shallowEqual.js — react Source File

Architecture documentation for shallowEqual.js, a javascript file in the react codebase. 3 imports, 0 dependents.

File javascript BabelCompiler Optimization 3 imports 1 functions

Entity Profile

BabelCompiler→ Optimization→ shallowEqual.js — react Source File

Dependency Diagram

graph LR
  453d8884_196c_9b47_f492_31e5c07005e7["shallowEqual.js"]
  6e14608c_da3e_3b32_c806_aa3aab42a0c9["objectIs.js"]
  453d8884_196c_9b47_f492_31e5c07005e7 --> 6e14608c_da3e_3b32_c806_aa3aab42a0c9
  dab343e7_d491_ab84_5374_66898c315624["is"]
  453d8884_196c_9b47_f492_31e5c07005e7 --> dab343e7_d491_ab84_5374_66898c315624
  89ac798a_a938_334b_3064_cf5384f9cb5c["hasOwnProperty.js"]
  453d8884_196c_9b47_f492_31e5c07005e7 --> 89ac798a_a938_334b_3064_cf5384f9cb5c
  style 453d8884_196c_9b47_f492_31e5c07005e7 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

/**
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 */

import is from './objectIs';
import hasOwnProperty from './hasOwnProperty';

/**
 * Performs equality by iterating through keys on an object and returning false
 * when any key has values which are not strictly equal between the arguments.
 * Returns true when the values of all keys are strictly equal.
 */
function shallowEqual(objA: mixed, objB: mixed): boolean {
  if (is(objA, objB)) {
    return true;
  }

  if (
    typeof objA !== 'object' ||
    objA === null ||
    typeof objB !== 'object' ||
    objB === null
  ) {
    return false;
  }

  const keysA = Object.keys(objA);
  const keysB = Object.keys(objB);

  if (keysA.length !== keysB.length) {
    return false;
  }

  // Test for A's keys different from B.
  for (let i = 0; i < keysA.length; i++) {
    const currentKey = keysA[i];
    if (
      !hasOwnProperty.call(objB, currentKey) ||
      // $FlowFixMe[incompatible-use] lost refinement of `objB`
      !is(objA[currentKey], objB[currentKey])
    ) {
      return false;
    }
  }

  return true;
}

export default shallowEqual;