Add support for rendering BigInt (facebook#24580)

Author: eps1lon

packages/react-devtools-shell/src/app/InspectableElements/UnserializableProps.js

@@ -58,5 +58,9 @@ export default function UnserializableProps(): React.Node {
 }
 
 function ChildComponent(props: any) {
-  return null;
+  return (
+    <>
+      <div>{props.bigInt}</div>
+    </>
+  );
 }

packages/react-dom-bindings/src/client/ReactDOMComponent.js

@@ -66,6 +66,7 @@ import {validateProperties as validateUnknownProperties} from '../shared/ReactDO
 import sanitizeURL from '../shared/sanitizeURL';
 
 import {
+  enableBigIntSupport,
   enableCustomElementPropertySupport,
   enableClientRenderFallbackOnTextMismatch,
   enableFormActions,
@@ -326,7 +327,7 @@ function normalizeMarkupForTextOrAttribute(markup: mixed): string {
 
 export function checkForUnmatchedText(
   serverText: string,
-  clientText: string | number,
+  clientText: string | number | bigint,
   isConcurrentMode: boolean,
   shouldWarnDev: boolean,
 ) {
@@ -397,12 +398,17 @@ function setProp(
         if (canSetTextContent) {
           setTextContent(domElement, value);
         }
-      } else if (typeof value === 'number') {
+      } else if (
+        typeof value === 'number' ||
+        (enableBigIntSupport && typeof value === 'bigint')
+      ) {
         if (__DEV__) {
+          // $FlowFixMe[unsafe-addition] Flow doesn't want us to use `+` operator with string and bigint
           validateTextNesting('' + value, tag);
         }
         const canSetTextContent = tag !== 'body';
         if (canSetTextContent) {
+          // $FlowFixMe[unsafe-addition] Flow doesn't want us to use `+` operator with string and bigint
           setTextContent(domElement, '' + value);
         }
       }
@@ -955,7 +961,11 @@ function setPropOnCustomElement(
     case 'children': {
       if (typeof value === 'string') {
         setTextContent(domElement, value);
-      } else if (typeof value === 'number') {
+      } else if (
+        typeof value === 'number' ||
+        (enableBigIntSupport && typeof value === 'bigint')
+      ) {
+        // $FlowFixMe[unsafe-addition] Flow doesn't want us to use `+` operator with string and bigint
         setTextContent(domElement, '' + value);
       }
       break;
@@ -2817,7 +2827,12 @@ export function diffHydratedProperties(
   // even listeners these nodes might be wired up to.
   // TODO: Warn if there is more than a single textNode as a child.
   // TODO: Should we use domElement.firstChild.nodeValue to compare?
-  if (typeof children === 'string' || typeof children === 'number') {
+  if (
+    typeof children === 'string' ||
+    typeof children === 'number' ||
+    (enableBigIntSupport && typeof children === 'bigint')
+  ) {
+    // $FlowFixMe[unsafe-addition] Flow doesn't want us to use `+` operator with string and bigint
     if (domElement.textContent !== '' + children) {
       if (props.suppressHydrationWarning !== true) {
         checkForUnmatchedText(

packages/react-dom-bindings/src/client/ReactDOMOption.js

@@ -8,6 +8,7 @@
  */
 
 import {Children} from 'react';
+import {enableBigIntSupport} from 'shared/ReactFeatureFlags';
 
 let didWarnSelectedSetOnOption = false;
 let didWarnInvalidChild = false;
@@ -26,7 +27,11 @@ export function validateOptionProps(element: Element, props: Object) {
           if (child == null) {
             return;
           }
-          if (typeof child === 'string' || typeof child === 'number') {
+          if (
+            typeof child === 'string' ||
+            typeof child === 'number' ||
+            (enableBigIntSupport && typeof child === 'bigint')
+          ) {
             return;
           }
           if (!didWarnInvalidChild) {

