From 57da9bdbed413967f04b53212c58f2c5a76a5b58 Mon Sep 17 00:00:00 2001
From: Brian Ng <bng412@gmail.com>
Date: Thu, 20 Jul 2017 23:32:20 -0500
Subject: [PATCH 1/3] Add requireDirective to strip-flow-types for use in React
 preset

---
 .../README.md                                 |  9 +++++++
 .../src/index.js                              | 21 +++++++++++++--
 .../fixtures/requireDirective/options.json    |  3 +++
 .../true-ignores-without-directive/actual.js  |  1 +
 .../expected.js                               |  1 +
 .../true-strips-with-directive/actual.js      |  3 +++
 .../true-strips-with-directive/expected.js    |  1 +
 packages/babel-preset-react/README.md         | 27 ++++++++++++++++---
 packages/babel-preset-react/package.json      |  7 ++++-
 packages/babel-preset-react/src/index.js      | 23 +++++++++++++---
 .../test/fixtures/flow/options.json           |  5 ++++
 .../flow/strip-with-directive/actual.js       |  2 ++
 .../flow/strip-with-directive/expected.js     |  1 +
 .../flow/strip-without-directive/actual.js    |  1 +
 .../flow/strip-without-directive/expected.js  |  1 +
 .../preset-options/development/exec.js        | 19 +++++++++++++
 .../preset-options/development/options.json   |  5 ++++
 .../preset-options/empty-options/actual.js    |  1 +
 .../preset-options/empty-options/expected.js  |  3 +++
 .../preset-options/empty-options/options.json |  5 ++++
 .../preset-options/no-options/actual.js       |  1 +
 .../preset-options/no-options/expected.js     |  3 +++
 .../preset-options/no-options/options.json    |  5 ++++
 packages/babel-preset-react/test/index.js     | 20 ++++++++++++++
 .../babel-preset-react/test/preset-options.js |  3 +++
 25 files changed, 161 insertions(+), 10 deletions(-)
 create mode 100644 packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/options.json
 create mode 100644 packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-ignores-without-directive/actual.js
 create mode 100644 packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-ignores-without-directive/expected.js
 create mode 100644 packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-strips-with-directive/actual.js
 create mode 100644 packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-strips-with-directive/expected.js
 create mode 100644 packages/babel-preset-react/test/fixtures/flow/options.json
 create mode 100644 packages/babel-preset-react/test/fixtures/flow/strip-with-directive/actual.js
 create mode 100644 packages/babel-preset-react/test/fixtures/flow/strip-with-directive/expected.js
 create mode 100644 packages/babel-preset-react/test/fixtures/flow/strip-without-directive/actual.js
 create mode 100644 packages/babel-preset-react/test/fixtures/flow/strip-without-directive/expected.js
 create mode 100644 packages/babel-preset-react/test/fixtures/preset-options/development/exec.js
 create mode 100644 packages/babel-preset-react/test/fixtures/preset-options/development/options.json
 create mode 100644 packages/babel-preset-react/test/fixtures/preset-options/empty-options/actual.js
 create mode 100644 packages/babel-preset-react/test/fixtures/preset-options/empty-options/expected.js
 create mode 100644 packages/babel-preset-react/test/fixtures/preset-options/empty-options/options.json
 create mode 100644 packages/babel-preset-react/test/fixtures/preset-options/no-options/actual.js
 create mode 100644 packages/babel-preset-react/test/fixtures/preset-options/no-options/expected.js
 create mode 100644 packages/babel-preset-react/test/fixtures/preset-options/no-options/options.json
 create mode 100644 packages/babel-preset-react/test/index.js
 create mode 100644 packages/babel-preset-react/test/preset-options.js

diff --git a/packages/babel-plugin-transform-flow-strip-types/README.md b/packages/babel-plugin-transform-flow-strip-types/README.md
index 6e279dbfae..dfb4c0f03a 100644
--- a/packages/babel-plugin-transform-flow-strip-types/README.md
+++ b/packages/babel-plugin-transform-flow-strip-types/README.md
@@ -47,3 +47,12 @@ require("babel-core").transform("code", {
   plugins: ["transform-flow-strip-types"]
 });
 ```
+
+## Options
+
+### `requireDirective`
+
+`boolean`, defaults to `false`.
