feat: add array.prototype.flat, array.prototype.flatMap

codemods/array.prototype.flat/index.js

@@ -0,0 +1,48 @@
+import jscodeshift from 'jscodeshift';
+import { removeImport } from '../shared.js';
+
+/**
+ * @typedef {import('../../types.js').Codemod} Codemod
+ * @typedef {import('../../types.js').CodemodOptions} CodemodOptions
+ */
+
+/**
+ * @param {CodemodOptions} [options]
+ * @returns {Codemod}
+ */
+export default function (options) {
+	return {
+		name: 'array.prototype.flat',
+		transform: ({ file }) => {
+			const j = jscodeshift;
+			const root = j(file.source);
+			let dirtyFlag = false;
+
+			const { identifier } = removeImport('array.prototype.flat', root, j);
+
+			root
+				.find(j.CallExpression, {
+					callee: {
+						type: 'Identifier',
+						name: identifier,
+					},
+				})
+				.forEach((path) => {
+					const args = path.value.arguments;
+					if (args.length === 2) {
+						const [array, callback] = args;
+
+						const newExpression = j.callExpression(
+							//@ts-ignore
+							j.memberExpression(array, j.identifier('flat')),
+							[callback],
+						);
+						j(path).replaceWith(newExpression);
+						dirtyFlag = true;
+					}
+				});
+
+			return dirtyFlag ? root.toSource(options) : file.source;
+		},
+	};
+}

codemods/array.prototype.flatMap/index.js

@@ -0,0 +1,48 @@
+import jscodeshift from 'jscodeshift';
+import { removeImport } from '../shared.js';
+
+/**
+ * @typedef {import('../../types.js').Codemod} Codemod
+ * @typedef {import('../../types.js').CodemodOptions} CodemodOptions
+ */
+
+/**
+ * @param {CodemodOptions} [options]
+ * @returns {Codemod}
+ */
+export default function (options) {
+	return {
+		name: 'array.prototype.flatMap',
+		transform: ({ file }) => {
+			const j = jscodeshift;
+			const root = j(file.source);
+			let dirtyFlag = false;
+
+			const { identifier } = removeImport('array.prototype.flatMap', root, j);
+
+			root
+				.find(j.CallExpression, {
+					callee: {
+						type: 'Identifier',
+						name: identifier,
+					},
+				})
+				.forEach((path) => {
+					const args = path.value.arguments;
+					if (args.length === 2) {
+						const [array, callback] = args;
+
+						const newExpression = j.callExpression(
+							//@ts-ignore
+							j.memberExpression(array, j.identifier('flatMap')),
+							[callback],
+						);
+						j(path).replaceWith(newExpression);
+						dirtyFlag = true;
+					}
+				});
+
+			return dirtyFlag ? root.toSource(options) : file.source;
+		},
+	};
+}

codemods/index.js

@@ -64,6 +64,10 @@ import arrayPrototypeFind from './array.prototype.find/index.js';
 
 import arrayPrototypeFindIndex from './array.prototype.findIndex/index.js';
 
+import arrayPrototypeFlat from './array.prototype.flat/index.js';
+
+import arrayPrototypeFlatMap from './array.prototype.flatMap/index.js';
+
 export const codemods = {
     'is-whitespace': isWhitespace,
     'is-array-buffer': isArrayBuffer,
@@ -98,4 +102,6 @@ export const codemods = {
     'array.prototype.entries': arrayPrototypeEntries,
     'array.prototype.find': arrayPrototypeFind,
     'array.prototype.findIndex': arrayPrototypeFindIndex,
+    'array.prototype.flat': arrayPrototypeFlat,
+    'array.prototype.flatMap': arrayPrototypeFlatMap,
 };

test/fixtures/array.prototype.flat/case-1/after.js

@@ -0,0 +1,14 @@
+var assert = require('assert');
+
+assert.deepEqual(
+  [1, 2, 3].flat(function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  [1, 2, 3].flat(function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flat/case-1/before.js

