Lint rule to detect unminified errors

.eslintrc.js

@@ -127,6 +127,41 @@ module.exports = {
   },
 
   overrides: [
+    {
+      // By default, anything error message that appears the packages directory
+      // must have a corresponding error code. The exceptions are defined
+      // in the next override entry.
+      files: ['packages/**/*.js'],
+      rules: {
+        'react-internal/prod-error-codes': ERROR,
+      },
+    },
+    {
+      // These are files where it's OK to have unminified error messages. These
+      // are environments where bundle size isn't a concern, like tests
+      // or Node.
+      files: [
+        'packages/react-dom/src/test-utils/**/*.js',
+        'packages/react-devtools-shared/**/*.js',
+        'packages/react-noop-renderer/**/*.js',
+        'packages/react-pg/**/*.js',
+        'packages/react-fs/**/*.js',
+        'packages/react-refresh/**/*.js',
+        'packages/react-server-dom-webpack/**/*.js',
+        'packages/react-test-renderer/**/*.js',
+        'packages/react-debug-tools/**/*.js',
+        'packages/react-devtools-extensions/**/*.js',
+        'packages/react-devtools-scheduling-profiler/**/*.js',
+        'packages/react-native-renderer/**/*.js',
+        'packages/eslint-plugin-react-hooks/**/*.js',
+        'packages/jest-react/**/*.js',
+        'packages/**/__tests__/*.js',
+        'packages/**/npm/*.js',
+      ],
+      rules: {
+        'react-internal/prod-error-codes': OFF,
+      },
+    },
     {
       // We apply these settings to files that we ship through npm.
       // They must be ES5.

packages/jest-react/src/JestReact.js

@@ -7,7 +7,6 @@
 
 import {REACT_ELEMENT_TYPE, REACT_FRAGMENT_TYPE} from 'shared/ReactSymbols';
 
-import invariant from 'shared/invariant';
 import isArray from 'shared/isArray';
 
 export {act} from './internalAct';
@@ -31,11 +30,12 @@ function captureAssertion(fn) {
 function assertYieldsWereCleared(root) {
   const Scheduler = root._Scheduler;
   const actualYields = Scheduler.unstable_clearYields();
-  invariant(
-    actualYields.length === 0,
-    'Log of yielded values is not empty. ' +
-      'Call expect(ReactTestRenderer).unstable_toHaveYielded(...) first.',
-  );
+  if (actualYields.length !== 0) {
+    throw new Error(
+      'Log of yielded values is not empty. ' +
+        'Call expect(ReactTestRenderer).unstable_toHaveYielded(...) first.',
+    );
+  }
 }
 
 export function unstable_toMatchRenderedOutput(root, expectedJSX) {

packages/react-art/src/ReactARTHostConfig.js

@@ -433,25 +433,25 @@ export function clearContainer(container) {
 }
 
 export function getInstanceFromNode(node) {
-  throw new Error('Not yet implemented.');
+  throw new Error('Not implemented.');
 }
 
 export function isOpaqueHydratingObject(value: mixed): boolean {
-  throw new Error('Not yet implemented');
+  throw new Error('Not implemented.');
 }
 
 export function makeOpaqueHydratingObject(
   attemptToReadValue: () => void,
 ): OpaqueIDType {
-  throw new Error('Not yet implemented.');
+  throw new Error('Not implemented.');
 }
 
 export function makeClientId(): OpaqueIDType {
-  throw new Error('Not yet implemented');
+  throw new Error('Not implemented.');
 }
 
 export function makeClientIdInDEV(warnOnAccessInDEV: () => void): OpaqueIDType {
-  throw new Error('Not yet implemented');
+  throw new Error('Not implemented.');
 }
 
 export function beforeActiveInstanceBlur(internalInstanceHandle: Object) {

packages/react-cache/src/ReactCacheOld.js

@@ -49,6 +49,8 @@ const ReactCurrentDispatcher =
 function readContext(Context) {
   const dispatcher = ReactCurrentDispatcher.current;
   if (dispatcher === null) {
+    // This wasn't being minified but we're going to retire this package anyway.
+    // eslint-disable-next-line react-internal/prod-error-codes
     throw new Error(
       'react-cache: read and preload may only be called from within a ' +
         "component's render. They are not supported in event handlers or " +