+
+Setting this to true will only strip annotations and declarations from files
+that contain the `// @flow` directive.
diff --git a/packages/babel-plugin-transform-flow-strip-types/src/index.js b/packages/babel-plugin-transform-flow-strip-types/src/index.js
index aafdb20590..c0acf431b4 100644
--- a/packages/babel-plugin-transform-flow-strip-types/src/index.js
+++ b/packages/babel-plugin-transform-flow-strip-types/src/index.js
@@ -3,13 +3,20 @@ import syntaxFlow from "babel-plugin-syntax-flow";
 export default function({ types: t }) {
   const FLOW_DIRECTIVE = "@flow";
 
+  let skipStrip = false;
+
   return {
     inherits: syntaxFlow,
 
     visitor: {
-      Program(path, { file: { ast: { comments } } }) {
+      Program(path, { file: { ast: { comments } }, opts }) {
+        skipStrip = false;
+        let directiveFound = false;
+
         for (const comment of (comments: Array<Object>)) {
           if (comment.value.indexOf(FLOW_DIRECTIVE) >= 0) {
+            directiveFound = true;
+
             // remove flow directive
             comment.value = comment.value.replace(FLOW_DIRECTIVE, "");
 
@@ -17,9 +24,13 @@ export default function({ types: t }) {
             if (!comment.value.replace(/\*/g, "").trim()) comment.ignore = true;
           }
         }
-      },
 
+        if (!directiveFound && opts.requireDirective) {
+          skipStrip = true;
+        }
+      },
       ImportDeclaration(path) {
+        if (skipStrip) return;
         if (!path.node.specifiers.length) return;
 
         let typeCount = 0;
@@ -36,16 +47,19 @@ export default function({ types: t }) {
       },
 
       Flow(path) {
+        if (skipStrip) return;
         path.remove();
       },
 
       ClassProperty(path) {
+        if (skipStrip) return;
         path.node.variance = null;
         path.node.typeAnnotation = null;
         if (!path.node.value) path.remove();
       },
 
       Class(path) {
+        if (skipStrip) return;
         path.node.implements = null;
 
         // We do this here instead of in a `ClassProperty` visitor because the class transform
@@ -59,10 +73,12 @@ export default function({ types: t }) {
       },
 
       AssignmentPattern({ node }) {
+        if (skipStrip) return;
         node.left.optional = false;
       },
 
       Function({ node }) {
+        if (skipStrip) return;
         for (let i = 0; i < node.params.length; i++) {
           const param = node.params[i];
           param.optional = false;
@@ -75,6 +91,7 @@ export default function({ types: t }) {
       },
 
       TypeCastExpression(path) {
+        if (skipStrip) return;
         let { node } = path;
         do {
           node = node.expression;
diff --git a/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/options.json b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/options.json
new file mode 100644
index 0000000000..b44aa63984
--- /dev/null
+++ b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": [["transform-flow-strip-types", { "requireDirective": true }]]
+}
diff --git a/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-ignores-without-directive/actual.js b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-ignores-without-directive/actual.js
new file mode 100644
index 0000000000..6bd1f1803c
--- /dev/null
+++ b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-ignores-without-directive/actual.js
@@ -0,0 +1 @@
+function foo(numVal: number, strVal: string) {}
diff --git a/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-ignores-without-directive/expected.js b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-ignores-without-directive/expected.js
new file mode 100644
index 0000000000..6bd1f1803c
--- /dev/null
+++ b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-ignores-without-directive/expected.js
@@ -0,0 +1 @@
+function foo(numVal: number, strVal: string) {}
diff --git a/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-strips-with-directive/actual.js b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-strips-with-directive/actual.js
new file mode 100644
index 0000000000..58edb63680
--- /dev/null
+++ b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-strips-with-directive/actual.js
@@ -0,0 +1,3 @@
+// @flow
+
+function foo(numVal: number, strVal: string) {}
diff --git a/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-strips-with-directive/expected.js b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-strips-with-directive/expected.js
new file mode 100644
index 0000000000..a828af11ee
--- /dev/null
+++ b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-strips-with-directive/expected.js
@@ -0,0 +1 @@
+function foo(numVal, strVal) {}
\ No newline at end of file
diff --git a/packages/babel-preset-react/README.md b/packages/babel-preset-react/README.md
index 591a59547b..93ce543067 100644
--- a/packages/babel-preset-react/README.md
+++ b/packages/babel-preset-react/README.md
@@ -2,13 +2,26 @@
 
 > Babel preset for all React plugins.