packages/react-dom-bindings/src/client/ReactFiberConfigDOM.js

@@ -89,6 +89,7 @@ import {
 import {retryIfBlockedOn} from '../events/ReactDOMEventReplaying';
 
 import {
+  enableBigIntSupport,
   enableCreateEventHandleAPI,
   enableScopeAPI,
   enableFloat,
@@ -548,6 +549,7 @@ export function shouldSetTextContent(type: string, props: Props): boolean {
     type === 'noscript' ||
     typeof props.children === 'string' ||
     typeof props.children === 'number' ||
+    (enableBigIntSupport && typeof props.children === 'bigint') ||
     (typeof props.dangerouslySetInnerHTML === 'object' &&
       props.dangerouslySetInnerHTML !== null &&
       props.dangerouslySetInnerHTML.__html != null)

packages/react-dom-bindings/src/client/ToStringValue.js

@@ -8,10 +8,12 @@
  */
 
 import {checkFormFieldValueStringCoercion} from 'shared/CheckStringCoercion';
+import {enableBigIntSupport} from 'shared/ReactFeatureFlags';
 
 export opaque type ToStringValue =
   | boolean
   | number
+  | bigint
   | Object
   | string
   | null
@@ -28,6 +30,12 @@ export function toString(value: ToStringValue): string {
 
 export function getToStringValue(value: mixed): ToStringValue {
   switch (typeof value) {
+    case 'bigint':
+      if (!enableBigIntSupport) {
+        // bigint is assigned as empty string
+        return '';
+      }
+    // fallthrough for BigInt support
     case 'boolean':
     case 'number':
     case 'string':

packages/react-dom-bindings/src/server/ReactFizzConfigDOM.js

@@ -28,6 +28,7 @@ import {
 import {Children} from 'react';
 
 import {
+  enableBigIntSupport,
   enableFilterEmptyStringAttributesDOM,
   enableCustomElementPropertySupport,
   enableFloat,
@@ -1626,7 +1627,9 @@ function flattenOptionChildren(children: mixed): string {
       if (
         !didWarnInvalidOptionChildren &&
         typeof child !== 'string' &&
-        typeof child !== 'number'
+        typeof child !== 'number' &&
+        ((enableBigIntSupport && typeof child !== 'bigint') ||
+          !enableBigIntSupport)
       ) {
         didWarnInvalidOptionChildren = true;
         console.error(
@@ -2960,36 +2963,40 @@ function pushTitle(
 