packages/react-client/src/ReactFlightClient.js

@@ -397,6 +397,7 @@ export function resolveError(
   message: string,
   stack: string,
 ): void {
+  // eslint-disable-next-line react-internal/prod-error-codes
   const error = new Error(message);
   error.stack = stack;
   const chunks = response._chunks;

packages/react-client/src/ReactFlightClientHostConfigNoStream.js

@@ -12,19 +12,22 @@ export type StringDecoder = void;
 export const supportsBinaryStreams = false;
 
 export function createStringDecoder(): void {
+  // eslint-disable-next-line react-internal/prod-error-codes
   throw new Error('Should never be called');
 }
 
 export function readPartialStringChunk(
   decoder: StringDecoder,
   buffer: Uint8Array,
 ): string {
+  // eslint-disable-next-line react-internal/prod-error-codes
   throw new Error('Should never be called');
 }
 
 export function readFinalStringChunk(
   decoder: StringDecoder,
   buffer: Uint8Array,
 ): string {
+  // eslint-disable-next-line react-internal/prod-error-codes
   throw new Error('Should never be called');
 }

packages/react-fetch/src/ReactFetchBrowser.js

@@ -129,6 +129,7 @@ function preloadRecord(url: string, options: mixed): Record {
       if (options.method || options.body || options.signal) {
         // TODO: wire up our own cancellation mechanism.
         // TODO: figure out what to do with POST.
+        // eslint-disable-next-line react-internal/prod-error-codes
         throw Error('Unsupported option');
       }
     }

packages/react-fetch/src/ReactFetchNode.js

@@ -177,6 +177,7 @@ function preloadRecord(url: string, options: mixed): Record<FetchResponse> {
       if (options.method || options.body || options.signal) {
         // TODO: wire up our own cancellation mechanism.
         // TODO: figure out what to do with POST.
+        // eslint-disable-next-line react-internal/prod-error-codes
         throw Error('Unsupported option');
       }
     }

packages/react-reconciler/src/ReactFiberBeginWork.new.js

@@ -1050,6 +1050,7 @@ function updateClassComponent(
       case true: {
         workInProgress.flags |= DidCapture;
         workInProgress.flags |= ShouldCapture;
+        // eslint-disable-next-line react-internal/prod-error-codes
         const error = new Error('Simulated error coming from DevTools');
         const lane = pickArbitraryLane(renderLanes);
         workInProgress.lanes = mergeLanes(workInProgress.lanes, lane);
@@ -3317,6 +3318,7 @@ function remountFiber(
   if (__DEV__) {
     const returnFiber = oldWorkInProgress.return;
     if (returnFiber === null) {
+      // eslint-disable-next-line react-internal/prod-error-codes
       throw new Error('Cannot swap the root fiber.');
     }
 
@@ -3337,11 +3339,13 @@ function remountFiber(
     } else {
       let prevSibling = returnFiber.child;
       if (prevSibling === null) {
+        // eslint-disable-next-line react-internal/prod-error-codes
         throw new Error('Expected parent to have a child.');
       }
       while (prevSibling.sibling !== oldWorkInProgress) {
         prevSibling = prevSibling.sibling;
         if (prevSibling === null) {
+          // eslint-disable-next-line react-internal/prod-error-codes
           throw new Error('Expected to find the previous sibling.');
         }
       }

packages/react-reconciler/src/ReactFiberBeginWork.old.js

@@ -1050,6 +1050,7 @@ function updateClassComponent(
       case true: {
         workInProgress.flags |= DidCapture;
         workInProgress.flags |= ShouldCapture;
+        // eslint-disable-next-line react-internal/prod-error-codes
         const error = new Error('Simulated error coming from DevTools');
         const lane = pickArbitraryLane(renderLanes);
         workInProgress.lanes = mergeLanes(workInProgress.lanes, lane);
@@ -3317,6 +3318,7 @@ function remountFiber(
   if (__DEV__) {
     const returnFiber = oldWorkInProgress.return;
     if (returnFiber === null) {
+      // eslint-disable-next-line react-internal/prod-error-codes
       throw new Error('Cannot swap the root fiber.');
     }
 