 
-This preset includes the following plugins/presets:
+This preset always includes the following plugins:
 
-- [preset-flow](https://babeljs.io/docs/plugins/preset-flow/)
 - [syntax-jsx](https://babeljs.io/docs/plugins/syntax-jsx/)
+- [transform-flow-strip-types](https://babeljs.io/docs/plugins/transform-flow-strip-types/)
 - [transform-react-jsx](https://babeljs.io/docs/plugins/transform-react-jsx/)
 - [transform-react-display-name](https://babeljs.io/docs/plugins/transform-react-display-name/)
 
+And with the `development` option:
+
+- [transform-react-jsx-self](https://babeljs.io/docs/plugins/transform-react-jsx-self/)
+- [transform-react-jsx-source](https://babeljs.io/docs/plugins/transform-react-jsx-source/)
+
+Note: Flow annotations and declarations will _only_ be removed in files that
+have the `// @flow ` directive.
+
+```js
+// @flow
+function foo(numVal: number, strVal: string) {}
+```
+
 ## Install
 
 > You can also check out the React [Getting Started page](https://facebook.github.io/react/docs/hello-world.html)
@@ -54,7 +67,7 @@ View the output
 ### Via CLI
 
 ```sh
-babel script.js --presets react 
+babel script.js --presets react
 ```
 
 ### Via Node API
@@ -64,3 +77,11 @@ require("babel-core").transform("code", {
   presets: ["react"]
 });
 ```
+
+## Options
+
+### `development`
+
+`boolean`, defaults to `false`.
+
+Toggles plugins that aid in development, such as [`babel-plugin-transform-react-jsx-self`](https://babeljs.io/docs/plugins/transform-react-jsx-self/) and [`babel-plugin-transform-react-jsx-source`](https://babeljs.io/docs/plugins/transform-react-jsx-source/).
diff --git a/packages/babel-preset-react/package.json b/packages/babel-preset-react/package.json
index 6616bccae6..fb48ed3c27 100644
--- a/packages/babel-preset-react/package.json
+++ b/packages/babel-preset-react/package.json
@@ -9,10 +9,15 @@
   "main": "lib/index.js",
   "dependencies": {
     "babel-plugin-syntax-jsx": "7.0.0-alpha.18",
+    "babel-plugin-transform-flow-strip-types": "7.0.0-alpha.18",
     "babel-plugin-transform-react-display-name": "7.0.0-alpha.18",
     "babel-plugin-transform-react-jsx": "7.0.0-alpha.18",
     "babel-plugin-transform-react-jsx-self": "7.0.0-alpha.18",
     "babel-plugin-transform-react-jsx-source": "7.0.0-alpha.18",
-    "babel-preset-flow": "7.0.0-alpha.18"
+    "babel-plugin-transform-react-jsx-source": "7.0.0-alpha.18"
+  },
+  "devDependencies": {
+    "babel-helper-plugin-test-runner": "7.0.0-alpha.18",
+    "babel-helper-transform-fixture-test-runner": "7.0.0-alpha.18"
   }
 }
diff --git a/packages/babel-preset-react/src/index.js b/packages/babel-preset-react/src/index.js
index f1d1c1cc6a..e2d308f4dd 100644
--- a/packages/babel-preset-react/src/index.js
+++ b/packages/babel-preset-react/src/index.js
@@ -1,11 +1,26 @@
-import presetFlow from "babel-preset-flow";
+import transformFlowStripTypes from "babel-plugin-transform-flow-strip-types";
 import transformReactJSX from "babel-plugin-transform-react-jsx";
 import transformSyntaxJSX from "babel-plugin-syntax-jsx";
 import transformReactDisplayName from "babel-plugin-transform-react-display-name";
+import transformReactJSXSource from "babel-plugin-transform-react-jsx-source";
+import transformReactJSXSelf from "babel-plugin-transform-react-jsx-self";
+
+export default function(context, opts = {}) {
+  const development = opts.development || false;
+
+  if (typeof development !== "boolean") {
+    throw new Error("Preset react 'development' option must be a boolean.");
+  }
 
-export default function() {
   return {
-    presets: [presetFlow],
-    plugins: [transformReactJSX, transformSyntaxJSX, transformReactDisplayName],
+    plugins: [
+      transformReactJSX,
+      transformSyntaxJSX,
+      transformReactDisplayName,
+
+      development && transformReactJSXSource,
+      development && transformReactJSXSelf,
+      [transformFlowStripTypes, { requireDirective: true }],
+    ].filter(Boolean),
   };
 }
diff --git a/packages/babel-preset-react/test/fixtures/flow/options.json b/packages/babel-preset-react/test/fixtures/flow/options.json
