is-shallow-equal: Convert to ESM (#26833)

* is-shallow-equal: Convert to ESM

* is-shallow-equal: Fix test import for ci

* Fix react-native module resolution

* Clean up unnecessary code.

* Update files entry

* Update benchmark instructions and CHANGELOG

packages/is-shallow-equal/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Breaking Change
+
+- Re-write using ES Modules causing CJS default import to change from `require('@wordpress/is-shallow-equal)` to `require('@wordpress/is-shallow-equal).default`. ([#26833](https://github.com/WordPress/gutenberg/pull/26833))
+
 ## 2.0.0 (2020-04-15)
 
 ### Breaking Change

packages/is-shallow-equal/README.md

@@ -122,10 +122,10 @@ The following results were produced under Node v10.15.3 (LTS) on a MacBook Pro (
 You can run the benchmarks yourselves by cloning the repository, installing dependencies, and running the `benchmark/index.js` script:
 
 ```
-git clone https://github.com/WordPress/packages.git
-cd packages/packages/is-shallow-equal
+git clone https://github.com/WordPress/gutenberg.git
 npm install
-node benchmark
+npm run build:packages
+node ./packages/is-shallow-equal/benchmark
 ```
 
 <br/><br/><p align="center"><img src="https://s.w.org/style/images/codeispoetry.png?1" alt="Code is Poetry." /></p>

packages/is-shallow-equal/benchmark/index.js

@@ -43,7 +43,7 @@ Promise.all( [
 				require( '..' ).isShallowEqualObjects,
 				require( '..' ).isShallowEqualArrays,
 			],
-			[ '@wordpress/is-shallow-equal', require( '..' ) ],
+			[ '@wordpress/is-shallow-equal', require( '..' ).default ],
 			[ 'shallowequal', shallowequal ],
 			[
 				'shallow-equal (type specific)',

packages/is-shallow-equal/package.json

@@ -21,11 +21,15 @@
 		"url": "https://github.com/WordPress/gutenberg/issues"
 	},
 	"files": [
-		"lib",
+		"build",
+		"build-module",
 		"build-types",
+		"src",
 		"*.md"
 	],
-	"main": "lib/index.js",
+	"main": "build/index.js",
+	"module": "build-module/index.js",
+	"react-native": "src/index",
 	"types": "build-types",
 	"sideEffects": false,
 	"dependencies": {

packages/is-shallow-equal/lib/arrays.js → packages/is-shallow-equal/src/arrays.js

@@ -1,5 +1,3 @@
-'use strict';
-
 /**
  * Returns true if the two arrays are shallow equal, or false otherwise.
  *
@@ -8,9 +6,7 @@
  *
  * @return {boolean} Whether the two arrays are shallow equal.
  */
-function isShallowEqualArrays( a, b ) {
-	var i;
-
+export default function isShallowEqualArrays( a, b ) {
 	if ( a === b ) {
 		return true;
 	}
@@ -19,13 +15,11 @@ function isShallowEqualArrays( a, b ) {
 		return false;
 	}
 
-	for ( i = 0; i < a.length; i++ ) {
+	for ( let i = 0, len = a.length; i < len; i++ ) {
 		if ( a[ i ] !== b[ i ] ) {
 			return false;
 		}
 	}
 
 	return true;
 }
-
-module.exports = isShallowEqualArrays;

packages/is-shallow-equal/lib/index.js → packages/is-shallow-equal/src/index.js

@@ -1,12 +1,11 @@
-'use strict';
-
 /**
- * Internal dependencies;
+ * Internal dependencies
  */
-var isShallowEqualObjects = require( './objects' );
-var isShallowEqualArrays = require( './arrays' );
+import isShallowEqualObjects from './objects';
+import isShallowEqualArrays from './arrays';
 
-var isArray = Array.isArray;
+export { default as isShallowEqualObjects } from './objects';
+export { default as isShallowEqualArrays } from './arrays';
 
 /**
  * @typedef {Record<string, any>} ComparableObject
@@ -21,18 +20,14 @@ var isArray = Array.isArray;
  *
  * @return {boolean} Whether the two values are shallow equal.
  */
-function isShallowEqual( a, b ) {
+export default function isShallowEqual( a, b ) {
 	if ( a && b ) {
 		if ( a.constructor === Object && b.constructor === Object ) {
 			return isShallowEqualObjects( a, b );
-		} else if ( isArray( a ) && isArray( b ) ) {
+		} else if ( Array.isArray( a ) && Array.isArray( b ) ) {
 			return isShallowEqualArrays( a, b );
 		}
 	}
 
 	return a === b;
 }
-
-module.exports = isShallowEqual;
-module.exports.isShallowEqualObjects = isShallowEqualObjects;
-module.exports.isShallowEqualArrays = isShallowEqualArrays;

packages/is-shallow-equal/lib/objects.js → packages/is-shallow-equal/src/objects.js

@@ -1,7 +1,3 @@
-'use strict';
-
-var keys = Object.keys;
-
 /**
  * Returns true if the two objects are shallow equal, or false otherwise.
  *
@@ -10,25 +6,23 @@ var keys = Object.keys;
  *
  * @return {boolean} Whether the two objects are shallow equal.
  */
-function isShallowEqualObjects( a, b ) {
-	var aKeys, bKeys, i, key, aValue;
-
+export default function isShallowEqualObjects( a, b ) {
 	if ( a === b ) {
 		return true;
 	}
 
-	aKeys = keys( a );
-	bKeys = keys( b );
+	const aKeys = Object.keys( a );
+	const bKeys = Object.keys( b );
 
 	if ( aKeys.length !== bKeys.length ) {
 		return false;
 	}
 
-	i = 0;
+	let i = 0;
 
 	while ( i < aKeys.length ) {
-		key = aKeys[ i ];
-		aValue = a[ key ];
+		const key = aKeys[ i ];
+		const aValue = a[ key ];
 
 		if (
 			// In iterating only the keys of the first object after verifying
@@ -47,5 +41,3 @@ function isShallowEqualObjects( a, b ) {
 
 	return true;
 }
-
-module.exports = isShallowEqualObjects;

packages/is-shallow-equal/test/index.js

@@ -4,7 +4,7 @@
 import isShallowEqual, {
 	isShallowEqualArrays,
 	isShallowEqualObjects,
-} from '..';
+} from '../src';
 
 describe( 'isShallowEqual', () => {
 	it( 'returns false if of different types', () => {

packages/is-shallow-equal/tsconfig.json

@@ -1,8 +1,8 @@
 {
 	"extends": "../../tsconfig.base.json",
 	"compilerOptions": {
-		"rootDir": "lib",
+		"rootDir": "src",
 		"declarationDir": "build-types"
 	},
-	"include": [ "lib/**/*" ]
+	"include": [ "src/**/*" ]
 }