
+    (textEditor: TextEditor, lineNumber?: number, colStart?: number) =>
+      Array<Array<number>>
+}

decls/atom-package-deps.js

@@ -0,0 +1,5 @@
+// @flow
+
+declare module 'atom-package-deps' {
+  declare var install: (name: string) => void;
+}

decls/atom.js

@@ -0,0 +1,30 @@
+// @flow
+
+declare var atom: Object;
+
+declare class Disposable {
+  dispose(): void;
+}
+
+declare module 'atom' {
+  declare class CompositeDisposable {
+    add(...observable: Array<Disposable>): void;
+  }
+
+  declare type Buffer = {
+    getLineCount: () => number,
+    lineLengthForRow: () => number,
+  }
+
+  declare type TextEditor = {
+    getPath: () => string,
+    getText: () => string,
+    getGrammar: () => {
+      scopeName: string
+    },
+    getBuffer: () => Buffer,
+    // setCursorBufferPosition: (point: Point) => void,
+    // scrollToCursorPosition: () => void,
+    // onDidStopChanging: (cb: () => void) => any
+    }
+}

decls/jshint-json.js

@@ -0,0 +1,5 @@
+// @flow
+
+declare module 'jshint-json' {
+  declare module.exports: string;
+}

lib/main.js

@@ -3,8 +3,10 @@
 /* @flow */
 
 import Path from 'path';
-// eslint-disable-next-line import/extensions, import/no-extraneous-dependencies
+/* eslint-disable import/extensions, import/no-extraneous-dependencies */
 import { CompositeDisposable } from 'atom';
+import type { TextEditor } from 'atom';
+/* eslint-enable import/extensions, import/no-extraneous-dependencies */
 
 module.exports = {
   config: {
@@ -76,7 +78,7 @@ module.exports = {
       grammarScopes: this.scopes,
       scope: 'file',
       lintOnFly: true,
-      lint: async (textEditor) => {
+      lint: async (textEditor: TextEditor) => {
         const results = [];
         const filePath = textEditor.getPath();
         const fileContents = textEditor.getText();

package.json

@@ -7,7 +7,7 @@
   "license": "MIT",
   "scripts": {
     "test": "apm test",
-    "lint": "eslint ."
+    "lint": "eslint lib spec decls && flow check"
   },
   "package-deps": [
     "linter"
@@ -19,11 +19,14 @@
     "jshint-json": "^1.0.0"
   },
   "devDependencies": {
+    "babel-eslint": "^7.2.3",
     "eslint": "^3.12.0",
     "eslint-config-airbnb-base": "^11.0.0",
-    "eslint-plugin-import": "^2.2.0"
+    "eslint-plugin-import": "^2.2.0",
+    "flow-bin": "^0.45.0"
   },
   "eslintConfig": {
+    "parser": "babel-eslint",
     "rules": {
       "global-require": "off",
       "import/no-unresolved": [