new file mode 100644
index 0000000000..2e9146fee1
--- /dev/null
+++ b/packages/babel-preset-react/test/fixtures/flow/options.json
@@ -0,0 +1,5 @@
+{
+  "presets": [
+    "react"
+  ]
+}
diff --git a/packages/babel-preset-react/test/fixtures/flow/strip-with-directive/actual.js b/packages/babel-preset-react/test/fixtures/flow/strip-with-directive/actual.js
new file mode 100644
index 0000000000..1b44b40442
--- /dev/null
+++ b/packages/babel-preset-react/test/fixtures/flow/strip-with-directive/actual.js
@@ -0,0 +1,2 @@
+// @flow
+function foo(numVal: number, strVal: string) {}
diff --git a/packages/babel-preset-react/test/fixtures/flow/strip-with-directive/expected.js b/packages/babel-preset-react/test/fixtures/flow/strip-with-directive/expected.js
new file mode 100644
index 0000000000..a828af11ee
--- /dev/null
+++ b/packages/babel-preset-react/test/fixtures/flow/strip-with-directive/expected.js
@@ -0,0 +1 @@
+function foo(numVal, strVal) {}
\ No newline at end of file
diff --git a/packages/babel-preset-react/test/fixtures/flow/strip-without-directive/actual.js b/packages/babel-preset-react/test/fixtures/flow/strip-without-directive/actual.js
new file mode 100644
index 0000000000..6bd1f1803c
--- /dev/null
+++ b/packages/babel-preset-react/test/fixtures/flow/strip-without-directive/actual.js
@@ -0,0 +1 @@
+function foo(numVal: number, strVal: string) {}
diff --git a/packages/babel-preset-react/test/fixtures/flow/strip-without-directive/expected.js b/packages/babel-preset-react/test/fixtures/flow/strip-without-directive/expected.js
new file mode 100644
index 0000000000..6bd1f1803c
--- /dev/null
+++ b/packages/babel-preset-react/test/fixtures/flow/strip-without-directive/expected.js
@@ -0,0 +1 @@
+function foo(numVal: number, strVal: string) {}
diff --git a/packages/babel-preset-react/test/fixtures/preset-options/development/exec.js b/packages/babel-preset-react/test/fixtures/preset-options/development/exec.js
new file mode 100644
index 0000000000..4fc1a143a9
--- /dev/null
+++ b/packages/babel-preset-react/test/fixtures/preset-options/development/exec.js
@@ -0,0 +1,19 @@
+const actual = transform(
+  '<Foo bar="baz" />',
+  Object.assign({}, opts, { filename: '/fake/path/mock.js' })
+).code;
+
+const expected = multiline([
+  'var _jsxFileName = "/fake/path/mock.js";',
+  'React.createElement(Foo, {',
+  '  bar: "baz",',
+  '  __source: {',
+  '    fileName: _jsxFileName,',
+  '    lineNumber: 1',
+  '  },',
+  '  __self: this',
+  '});',
+]);
+
+
+assert.equal(actual, expected);
diff --git a/packages/babel-preset-react/test/fixtures/preset-options/development/options.json b/packages/babel-preset-react/test/fixtures/preset-options/development/options.json
new file mode 100644
index 0000000000..5ce6ee2080
--- /dev/null
+++ b/packages/babel-preset-react/test/fixtures/preset-options/development/options.json
@@ -0,0 +1,5 @@
+{
+  "presets": [
+    ["react", { "development": true }]
+  ]
+}
diff --git a/packages/babel-preset-react/test/fixtures/preset-options/empty-options/actual.js b/packages/babel-preset-react/test/fixtures/preset-options/empty-options/actual.js
new file mode 100644
index 0000000000..378e2ae67b
--- /dev/null
+++ b/packages/babel-preset-react/test/fixtures/preset-options/empty-options/actual.js
@@ -0,0 +1 @@
+<Foo bar="baz" />
diff --git a/packages/babel-preset-react/test/fixtures/preset-options/empty-options/expected.js b/packages/babel-preset-react/test/fixtures/preset-options/empty-options/expected.js
new file mode 100644
index 0000000000..835263a79b
--- /dev/null
+++ b/packages/babel-preset-react/test/fixtures/preset-options/empty-options/expected.js
@@ -0,0 +1,3 @@
+React.createElement(Foo, {
+  bar: "baz"
+});
diff --git a/packages/babel-preset-react/test/fixtures/preset-options/empty-options/options.json b/packages/babel-preset-react/test/fixtures/preset-options/empty-options/options.json
new file mode 100644
index 0000000000..2f5fa2457b
--- /dev/null
+++ b/packages/babel-preset-react/test/fixtures/preset-options/empty-options/options.json
@@ -0,0 +1,5 @@
+{
+  "presets": [
+    ["react", {}]
+  ]
+}