       if (Array.isArray(children) && children.length > 1) {
         console.error(
-          'React expects the `children` prop of <title> tags to be a string, number, or object with a novel `toString` method but found an Array with length %s instead.' +
+          'React expects the `children` prop of <title> tags to be a string, number%s, or object with a novel `toString` method but found an Array with length %s instead.' +
             ' Browsers treat all child Nodes of <title> tags as Text content and React expects to be able to convert `children` of <title> tags to a single string value' +
             ' which is why Arrays of length greater than 1 are not supported. When using JSX it can be commong to combine text nodes and value nodes.' +
             ' For example: <title>hello {nameOfUser}</title>. While not immediately apparent, `children` in this case is an Array with length 2. If your `children` prop' +
             ' is using this form try rewriting it using a template string: <title>{`hello ${nameOfUser}`}</title>.',
+          enableBigIntSupport ? ', bigint' : '',
           children.length,
         );
       } else if (typeof child === 'function' || typeof child === 'symbol') {
         const childType =
           typeof child === 'function' ? 'a Function' : 'a Sybmol';
         console.error(
-          'React expect children of <title> tags to be a string, number, or object with a novel `toString` method but found %s instead.' +
+          'React expect children of <title> tags to be a string, number%s, or object with a novel `toString` method but found %s instead.' +
             ' Browsers treat all child Nodes of <title> tags as Text content and React expects to be able to convert children of <title>' +
             ' tags to a single string value.',
+          enableBigIntSupport ? ', bigint' : '',
           childType,
         );
       } else if (child && child.toString === {}.toString) {
         if (child.$$typeof != null) {
           console.error(
-            'React expects the `children` prop of <title> tags to be a string, number, or object with a novel `toString` method but found an object that appears to be' +
+            'React expects the `children` prop of <title> tags to be a string, number%s, or object with a novel `toString` method but found an object that appears to be' +
               ' a React element which never implements a suitable `toString` method. Browsers treat all child Nodes of <title> tags as Text content and React expects to' +
               ' be able to convert children of <title> tags to a single string value which is why rendering React elements is not supported. If the `children` of <title> is' +
               ' a React Component try moving the <title> tag into that component. If the `children` of <title> is some HTML markup change it to be Text only to be valid HTML.',
+            enableBigIntSupport ? ', bigint' : '',
           );
         } else {
           console.error(
-            'React expects the `children` prop of <title> tags to be a string, number, or object with a novel `toString` method but found an object that does not implement' +
+            'React expects the `children` prop of <title> tags to be a string, number%s, or object with a novel `toString` method but found an object that does not implement' +
               ' a suitable `toString` method. Browsers treat all child Nodes of <title> tags as Text content and React expects to be able to convert children of <title> tags' +
               ' to a single string value. Using the default `toString` method available on every object is almost certainly an error. Consider whether the `children` of this <title>' +
               ' is an object in error and change it to a string or number value if so. Otherwise implement a `toString` method that React can use to produce a valid <title>.',
+            enableBigIntSupport ? ', bigint' : '',
           );
         }
       }
@@ -3123,14 +3130,17 @@ function pushStartTitle(
     } else if (
       childForValidation != null &&
       typeof childForValidation !== 'string' &&
-      typeof childForValidation !== 'number'
+      typeof childForValidation !== 'number' &&
+      ((enableBigIntSupport && typeof childForValidation !== 'bigint') ||
+        !enableBigIntSupport)
     ) {
       console.error(
-        'A title element received a value that was not a string or number for children. ' +
+        'A title element received a value that was not a string or number%s for children. ' +
           'In the browser title Elements can only have Text Nodes as children. If ' +
           'the children being rendered output more than a single text node in aggregate the browser ' +
           'will display markup and comments as text in the title and hydration will likely fail and ' +
           'fall back to client rendering',
+        enableBigIntSupport ? ' or bigint' : '',
       );
     }
   }

packages/react-dom-bindings/src/server/escapeTextForBrowser.js

@@ -39,6 +39,7 @@
  */
 
 import {checkHtmlStringCoercion} from 'shared/CheckStringCoercion';
+import {enableBigIntSupport} from 'shared/ReactFeatureFlags';
 
 const matchHtmlRegExp = /["'&<>]/;
 
@@ -106,7 +107,11 @@ function escapeHtml(string: string) {
  * @return {string} An escaped string.
  */
 function escapeTextForBrowser(text: string | number | boolean): string {
-  if (typeof text === 'boolean' || typeof text === 'number') {
+  if (
+    typeof text === 'boolean' ||
+    typeof text === 'number' ||
+    (enableBigIntSupport && typeof text === 'bigint')
+  ) {
     // this shortcircuit helps perf for types that we know will never have
     // special characters, especially given that this function is used often
     // for numeric dom ids.

packages/react-dom/src/__tests__/ReactDOMFiber-test.js

@@ -60,6 +60,17 @@ describe('ReactDOMFiber', () => {
     expect(container.textContent).toEqual('10');
   });
 
+  // @gate enableBigIntSupport
+  it('should render bigints as children', async () => {
+    const Box = ({value}) => <div>{value}</div>;
+
+    await act(async () => {
+      root.render(<Box value={10n} />);
+    });
+
+    expect(container.textContent).toEqual('10');
+  });
+
   it('should call an effect after mount/update (replacing render callback pattern)', async () => {
     function Component() {
       React.useEffect(() => {