feat(internal): escapeRegExp

Signed-off-by: Lexus Drumgold <unicornware@flexdevelopment.llc>

Author: unicornware

src/internal/__tests__/escape-reg-exp.spec.ts

@@ -0,0 +1,18 @@
+/**
+ * @file Unit Tests - escapeRegExp
+ * @module mlly/internal/tests/unit/escapeRegExp
+ */
+
+import testSubject from '../escape-reg-exp'
+
+describe('unit:internal/escapeRegExp', () => {
+  it('should escape special characters', () => {
+    // Arrange
+    const pattern: string = '\\ ^ $ * + ? . ( ) | { } [ ] -'
+    const expected: string =
+      '\\\\ \\^ \\$ \\* \\+ \\? \\. \\( \\) \\| \\{ \\} \\[ \\] \\x2d'
+
+    // Act + Expect
+    expect(testSubject(pattern)).to.equal(expected)
+  })
+})

src/internal/escape-reg-exp.ts

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+/**
+ * @file Internal - escapeRegExp
+ * @module mlly/internal/escapeRegExp
+ */
+
+import type { NodeError } from '@flex-development/errnode'
+import validateString from './validate-string'
+
+/**
+ * Escapes special characters in the given regex `pattern`.
+ *
+ * A backslash escape (`\\`) is used when valid. A `\x2d` escape is used when
+ * the former would be disallowed by stricter Unicode pattern grammar.
+ *
+ * @param {string} pattern - Regex pattern to escape
+ * @return {string} `pattern` with special characters escaped
+ * @throws {NodeError<TypeError>} If `pattern` is not a string
+ */
+const escapeRegExp = (pattern: string): string => {
+  validateString(pattern, 'pattern')
+  return pattern.replace(/[$()*+.?[\\\]^{|}]/g, '\\$&').replace(/-/g, '\\x2d')
+}
+
+export default escapeRegExp