diff --git a/packages/babel-preset-react/test/fixtures/preset-options/no-options/actual.js b/packages/babel-preset-react/test/fixtures/preset-options/no-options/actual.js
new file mode 100644
index 0000000000..378e2ae67b
--- /dev/null
+++ b/packages/babel-preset-react/test/fixtures/preset-options/no-options/actual.js
@@ -0,0 +1 @@
+<Foo bar="baz" />
diff --git a/packages/babel-preset-react/test/fixtures/preset-options/no-options/expected.js b/packages/babel-preset-react/test/fixtures/preset-options/no-options/expected.js
new file mode 100644
index 0000000000..835263a79b
--- /dev/null
+++ b/packages/babel-preset-react/test/fixtures/preset-options/no-options/expected.js
@@ -0,0 +1,3 @@
+React.createElement(Foo, {
+  bar: "baz"
+});
diff --git a/packages/babel-preset-react/test/fixtures/preset-options/no-options/options.json b/packages/babel-preset-react/test/fixtures/preset-options/no-options/options.json
new file mode 100644
index 0000000000..2e9146fee1
--- /dev/null
+++ b/packages/babel-preset-react/test/fixtures/preset-options/no-options/options.json
@@ -0,0 +1,5 @@
+{
+  "presets": [
+    "react"
+  ]
+}
diff --git a/packages/babel-preset-react/test/index.js b/packages/babel-preset-react/test/index.js
new file mode 100644
index 0000000000..eaa4969a9b
--- /dev/null
+++ b/packages/babel-preset-react/test/index.js
@@ -0,0 +1,20 @@
+import react from "../lib";
+import { expect } from "chai";
+
+describe("react preset", () => {
+  it("doesn't throw with no options passed", () => {
+    expect(() => {
+      react(null);
+    }).not.to.throw();
+  });
+
+  describe("options", () => {
+    describe("development", () => {
+      it("throws on non-boolean value", () => {
+        expect(function() {
+          react(null, { development: 1 });
+        }).to.throw(/must be a boolean/);
+      });
+    });
+  });
+});
diff --git a/packages/babel-preset-react/test/preset-options.js b/packages/babel-preset-react/test/preset-options.js
new file mode 100644
index 0000000000..09cfbc31f5
--- /dev/null
+++ b/packages/babel-preset-react/test/preset-options.js
@@ -0,0 +1,3 @@
+import runner from "babel-helper-plugin-test-runner";
+
+runner(__dirname);

From af5f34ace5cab2102a18261875eec9df838f130a Mon Sep 17 00:00:00 2001
From: Brian Ng <bng412@gmail.com>
Date: Thu, 3 Aug 2017 21:54:36 -0500
Subject: [PATCH 2/3] Throw if annotation found without directive

---
 .../babel-plugin-transform-flow-strip-types/README.md     | 3 ++-
 .../babel-plugin-transform-flow-strip-types/src/index.js  | 8 +++++++-
 .../true-does-not-throw-with-directive/actual.js          | 1 +
 .../true-does-not-throw-with-directive/expected.js        | 1 +
 .../actual.js                                             | 0
 .../true-throws-if-found-with-directive/options.json      | 3 +++
 packages/babel-preset-react/README.md                     | 6 ++++--
 .../fixtures/flow/strip-without-directive/expected.js     | 1 -
 .../actual.js                                             | 0
 .../fixtures/flow/throws-without-directive}/expected.js   | 0
 .../fixtures/flow/throws-without-directive/options.json   | 3 +++
 11 files changed, 21 insertions(+), 5 deletions(-)
 create mode 100644 packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-does-not-throw-with-directive/actual.js
 create mode 100644 packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-does-not-throw-with-directive/expected.js
 rename packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/{true-ignores-without-directive => true-throws-if-found-with-directive}/actual.js (100%)
 create mode 100644 packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-throws-if-found-with-directive/options.json
 delete mode 100644 packages/babel-preset-react/test/fixtures/flow/strip-without-directive/expected.js
 rename packages/babel-preset-react/test/fixtures/flow/{strip-without-directive => throws-without-directive}/actual.js (100%)
 rename packages/{babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-ignores-without-directive => babel-preset-react/test/fixtures/flow/throws-without-directive}/expected.js (100%)
