Native Flow, use Jest (#767)

* build: Use Flow syntax without comments.

We're switching to Flow annotations - not Flow comments. This
gives documentation.js the ability to self-document without
JSDoc types and improves our compatibility with tools like
prettier.

Fixes #729. Fixes #709

Author: tmcw

.babelrc

@@ -0,0 +1,6 @@
+{
+  "presets": ["flow"],
+  "plugins": [
+    "transform-es2015-modules-commonjs"
+  ]
+}

.eslintignore

@@ -1 +1,5 @@
-test/fixture/*
+__tests__/fixture/*
+src/default_theme/*
+coverage/*
+lib/*
+declarations/*

.eslintrc

@@ -2,7 +2,7 @@
   "root": true,
   "parser": "babel-eslint",
   "parserOptions": {
-    "sourceType": "script"
+    "sourceType": "module"
   },
   "plugins": [
     "flowtype"
@@ -31,6 +31,7 @@
   },
   "extends": [
     "eslint:recommended",
+    "plugin:flowtype/recommended",
     "prettier"
   ],
   "env": {

.flowconfig

@@ -1,7 +1,8 @@
 [ignore]
 .*node_modules/.cache/.*
 .*node_modules/conventional-changelog-core/test/fixtures/.*
-.*/test/fixture/.*
+.*/__tests__/fixture/.*
+./lib/.*
 
 [include]
 

.gitignore

@@ -1,3 +1,4 @@
+/lib
 coverage
 .nyc_output
-node_modules
+/node_modules

test/.eslintrc __tests__/.eslintrc

@@ -2,5 +2,8 @@
   "rules": {
     "valid-jsdoc": [0],
     "no-unused-vars": [0]
+  },
+  "env": {
+    "jest": true
   }
 }

__tests__/__snapshots__/bin-readme.js.snap

@@ -0,0 +1,59 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`readme command --readme-file 1`] = `
+"# A title
+
+# API
+
+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+## foo
+
+A function with documentation.
+
+**Parameters**
+
+-   \`a\`  {string} blah
+
+Returns **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** answer
+
+## bar
+
+A second function with docs
+
+**Parameters**
+
+-   \`b\`  
+
+# Another section
+"
+`;
+
+exports[`readme command updates README.md 1`] = `
+"# A title
+
+# API
+
+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+## foo
+
+A function with documentation.
+
+**Parameters**
+
+-   \`a\`  {string} blah
+
+Returns **[number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** answer
+
+## bar
+
+A second function with docs
+
+**Parameters**
+
+-   \`b\`  
+
+# Another section
+"
+`;