@@ -0,0 +1,15 @@
+var flat = require('array.prototype.flat');
+var assert = require('assert');
+
+assert.deepEqual(
+  flat([1, 2, 3], function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  flat([1, 2, 3], function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flat/case-1/result.js

@@ -0,0 +1,14 @@
+var assert = require('assert');
+
+assert.deepEqual(
+  [1, 2, 3].flat(function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  [1, 2, 3].flat(function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flat/case-2/after.js

@@ -0,0 +1,14 @@
+var assert = require('assert');
+
+assert.deepEqual(
+  [1, 2, 3].flat(function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  [1, 2, 3].flat(function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flat/case-2/before.js

@@ -0,0 +1,15 @@
+import flat from 'array.prototype.flat';
+var assert = require('assert');
+
+assert.deepEqual(
+  flat([1, 2, 3], function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  flat([1, 2, 3], function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flat/case-2/result.js

@@ -0,0 +1,14 @@
+var assert = require('assert');
+
+assert.deepEqual(
+  [1, 2, 3].flat(function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  [1, 2, 3].flat(function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flat/case-3/after.js

@@ -0,0 +1,14 @@
+var assert = require('assert');
+
+assert.deepEqual(
+  [1, 2, 3].flat(function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  [1, 2, 3].flat(function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flat/case-3/before.js

@@ -0,0 +1,15 @@
+var banana = require('array.prototype.flat');
+var assert = require('assert');
+
+assert.deepEqual(
+  banana([1, 2, 3], function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  banana([1, 2, 3], function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flat/case-3/result.js

@@ -0,0 +1,14 @@
+var assert = require('assert');
+
+assert.deepEqual(
+  [1, 2, 3].flat(function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  [1, 2, 3].flat(function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flat/case-4/after.js

@@ -0,0 +1,14 @@
+var assert = require('assert');
+
+assert.deepEqual(
+  [1, 2, 3].flat(function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  [1, 2, 3].flat(function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flat/case-4/before.js

@@ -0,0 +1,15 @@
+import banana from 'array.prototype.flat';
+var assert = require('assert');
+
+assert.deepEqual(
+  banana([1, 2, 3], function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  banana([1, 2, 3], function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flat/case-4/result.js

@@ -0,0 +1,14 @@
+var assert = require('assert');
+
+assert.deepEqual(
+  [1, 2, 3].flat(function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  [1, 2, 3].flat(function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flatMap/case-1/after.js

@@ -0,0 +1,14 @@
+var assert = require('assert');
+
+assert.deepEqual(
+  [1, 2, 3].flatMap(function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  [1, 2, 3].flatMap(function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flatMap/case-1/before.js

@@ -0,0 +1,15 @@
+var flatMap = require('array.prototype.flatMap');
+var assert = require('assert');
+
+assert.deepEqual(
+  flatMap([1, 2, 3], function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  flatMap([1, 2, 3], function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flatMap/case-1/result.js

@@ -0,0 +1,14 @@
+var assert = require('assert');
+
+assert.deepEqual(
+  [1, 2, 3].flatMap(function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  [1, 2, 3].flatMap(function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flatMap/case-2/after.js

@@ -0,0 +1,14 @@
+var assert = require('assert');
+
+assert.deepEqual(
+  [1, 2, 3].flatMap(function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  [1, 2, 3].flatMap(function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flatMap/case-2/before.js

@@ -0,0 +1,15 @@
+import flatMap from 'array.prototype.flatMap';
+var assert = require('assert');
+
+assert.deepEqual(
+  flatMap([1, 2, 3], function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  flatMap([1, 2, 3], function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);

test/fixtures/array.prototype.flatMap/case-2/result.js

@@ -0,0 +1,14 @@
+var assert = require('assert');
+
+assert.deepEqual(
+  [1, 2, 3].flatMap(function (x) {
+    return x >= 2;
+  }),
+  [2, 3],
+);
+assert.deepEqual(
+  [1, 2, 3].flatMap(function (x) {
+    return x <= 2;
+  }),
+  [1, 2],
+);