 create mode 100644 packages/babel-preset-react/test/fixtures/flow/throws-without-directive/options.json

diff --git a/packages/babel-plugin-transform-flow-strip-types/README.md b/packages/babel-plugin-transform-flow-strip-types/README.md
index dfb4c0f03a..9248839270 100644
--- a/packages/babel-plugin-transform-flow-strip-types/README.md
+++ b/packages/babel-plugin-transform-flow-strip-types/README.md
@@ -55,4 +55,5 @@ require("babel-core").transform("code", {
 `boolean`, defaults to `false`.
 
 Setting this to true will only strip annotations and declarations from files
-that contain the `// @flow` directive.
+that contain the `// @flow` directive. It will also throw errors for any Flow
+annotations found in files without the directive.
diff --git a/packages/babel-plugin-transform-flow-strip-types/src/index.js b/packages/babel-plugin-transform-flow-strip-types/src/index.js
index c0acf431b4..1bec2a5745 100644
--- a/packages/babel-plugin-transform-flow-strip-types/src/index.js
+++ b/packages/babel-plugin-transform-flow-strip-types/src/index.js
@@ -47,7 +47,13 @@ export default function({ types: t }) {
       },
 
       Flow(path) {
-        if (skipStrip) return;
+        if (skipStrip) {
+          throw path.buildCodeFrameError(
+            "A @flow directive is required when using Flow annotations with " +
+              "babel-preset-react or the `requireDirective` option.",
+          );
+        }
+
         path.remove();
       },
 
diff --git a/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-does-not-throw-with-directive/actual.js b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-does-not-throw-with-directive/actual.js
new file mode 100644
index 0000000000..88aebda63c
--- /dev/null
+++ b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-does-not-throw-with-directive/actual.js
@@ -0,0 +1 @@
+function foo(numVal, strVal) {}
diff --git a/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-does-not-throw-with-directive/expected.js b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-does-not-throw-with-directive/expected.js
new file mode 100644
index 0000000000..88aebda63c
--- /dev/null
+++ b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-does-not-throw-with-directive/expected.js
@@ -0,0 +1 @@
+function foo(numVal, strVal) {}
diff --git a/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-ignores-without-directive/actual.js b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-throws-if-found-with-directive/actual.js
similarity index 100%
rename from packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-ignores-without-directive/actual.js
rename to packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-throws-if-found-with-directive/actual.js
diff --git a/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-throws-if-found-with-directive/options.json b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-throws-if-found-with-directive/options.json
new file mode 100644
index 0000000000..03baa59e36
--- /dev/null
+++ b/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-throws-if-found-with-directive/options.json
@@ -0,0 +1,3 @@
+{
+  "throws": "A @flow directive is required when using Flow annotations with babel-preset-react or the `requireDirective` option."
+}
diff --git a/packages/babel-preset-react/README.md b/packages/babel-preset-react/README.md
index 93ce543067..dc25e804c9 100644
--- a/packages/babel-preset-react/README.md
+++ b/packages/babel-preset-react/README.md
@@ -14,8 +14,10 @@ And with the `development` option:
 - [transform-react-jsx-self](https://babeljs.io/docs/plugins/transform-react-jsx-self/)
 - [transform-react-jsx-source](https://babeljs.io/docs/plugins/transform-react-jsx-source/)
 
-Note: Flow annotations and declarations will _only_ be removed in files that
-have the `// @flow ` directive.
+Note: This preset sets the `requireDirective` option on
+`transform-flow-strip-types`. This means Flow annotations and declarations
+will _only_ be removed in files that have a `// @flow ` directive. It will also
+throw errors for any Flow annotations found in files without the directive.
