assert: improve partialDeepStrictEqual performance and add benchmark

Author: puskin

benchmark/assert/partial-deep-strict-equal.js

@@ -0,0 +1,89 @@
+'use strict';
+
+const common = require('../common.js');
+const assert = require('assert');
+
+const bench = common.createBenchmark(main, {
+  n: [25, 2e2],
+  size: [1e2, 1e4],
+  datasetName: ['objects', 'sets', 'maps', 'arrayBuffers'],
+}, {
+  combinationFilter: (p) => {
+    return p.size === 1e4 && p.n === 25 ||
+           p.size === 1e3 && p.n === 2e2 ||
+           p.size === 1e2 && p.n === 2e3 ||
+           p.size === 1;
+  },
+});
+
+function createObjects(length, depth = 0) {
+  return Array.from({ length }, (n) => ({
+    foo: 'yarp',
+    nope: {
+      bar: '123',
+      a: [1, 2, 3],
+      baz: n,
+      c: {},
+      b: !depth ? createObjects(2, depth + 1) : [],
+    },
+  }));
+}
+
+function createSets(length, depth = 0) {
+  return Array.from({ length }, (n) => new Set([
+    'yarp',
+    {
+      bar: '123',
+      a: [1, 2, 3],
+      baz: n,
+      c: {},
+      b: !depth ? createSets(2, depth + 1) : new Set(),
+    },
+  ]));
+}
+
+function createMaps(length, depth = 0) {
+  return Array.from({ length }, (n) => new Map([
+    ['foo', 'yarp'],
+    ['nope', new Map([
+      ['bar', '123'],
+      ['a', [1, 2, 3]],
+      ['baz', n],
+      ['c', {}],
+      ['b', !depth ? createMaps(2, depth + 1) : new Map()],
+    ])],
+  ]));
+}
+
+function createArrayBuffers(length) {
+  return Array.from({ length }, (n) => {
+    if (n % 2) {
+      return new DataView(new ArrayBuffer(n));
+    }
+    return new ArrayBuffer(n);
+  });
+}
+
+const datasetMappings = {
+  objects: createObjects,
+  sets: createSets,
+  maps: createMaps,
+  arrayBuffers: createArrayBuffers,
+};
+
+function getDatasets(datasetName, size) {
+  return {
+    actual: datasetMappings[datasetName](size),
+    expected: datasetMappings[datasetName](size),
+  };
+}
+
+function main({ size, n, datasetName }) {
+  const { actual, expected } = getDatasets(datasetName, size);
+
+  bench.start();
+  for (let i = 0; i < n; ++i) {
+    assert.partialDeepStrictEqual(actual, expected);
+  }
+  bench.end(n);
+}

lib/assert.js

@@ -23,7 +23,6 @@
 const {
   ArrayBufferIsView,
   ArrayBufferPrototypeGetByteLength,
-  ArrayFrom,
   ArrayIsArray,
   ArrayPrototypeIndexOf,
   ArrayPrototypeJoin,
@@ -395,12 +394,11 @@ function partiallyCompareMaps(actual, expected, comparedObjects) {
   const expectedIterator = FunctionPrototypeCall(SafeMap.prototype[SymbolIterator], expected);
 
   for (const { 0: key, 1: expectedValue } of expectedIterator) {
-    if (!MapPrototypeHas(actual, key)) {
+    const actualValue = MapPrototypeGet(actual, key);
+    if (actualValue === undefined && !MapPrototypeHas(actual, key)) {
       return false;
     }
 
-    const actualValue = MapPrototypeGet(actual, key);
-
     if (!compareBranch(actualValue, expectedValue, comparedObjects)) {
       return false;
     }
@@ -481,18 +479,38 @@ function partiallyCompareSets(actual, expected, comparedObjects) {
 
   if (isDeepEqual === undefined) lazyLoadComparison();
 
-  const actualArray = ArrayFrom(FunctionPrototypeCall(SafeSet.prototype[SymbolIterator], actual));
+  // Create a map for faster lookups
+  const actualMap = new SafeMap();
+  const actualIterator = FunctionPrototypeCall(SafeSet.prototype[SymbolIterator], actual);
   const expectedIterator = FunctionPrototypeCall(SafeSet.prototype[SymbolIterator], expected);
-  const usedIndices = new SafeSet();
 
-  expectedIteration: for (const expectedItem of expectedIterator) {
-    for (let actualIdx = 0; actualIdx < actualArray.length; actualIdx++) {
-      if (!usedIndices.has(actualIdx) && isDeepStrictEqual(actualArray[actualIdx], expectedItem)) {
-        usedIndices.add(actualIdx);
-        continue expectedIteration;
+  for (const actualItem of actualIterator) {
+    actualMap.set(actualItem, true);
+  }
+
+  for (const expectedItem of expectedIterator) {
+    let foundMatch = false;
+
+    // Check for primitives first to avoid useless loops
+    if (isPrimitive(expectedItem)) {
+      if (actualMap.has(expectedItem)) {
+        actualMap.delete(expectedItem);
+        foundMatch = true;
+      }
+    } else {
+      // Check for non-primitives
+      for (const { 0: actualItem } of actualMap) {
+        if (isDeepStrictEqual(actualItem, expectedItem)) {
+          actualMap.delete(actualItem);
+          foundMatch = true;
+          break;
+        }
       }
     }
-    return false;
+
+    if (!foundMatch) {
+      return false;
+    }
   }
 
   return true;
@@ -518,13 +536,11 @@ function partiallyCompareArrays(actual, expected, comparedObjects) {
 
   // Create a map to count occurrences of each element in the expected array
   const expectedCounts = new SafeMap();
-  const safeExpected = new SafeArrayIterator(expected);
 
-  for (const expectedItem of safeExpected) {
-    // Check if the item is a zero or a -0, as these need to be handled separately
+  for (const expectedItem of new SafeArrayIterator(expected)) {
     if (expectedItem === 0) {
       const zeroKey = getZeroKey(expectedItem);
-      expectedCounts.set(zeroKey, (expectedCounts.get(zeroKey)?.count || 0) + 1);
+      expectedCounts.set(zeroKey, (expectedCounts.get(zeroKey) ?? 0) + 1);
     } else {
       let found = false;
       for (const { 0: key, 1: count } of expectedCounts) {
@@ -540,10 +556,7 @@ function partiallyCompareArrays(actual, expected, comparedObjects) {
     }
   }
 
-  const safeActual = new SafeArrayIterator(actual);
-
-  for (const actualItem of safeActual) {
-    // Check if the item is a zero or a -0, as these need to be handled separately
+  for (const actualItem of new SafeArrayIterator(actual)) {
     if (actualItem === 0) {
       const zeroKey = getZeroKey(actualItem);
 
@@ -723,6 +736,10 @@ function compareExceptionKey(actual, expected, key, message, keys, fn) {
   }
 }
 
+function isPrimitive(value) {
+  return typeof value !== 'object' || value === null;
+}
+
 function expectedException(actual, expected, message, fn) {
   let generatedMessage = false;
   let throwError = false;
@@ -741,7 +758,7 @@ function expectedException(actual, expected, message, fn) {
       }
       throwError = true;
       // Handle primitives properly.
-    } else if (typeof actual !== 'object' || actual === null) {
+    } else if (isPrimitive(actual)) {
       const err = new AssertionError({
         actual,
         expected,