Merged master and resolved conflicts

.codesandbox/ci.json

@@ -1,6 +1,6 @@
 {
   "packages": ["packages/react", "packages/react-dom", "packages/scheduler"],
-  "buildCommand": "build --type=NODE react/index,react-dom/index,react-dom/server,react-dom/test-utils,scheduler/index,scheduler/tracing",
+  "buildCommand": "build --type=NODE react/index,react-dom/index,react-dom/server,react-dom/test-utils,scheduler/index,scheduler/unstable_no_dom,scheduler/tracing",
   "publishDirectory": {
     "react": "build/node_modules/react",
     "react-dom": "build/node_modules/react-dom",

.gitignore

@@ -8,6 +8,7 @@ scripts/flow/*/.flowconfig
 _SpecRunner.html
 __benchmarks__
 build/
+build2/
 remote-repo/
 coverage/
 .module-cache

package.json

@@ -106,7 +106,8 @@
   },
   "scripts": {
     "build": "node ./scripts/rollup/build.js",
-    "build-for-devtools": "cross-env RELEASE_CHANNEL=experimental yarn build react/index,react-dom,react-is,react-debug-tools,scheduler,react-test-renderer,react-refresh",
+    "build-combined": "node ./scripts/rollup/build-all-release-channels.js",
+    "build-for-devtools": "cross-env RELEASE_CHANNEL=experimental yarn build-combined react/index,react-dom,react-is,react-debug-tools,scheduler,react-test-renderer,react-refresh",
     "build-for-devtools-dev": "yarn build-for-devtools --type=NODE_DEV",
     "build-for-devtools-prod": "yarn build-for-devtools --type=NODE_PROD",
     "linc": "node ./scripts/tasks/linc.js",

packages/eslint-plugin-react-hooks/__tests__/ESLintRuleExhaustiveDeps-test.js

@@ -1692,6 +1692,42 @@ const tests = {
         },
       ],
     },
+    {
+      code: normalizeIndent`
+        function MyComponent() {
+          useEffect()
+          useLayoutEffect()
+          useCallback()
+          useMemo()
+        }
+      `,
+      errors: [
+        {
+          message:
+            'React Hook useEffect requires an effect callback. ' +
+            'Did you forget to pass a callback to the hook?',
+          suggestions: undefined,
+        },
+        {
+          message:
+            'React Hook useLayoutEffect requires an effect callback. ' +
+            'Did you forget to pass a callback to the hook?',
+          suggestions: undefined,
+        },
+        {
+          message:
+            'React Hook useCallback requires an effect callback. ' +
+            'Did you forget to pass a callback to the hook?',
+          suggestions: undefined,
+        },
+        {
+          message:
+            'React Hook useMemo requires an effect callback. ' +
+            'Did you forget to pass a callback to the hook?',
+          suggestions: undefined,
+        },
+      ],
+    },
     {
       // Regression test
       code: normalizeIndent`

packages/eslint-plugin-react-hooks/src/ExhaustiveDeps.js

@@ -1119,6 +1119,19 @@ export default {
       const declaredDependenciesNode = node.arguments[callbackIndex + 1];
       const isEffect = /Effect($|[^a-z])/g.test(reactiveHookName);
 
+      // Check whether a callback is supplied. If there is no callback supplied
+      // then the hook will not work and React will throw a TypeError.
+      // So no need to check for dependency inclusion.
+      if (!callback) {
+        reportProblem({
+          node: reactiveHook,
+          message:
+            `React Hook ${reactiveHookName} requires an effect callback. ` +
+            `Did you forget to pass a callback to the hook?`,
+        });
+        return;
+      }
+
       // Check the declared dependencies for this reactive hook. If there is no
       // second argument then the reactive callback will re-run on every render.
       // So no need to check for dependency inclusion.

packages/react-debug-tools/src/ReactDebugHooks.js

@@ -73,6 +73,10 @@ function getPrimitiveStackCache(): Map<string, Array<any>> {
       Dispatcher.useState(null);
       Dispatcher.useReducer((s, a) => s, null);
       Dispatcher.useRef(null);
+      if (typeof Dispatcher.useCacheRefresh === 'function') {
+        // This type check is for Flow only.
+        Dispatcher.useCacheRefresh();
+      }
       Dispatcher.useLayoutEffect(() => {});
       Dispatcher.useEffect(() => {});
       Dispatcher.useImperativeHandle(undefined, () => null);
@@ -171,6 +175,16 @@ function useRef<T>(initialValue: T): {|current: T|} {
   return ref;
 }
 
+function useCacheRefresh(): () => void {
+  const hook = nextHook();
+  hookLog.push({
+    primitive: 'CacheRefresh',
+    stackError: new Error(),
+    value: hook !== null ? hook.memoizedState : function refresh() {},
+  });
+  return () => {};
+}
+
 function useLayoutEffect(
   create: () => (() => void) | void,
   inputs: Array<mixed> | void | null,
@@ -305,6 +319,7 @@ function useOpaqueIdentifier(): OpaqueIDType | void {
 const Dispatcher: DispatcherType = {
   getCacheForType,
   readContext,
+  useCacheRefresh,
   useCallback,
   useContext,
   useEffect,