 
 ```js
 // @flow
diff --git a/packages/babel-preset-react/test/fixtures/flow/strip-without-directive/expected.js b/packages/babel-preset-react/test/fixtures/flow/strip-without-directive/expected.js
deleted file mode 100644
index 6bd1f1803c..0000000000
--- a/packages/babel-preset-react/test/fixtures/flow/strip-without-directive/expected.js
+++ /dev/null
@@ -1 +0,0 @@
-function foo(numVal: number, strVal: string) {}
diff --git a/packages/babel-preset-react/test/fixtures/flow/strip-without-directive/actual.js b/packages/babel-preset-react/test/fixtures/flow/throws-without-directive/actual.js
similarity index 100%
rename from packages/babel-preset-react/test/fixtures/flow/strip-without-directive/actual.js
rename to packages/babel-preset-react/test/fixtures/flow/throws-without-directive/actual.js
diff --git a/packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-ignores-without-directive/expected.js b/packages/babel-preset-react/test/fixtures/flow/throws-without-directive/expected.js
similarity index 100%
rename from packages/babel-plugin-transform-flow-strip-types/test/fixtures/requireDirective/true-ignores-without-directive/expected.js
rename to packages/babel-preset-react/test/fixtures/flow/throws-without-directive/expected.js
diff --git a/packages/babel-preset-react/test/fixtures/flow/throws-without-directive/options.json b/packages/babel-preset-react/test/fixtures/flow/throws-without-directive/options.json
new file mode 100644
index 0000000000..03baa59e36
--- /dev/null
+++ b/packages/babel-preset-react/test/fixtures/flow/throws-without-directive/options.json
@@ -0,0 +1,3 @@
+{
+  "throws": "A @flow directive is required when using Flow annotations with babel-preset-react or the `requireDirective` option."
+}

From 2a83867436dd683383b749f85e0831b4b950ae7c Mon Sep 17 00:00:00 2001
From: Brian Ng <bng412@gmail.com>
Date: Fri, 4 Aug 2017 09:32:36 -0500
Subject: [PATCH 3/3] Fixes from review

---
 packages/babel-preset-react/README.md    | 31 ++++++++++++++++++++++++
 packages/babel-preset-react/package.json |  1 -
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/packages/babel-preset-react/README.md b/packages/babel-preset-react/README.md
index dc25e804c9..049cad9add 100644
--- a/packages/babel-preset-react/README.md
+++ b/packages/babel-preset-react/README.md
@@ -87,3 +87,34 @@ require("babel-core").transform("code", {
 `boolean`, defaults to `false`.
 
 Toggles plugins that aid in development, such as [`babel-plugin-transform-react-jsx-self`](https://babeljs.io/docs/plugins/transform-react-jsx-self/) and [`babel-plugin-transform-react-jsx-source`](https://babeljs.io/docs/plugins/transform-react-jsx-source/).
+
+This is useful when combined with either a `babelrc.js` or [env option in a .babelrc](https://babeljs.io/docs/usage/babelrc/#env-option) configuration:
+
+#### babelrc.js
+
+```js
+module.exports = {
+  presets: [
+    ["react", {
+      development: process.env.BABEL_ENV === "development"
+    }],
+  ],
+}
+```
+
+#### .babelrc
+
+> Note: the `env` option will likely get deprecated soon
+
+```json
+{
+  "presets": ["react"],
+  "env": {
+    "development": {
+      "presets": [
+        ["react", { "development": true }]
+      ]
+    }
+  }
+}
+```
diff --git a/packages/babel-preset-react/package.json b/packages/babel-preset-react/package.json
index fb48ed3c27..ab3feff62e 100644
--- a/packages/babel-preset-react/package.json
+++ b/packages/babel-preset-react/package.json
@@ -13,7 +13,6 @@
     "babel-plugin-transform-react-display-name": "7.0.0-alpha.18",
     "babel-plugin-transform-react-jsx": "7.0.0-alpha.18",
     "babel-plugin-transform-react-jsx-self": "7.0.0-alpha.18",
-    "babel-plugin-transform-react-jsx-source": "7.0.0-alpha.18",
     "babel-plugin-transform-react-jsx-source": "7.0.0-alpha.18"
   },
   "devDependencies": {