feat(pluginutils): add wordRegex

packages/pluginutils/README.md

@@ -240,6 +240,22 @@ exactRegex(['foo', 'bar']); // /^(?:foo|bar)$/
 exactRegex('foo(bar)', 'i'); // /^foo\(bar\)$/i
 ```
 
+### wordRegex
+
+Constructs a RegExp that matches the specified string with word boundaries. This is useful when matching a complete word-like token, such as `node_modules` but not `node_modulesa`.
+
+Parameters: `(str: String, flags?: String)`<br>
+Returns: `RegExp`
+
+#### Usage
+
+```js
+import { wordRegex } from '@rollup/pluginutils';
+
+wordRegex('node_modules'); // /\bnode_modules\b/
+wordRegex('foo.bar', 'i'); // /\bfoo\.bar\b/i
+```
+
 ### makeLegalIdentifier
 
 Constructs a bundle-safe identifier from a `String`.

packages/pluginutils/src/filterUtils.ts

@@ -10,7 +10,11 @@ export function suffixRegex(str: string | string[], flags?: string): RegExp {
   return new RegExp(`${combineMultipleStrings(str)}$`, flags);
 }
 
-const escapeRegexRE = /[-/\\^$*+?.()|[\]{}]/g;
+export function wordRegex(str: string, flags?: string): RegExp {
+  return new RegExp(`\\b${escapeRegex(str)}\\b`, flags);
+}
+
+const escapeRegexRE = /[/\\^$*+?.()|[\]{}]/g;
 function escapeRegex(str: string): string {
   return str.replace(escapeRegexRE, '\\$&');
 }

packages/pluginutils/src/index.ts

@@ -5,7 +5,7 @@ import dataToEsm from './dataToEsm';
 import extractAssignedNames from './extractAssignedNames';
 import makeLegalIdentifier from './makeLegalIdentifier';
 import normalizePath from './normalizePath';
-import { exactRegex, prefixRegex, suffixRegex } from './filterUtils';
+import { exactRegex, prefixRegex, suffixRegex, wordRegex } from './filterUtils';
 
 export {
   addExtension,
@@ -17,7 +17,8 @@ export {
   makeLegalIdentifier,
   normalizePath,
   prefixRegex,
-  suffixRegex
+  suffixRegex,
+  wordRegex
 };
 
 // TODO: remove this in next major
@@ -31,5 +32,6 @@ export default {
   makeLegalIdentifier,
   normalizePath,
   prefixRegex,
-  suffixRegex
+  suffixRegex,
+  wordRegex
 };

packages/pluginutils/test/filterUtils.ts

@@ -1,4 +1,4 @@
-import { exactRegex, prefixRegex, suffixRegex } from '../';
+import { exactRegex, prefixRegex, suffixRegex, wordRegex } from '../';
 
 test('exactRegex supports without flag parameter', () => {
   expect(exactRegex('foo').toString()).toBe('/^foo$/');
@@ -71,3 +71,30 @@ test('suffixRegex escapes special characters for Regex', () => {
 test('suffixRegex escapes special characters with multiple string for Regex', () => {
   expect(suffixRegex(['foo(bar)', 'baz(qux)']).toString()).toBe('/(?:foo\\(bar\\)|baz\\(qux\\))$/');
 });
+
+test('wordRegex matches complete word-like tokens', () => {
+  const regex = wordRegex('node_modules');
+
+  expect(regex.toString()).toBe('/\\bnode_modules\\b/');
+  expect(regex.test('node_modules')).toBe(true);
+  expect(regex.test('/node_modules/')).toBe(true);
+  expect(regex.test('foo/node_modules/bar')).toBe(true);
+  expect(regex.test('node_modulesa')).toBe(false);
+  expect(regex.test('anode_modules')).toBe(false);
+});
+
+test('wordRegex supports flags and escapes special characters', () => {
+  const regex = wordRegex('foo.bar', 'i');
+
+  expect(regex.toString()).toBe('/\\bfoo\\.bar\\b/i');
+  expect(regex.test('FOO.BAR')).toBe(true);
+  expect(regex.test('foo.barx')).toBe(false);
+});
+
+test('wordRegex supports hyphens with the Unicode flag', () => {
+  const regex = wordRegex('foo-bar', 'u');
+
+  expect(regex.toString()).toBe('/\\bfoo-bar\\b/u');
+  expect(regex.test('foo-bar')).toBe(true);
+  expect(regex.test('foo-barx')).toBe(false);
+});

packages/pluginutils/types/index.d.ts

@@ -99,6 +99,13 @@ export function prefixRegex(str: string | string[], flags?: string): RegExp;
  */
 export function suffixRegex(str: string | string[], flags?: string): RegExp;
 
+/**
+ * Constructs a RegExp that matches the specified string with word boundaries.
+ * @param str the string to match.
+ * @param flags flags for the RegExp.
+ */
+export function wordRegex(str: string, flags?: string): RegExp;
+
 export type AddExtension = typeof addExtension;
 export type AttachScopes = typeof attachScopes;
 export type CreateFilter = typeof createFilter;
@@ -109,6 +116,7 @@ export type NormalizePath = typeof normalizePath;
 export type DataToEsm = typeof dataToEsm;
 export type PrefixRegex = typeof prefixRegex;
 export type SuffixRegex = typeof suffixRegex;
+export type WordRegex = typeof wordRegex;
 
 declare const defaultExport: {
   addExtension: AddExtension;
@@ -121,5 +129,6 @@ declare const defaultExport: {
   normalizePath: NormalizePath;
   prefixRegex: PrefixRegex;
   suffixRegex: SuffixRegex;
+  wordRegex: WordRegex;
 };
 export default defaultExport;