util: remove unreachable defensive coding

Trott · danielleadams · commit bff201a66d1c · 2021-01-12T07:10:37.000-05:00
Now that we are using primordials in the first part of isIdenticalTypedArrayType(), the defensive coding to get the correct result (when Symbol.toStringTag is manipulated) is no longer reachable or necessary. Remove the code. Refs: https://coverage.nodejs.org/coverage-873d21cdc1266273/lib/internal/util/comparisons.js.html#L135 PR-URL: #36744 Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de> Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
diff --git a/lib/internal/util/comparisons.js b/lib/internal/util/comparisons.js
@@ -44,15 +44,6 @@ const {
   isSymbolObject,
   isFloat32Array,
   isFloat64Array,
-  isUint8Array,
-  isUint8ClampedArray,
-  isUint16Array,
-  isUint32Array,
-  isInt8Array,
-  isInt16Array,
-  isInt32Array,
-  isBigInt64Array,
-  isBigUint64Array
 } = types;
 const {
   getOwnNonIndexProperties,
@@ -126,38 +117,6 @@ function isEqualBoxedPrimitive(val1, val2) {
   assert.fail(`Unknown boxed type ${val1}`);
 }
 
-function isIdenticalTypedArrayType(a, b) {
-  // Fast path to reduce type checks in the common case.
-  const check = types[`is${TypedArrayPrototypeGetSymbolToStringTag(a)}`];
-  if (check !== undefined && check(a)) {
-    return check(b);
-  }
-  // Manipulated Symbol.toStringTag.
-  for (const check of [
-    isUint16Array,
-    isUint32Array,
-    isInt8Array,
-    isInt16Array,
-    isInt32Array,
-    isFloat32Array,
-    isFloat64Array,
-    isBigInt64Array,
-    isBigUint64Array,
-    isUint8ClampedArray,
-    isUint8Array
-  ]) {
-    if (check(a)) {
-      return check(b);
-    }
-  }
-  /* c8 ignore next 4 */
-  assert.fail(
-    'Unknown TypedArray type checking ' +
-    `${TypedArrayPrototypeGetSymbolToStringTag(a)} ${a}\n` +
-    `and ${TypedArrayPrototypeGetSymbolToStringTag(b)} ${b}`
-  );
-}
-
 // Notes: Type tags are historical [[Class]] properties that can be set by
 // FunctionTemplate::SetClassName() in C++ or Symbol.toStringTag in JS
 // and retrieved using Object.prototype.toString.call(obj) in JS
@@ -241,8 +200,10 @@ function innerDeepEqual(val1, val2, strict, memos) {
       return false;
     }
   } else if (isArrayBufferView(val1)) {
-    if (!isIdenticalTypedArrayType(val1, val2))
+    if (TypedArrayPrototypeGetSymbolToStringTag(val1) !==
+        TypedArrayPrototypeGetSymbolToStringTag(val2)) {
       return false;
+    }
     if (!strict && (isFloat32Array(val1) || isFloat64Array(val1))) {
       if (!areSimilarFloatArrays(val1, val2)) {
         return false;
