Remove special casing of toString values when enableTrustedTypesIntegration

As far as I can tell, we only toString in user space because of IE8/9.

We don't really support IE8/9 anymore and by the time this flag is on,
we should be able to deprecate it.

Unless this is also an issue in IE11. I haven't tested yet.

Author: sebmarkbage

packages/react-dom/src/client/DOMPropertyOperations.js

@@ -16,8 +16,10 @@ import {
   OVERLOADED_BOOLEAN,
 } from '../shared/DOMProperty';
 import sanitizeURL from '../shared/sanitizeURL';
-import {toStringOrTrustedType} from './ToStringValue';
-import {disableJavaScriptURLs} from 'shared/ReactFeatureFlags';
+import {
+  disableJavaScriptURLs,
+  enableTrustedTypesIntegration,
+} from 'shared/ReactFeatureFlags';
 import {setAttribute, setAttributeNS} from './setAttribute';
 
 import type {PropertyInfo} from '../shared/DOMProperty';
@@ -144,7 +146,11 @@ export function setValueForProperty(
       if (value === null) {
         node.removeAttribute(attributeName);
       } else {
-        setAttribute(node, attributeName, toStringOrTrustedType(value));
+        setAttribute(
+          node,
+          attributeName,
+          enableTrustedTypesIntegration ? value : value + '',
+        );
       }
     }
     return;
@@ -176,7 +182,9 @@ export function setValueForProperty(
     } else {
       // `setAttribute` with objects becomes only `[object]` in IE8/9,
       // ('' + value) makes it output the correct toString()-value.
-      attributeValue = toStringOrTrustedType(value);
+      if (!enableTrustedTypesIntegration) {
+        attributeValue = value + '';
+      }
       if (propertyInfo.sanitizeURL) {
         sanitizeURL(attributeValue.toString());
       }

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

@@ -7,8 +7,6 @@
  * @flow
  */
 
-import {enableTrustedTypesIntegration} from 'shared/ReactFeatureFlags';
-
 export opaque type ToStringValue =
   | boolean
   | number
@@ -43,28 +41,3 @@ export opaque type TrustedValue: {toString(): string, valueOf(): string} = {
   toString(): string,
   valueOf(): string,
 };
-
-/**
- * We allow passing objects with toString method as element attributes or in dangerouslySetInnerHTML
- * and we do validations that the value is safe. Once we do validation we want to use the validated
- * value instead of the object (because object.toString may return something else on next call).
- *
- * If application uses Trusted Types we don't stringify trusted values, but preserve them as objects.
- */
-export let toStringOrTrustedType: any => string | TrustedValue = toString;
-if (enableTrustedTypesIntegration && typeof trustedTypes !== 'undefined') {
-  toStringOrTrustedType = value => {
-    if (
-      typeof value === 'object' &&
-      (trustedTypes.isHTML(value) ||
-        trustedTypes.isScript(value) ||
-        trustedTypes.isScriptURL(value) ||
-        /* TrustedURLs are deprecated and will be removed soon: https://github.com/WICG/trusted-types/pull/204 */
-        (trustedTypes.isURL && trustedTypes.isURL(value)))
-    ) {
-      // Pass Trusted Types through.
-      return value;
-    }
-    return toString(value);
-  };
-}