Add support for flow-runtime.

.babelrc

@@ -29,6 +29,7 @@
       "rename": "./config/babel/getComponentName.babel.js"
     }],
     "@babel/plugin-transform-runtime",
+    "babel-plugin-flow-runtime",
     ["module-resolver", {"alias": {"": "./src"}}]
   ]
 }

.flowconfig

@@ -8,3 +8,4 @@
 emoji=true
 module.name_mapper='^/\(.*\)$' -> '<PROJECT_ROOT>/src/\1'
 module.name_mapper.extension='css' -> '<PROJECT_ROOT>/flow-stub/CSSModule.js'
+suppress_comment=\\(.\\|\n\\)*\\$ExpectError

.nvmrc

@@ -1 +1 @@
-9
+9.4.0

flow-typed/type-defs.js

@@ -10,6 +10,13 @@ declare module 'react-dom' {
   ): React$ElementRef<ElementType>;
 }
 
+declare module 'flow-runtime' {
+  declare type Type<T> = {
+    assert: (input: any) => T,
+  };
+  declare var reify: any;
+}
+
 /*
 note: this also needs to be added for ramda:
 declare function chain<U, T> (

package.json

@@ -25,6 +25,7 @@
     "@babel/runtime": "^7.0.0-beta.38",
     "autoprefixer": "^7.2.5",
     "babel-loader": "^8.0.0-beta.0",
+    "babel-plugin-flow-runtime": "^0.15.0",
     "babel-plugin-module-resolver": "^3.0.0",
     "babel-plugin-react-rename": "^0.1.0",
     "clean-webpack-plugin": "^0.1.17",
@@ -33,7 +34,9 @@
     "css-loader": "^0.28.9",
     "extract-css-chunks-webpack-plugin": "^2.0.18",
     "find-nearest-file": "^1.1.0",
+    "flow-runtime": "^0.16.0",
     "htmlescape": "^1.1.1",
+    "immutable": "^3.8.2",
     "midori": "^1.0.0",
     "pages-webpack-plugin": "^0.1.0",
     "postcss-loader": "^2.0.10",

test/flow/reify.js

@@ -0,0 +1,15 @@
+/* @flow */
+
+import {reify} from 'flow-runtime';
+import type {Type} from 'flow-runtime';
+
+type User = {
+  username: string,
+  age: number,
+};
+
+const json = {foo: 5};
+const user = (reify: Type<User>).assert(json);
+
+// $ExpectError
+user.x;