improvement(utils): add escapeRegExp and compareStrings to @sim/utils/string

Author: waleedlatif1

packages/utils/src/string.test.ts

@@ -3,6 +3,8 @@
  */
 import { describe, expect, it } from 'vitest'
 import {
+  compareStrings,
+  escapeRegExp,
   forEachSearchOccurrence,
   formatQuotedNameList,
   isVersionedType,
@@ -246,3 +248,41 @@ describe('forEachSearchOccurrence', () => {
     expect(spans('\u0130xyz target', 'target')).toEqual(['target'])
   })
 })
+
+describe('escapeRegExp', () => {
+  it('escapes every regex metacharacter', () => {
+    const metacharacters = `.*+?^$${'{}'}()|[]\\`
+    expect(escapeRegExp(metacharacters)).toBe('\\.\\*\\+\\?\\^\\$\\{\\}\\(\\)\\|\\[\\]\\\\')
+  })
+
+  it('leaves ordinary text untouched', () => {
+    expect(escapeRegExp('plain text 42')).toBe('plain text 42')
+  })
+
+  it('matches the literal value once interpolated', () => {
+    const pattern = new RegExp(escapeRegExp('a.b'))
+    expect(pattern.test('a.b')).toBe(true)
+    expect(pattern.test('axb')).toBe(false)
+  })
+
+  it('escapes every occurrence, not just the first', () => {
+    expect(escapeRegExp('a.b.c')).toBe('a\\.b\\.c')
+  })
+})
+
+describe('compareStrings', () => {
+  it('orders by code unit', () => {
+    expect(compareStrings('a', 'b')).toBe(-1)
+    expect(compareStrings('b', 'a')).toBe(1)
+    expect(compareStrings('a', 'a')).toBe(0)
+  })
+
+  it('sorts uppercase before lowercase, unlike localeCompare', () => {
+    expect(compareStrings('Z', 'a')).toBe(-1)
+    expect(['a', 'Z'].sort(compareStrings)).toEqual(['Z', 'a'])
+  })
+
+  it('orders digit-led keys lexically, not numerically', () => {
+    expect(['2', '10'].sort(compareStrings)).toEqual(['10', '2'])
+  })
+})

packages/utils/src/string.ts

@@ -337,3 +337,26 @@ function identityStarts(length: number): number[] {
   for (let index = 0; index <= length; index += 1) starts[index] = index
   return starts
 }
+
+/**
+ * Escapes every regex metacharacter in `value` so it matches only itself when
+ * interpolated into a `RegExp`.
+ *
+ * @example
+ * new RegExp(escapeRegExp('a.b')) // matches the literal 'a.b', not 'axb'
+ */
+export function escapeRegExp(value: string): string {
+  return value.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')
+}
+
+/**
+ * Compares two strings by code unit, the ordering `Array.prototype.sort` applies
+ * by default. Deliberately not `localeCompare`: ordering that feeds a hash, a
+ * fingerprint, or a value compared across processes must not vary with the
+ * host's locale.
+ */
+export function compareStrings(left: string, right: string): number {
+  if (left < right) return -1
+  if (left > right) return 1
+  return 0
+}