@@ -3337,11 +3339,13 @@ function remountFiber(
     } else {
       let prevSibling = returnFiber.child;
       if (prevSibling === null) {
+        // eslint-disable-next-line react-internal/prod-error-codes
         throw new Error('Expected parent to have a child.');
       }
       while (prevSibling.sibling !== oldWorkInProgress) {
         prevSibling = prevSibling.sibling;
         if (prevSibling === null) {
+          // eslint-disable-next-line react-internal/prod-error-codes
           throw new Error('Expected to find the previous sibling.');
         }
       }

packages/react-reconciler/src/ReactFiberHooks.new.js

@@ -1532,6 +1532,7 @@ function pushEffect(tag, create, destroy, deps) {
 let stackContainsErrorMessage: boolean | null = null;
 
 function getCallerStackFrame(): string {
+  // eslint-disable-next-line react-internal/prod-error-codes
   const stackFrames = new Error('Error message').stack.split('\n');
 
   // Some browsers (e.g. Chrome) include the error message in the stack

packages/react-reconciler/src/ReactFiberHooks.old.js

@@ -1532,6 +1532,7 @@ function pushEffect(tag, create, destroy, deps) {
 let stackContainsErrorMessage: boolean | null = null;
 
 function getCallerStackFrame(): string {
+  // eslint-disable-next-line react-internal/prod-error-codes
   const stackFrames = new Error('Error message').stack.split('\n');
 
   // Some browsers (e.g. Chrome) include the error message in the stack

packages/react-reconciler/src/ReactFiberHotReloading.new.js

@@ -7,6 +7,8 @@
  * @flow
  */
 
+/* eslint-disable react-internal/prod-error-codes */
+
 import type {ReactElement} from 'shared/ReactElementType';
 import type {Fiber} from './ReactInternalTypes';
 import type {FiberRoot} from './ReactInternalTypes';

packages/react-reconciler/src/ReactFiberHotReloading.old.js

@@ -7,6 +7,8 @@
  * @flow
  */
 
+/* eslint-disable react-internal/prod-error-codes */
+
 import type {ReactElement} from 'shared/ReactElementType';
 import type {Fiber} from './ReactInternalTypes';
 import type {FiberRoot} from './ReactInternalTypes';

packages/react-reconciler/src/ReactFiberThrow.new.js

@@ -474,7 +474,8 @@ function throwException(
       return;
     } else {
       // No boundary was found. Fallthrough to error mode.
-      // TODO: Use invariant so the message is stripped in prod?
+      // TODO: We should never call getComponentNameFromFiber in production.
+      // Log a warning or something to prevent us from accidentally bundling it.
       value = new Error(
         (getComponentNameFromFiber(sourceFiber) || 'A React component') +
           ' suspended while rendering, but no fallback UI was specified.\n' +

packages/react-reconciler/src/ReactFiberThrow.old.js

@@ -474,7 +474,8 @@ function throwException(
       return;
     } else {
       // No boundary was found. Fallthrough to error mode.
-      // TODO: Use invariant so the message is stripped in prod?
+      // TODO: We should never call getComponentNameFromFiber in production.
+      // Log a warning or something to prevent us from accidentally bundling it.
       value = new Error(
         (getComponentNameFromFiber(sourceFiber) || 'A React component') +
           ' suspended while rendering, but no fallback UI was specified.\n' +

packages/react/unstable-shared-subset.js

@@ -7,6 +7,7 @@
  * @flow
  */
 
+// eslint-disable-next-line react-internal/prod-error-codes
 throw new Error(
   'This entry point is not yet supported outside of experimental channels',
 );

packages/scheduler/src/forks/SchedulerMock.js

@@ -7,6 +7,7 @@
  */
 
 /* eslint-disable no-var */
+/* eslint-disable react-internal/prod-error-codes */
 
 import {
   enableSchedulerDebugging,

packages/shared/checkPropTypes.js

@@ -52,6 +52,7 @@ export default function checkPropTypes(
           // This is intentionally an invariant that gets caught. It's the same
           // behavior as without this statement except with a better message.
           if (typeof typeSpecs[typeSpecName] !== 'function') {
+            // eslint-disable-next-line react-internal/prod-error-codes
             const err = Error(
               (componentName || 'React class') +
                 ': ' +

packages/shared/invariant.js

@@ -18,6 +18,7 @@
  */
 
 export default function invariant(condition, format, a, b, c, d, e, f) {
+  // eslint-disable-next-line react-internal/prod-error-codes
   throw new Error(
     'Internal React error: invariant() is meant to be replaced at compile ' +
       'time. There is no runtime version.',

packages/shared/invokeGuardedCallbackImpl.js

@@ -201,6 +201,7 @@ if (__DEV__) {
       if (didCall && didError) {
         if (!didSetError) {
           // The callback errored, but the error event never fired.
+          // eslint-disable-next-line react-internal/prod-error-codes
           error = new Error(
             'An error was thrown inside one of your components, but React ' +
               "doesn't know what it was. This is likely due to browser " +
@@ -212,6 +213,7 @@ if (__DEV__) {
               'actually an issue with React, please file an issue.',
           );
         } else if (isCrossOriginError) {
+          // eslint-disable-next-line react-internal/prod-error-codes
           error = new Error(
             "A cross-origin error was thrown. React doesn't have access to " +
               'the actual error object in development. ' +

scripts/error-codes/__tests__/__snapshots__/transform-error-messages.js.snap

@@ -1,5 +1,10 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`error transform handles escaped backticks in template string 1`] = `
+"import _formatProdErrorMessage from \\"shared/formatProdErrorMessage\\";
+Error(__DEV__ ? \\"Expected \`\\" + listener + \\"\` listener to be a function, instead got a value of \`\\" + type + \\"\` type.\\" : _formatProdErrorMessage(231, listener, type));"
+`;
+
 exports[`error transform should correctly transform invariants that are not in the error codes map 1`] = `
 "import invariant from 'shared/invariant';
 
@@ -18,6 +23,21 @@ if (!condition) {
 }"
 `;
 
+exports[`error transform should not touch other calls or new expressions 1`] = `
+"new NotAnError();
+NotAnError();"
+`;
+
+exports[`error transform should replace error constructors (no new) 1`] = `
+"import _formatProdErrorMessage from \\"shared/formatProdErrorMessage\\";
+Error(__DEV__ ? 'Do not override existing functions.' : _formatProdErrorMessage(16));"
+`;
+
+exports[`error transform should replace error constructors 1`] = `
+"import _formatProdErrorMessage from \\"shared/formatProdErrorMessage\\";
+Error(__DEV__ ? 'Do not override existing functions.' : _formatProdErrorMessage(16));"
+`;
+
 exports[`error transform should replace simple invariant calls 1`] = `
 "import _formatProdErrorMessage from \\"shared/formatProdErrorMessage\\";
 import invariant from 'shared/invariant';
@@ -29,6 +49,21 @@ if (!condition) {
 }"
 `;
 
+exports[`error transform should support error constructors with concatenated messages 1`] = `
+"import _formatProdErrorMessage from \\"shared/formatProdErrorMessage\\";
+Error(__DEV__ ? \\"Expected \\" + foo + \\" target to \\" + (\\"be an array; got \\" + bar) : _formatProdErrorMessage(7, foo, bar));"
+`;
+
+exports[`error transform should support interpolating arguments with concatenation 1`] = `
+"import _formatProdErrorMessage from \\"shared/formatProdErrorMessage\\";
+Error(__DEV__ ? 'Expected ' + foo + ' target to be an array; got ' + bar : _formatProdErrorMessage(7, foo, bar));"
+`;
+
+exports[`error transform should support interpolating arguments with template strings 1`] = `
+"import _formatProdErrorMessage from \\"shared/formatProdErrorMessage\\";
+Error(__DEV__ ? \\"Expected \\" + foo + \\" target to be an array; got \\" + bar : _formatProdErrorMessage(7, foo, bar));"
+`;
+
 exports[`error transform should support invariant calls with a concatenated template string and args 1`] = `
 "import _formatProdErrorMessage from \\"shared/formatProdErrorMessage\\";
 import invariant from 'shared/invariant';