feat: add isEqualCaseInsensitive() to @metamask/controller-utils (#4811)

## Explanation

Moves `isEqualCaseInsensitive()` from assets-controllers into
controller-utils because it will be used elsewhere downstream

## References

Upstream: None. This is the start.
Downstream: #4812

## Changelog

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### `@metamask/controller-utils`

- **ADDED**: Export `isEqualCaseInsensitive()` helper which performs
case insensitive comparison against two strings and returns true if they
are equivalent.

## Checklist

- [X] I've updated the test suite for new or updated code as appropriate
- [X] I've updated documentation (JSDoc, Markdown, etc.) for new or
updated code as appropriate
- [X] I've highlighted breaking changes using the "BREAKING" category
above as appropriate
- [X] I've prepared draft pull requests for clients and consumer
packages to resolve any breaking changes

---------

Co-authored-by: Mark Stacey <markjstacey@gmail.com>
Co-authored-by: Alex Donesky <adonesky@gmail.com>

Author: 3 people

packages/assets-controllers/src/TokenDetectionController.ts

@@ -14,6 +14,7 @@ import {
   ChainId,
   ERC20,
   safelyExecute,
+  isEqualCaseInsensitive,
 } from '@metamask/controller-utils';
 import type {
   KeyringControllerGetStateAction,
@@ -54,26 +55,6 @@ import type {
 
 const DEFAULT_INTERVAL = 180000;
 
-/**
- * Compare 2 given strings and return boolean
- * eg: "foo" and "FOO" => true
- * eg: "foo" and "bar" => false
- * eg: "foo" and 123 => false
- *
- * @param value1 - first string to compare
- * @param value2 - first string to compare
- * @returns true if 2 strings are identical when they are lowercase
- */
-export function isEqualCaseInsensitive(
-  value1: string,
-  value2: string,
-): boolean {
-  if (typeof value1 !== 'string' || typeof value2 !== 'string') {
-    return false;
-  }
-  return value1.toLowerCase() === value2.toLowerCase();
-}
-
 type LegacyToken = {
   name: string;
   logo: `${string}.svg`;

packages/controller-utils/src/index.ts

@@ -27,6 +27,7 @@ export {
   toChecksumHexAddress,
   toHex,
   weiHexToGweiDec,
+  isEqualCaseInsensitive,
 } from './util';
 export * from './types';
 export * from './siwe';

packages/controller-utils/src/util.test.ts

@@ -611,3 +611,33 @@ describe('util', () => {
     });
   });
 });
+
+describe('isEqualCaseInsensitive', () => {
+  it('returns false for non-string values', () => {
+    // @ts-expect-error Invalid type for testing purposes
+    expect(util.isEqualCaseInsensitive(null, null)).toBe(false);
+    // @ts-expect-error Invalid type for testing purposes
+    expect(util.isEqualCaseInsensitive(5, 5)).toBe(false);
+    // @ts-expect-error Invalid type for testing purposes
+    expect(util.isEqualCaseInsensitive(null, 'test')).toBe(false);
+    // @ts-expect-error Invalid type for testing purposes
+    expect(util.isEqualCaseInsensitive('test', null)).toBe(false);
+    // @ts-expect-error Invalid type for testing purposes
+    expect(util.isEqualCaseInsensitive(5, 'test')).toBe(false);
+    // @ts-expect-error Invalid type for testing purposes
+    expect(util.isEqualCaseInsensitive('test', 5)).toBe(false);
+  });
+
+  it('returns false for strings that are not equal', () => {
+    expect(util.isEqualCaseInsensitive('test', 'test1')).toBe(false);
+    expect(util.isEqualCaseInsensitive('test1', 'test')).toBe(false);
+  });
+
+  it('returns true for strings that are equal', () => {
+    expect(util.isEqualCaseInsensitive('test', 'TEST')).toBe(true);
+    expect(util.isEqualCaseInsensitive('test', 'test')).toBe(true);
+    expect(util.isEqualCaseInsensitive('TEST', 'TEST')).toBe(true);
+    expect(util.isEqualCaseInsensitive('test', 'Test')).toBe(true);
+    expect(util.isEqualCaseInsensitive('Test', 'test')).toBe(true);
+  });
+});

packages/controller-utils/src/util.ts

@@ -619,3 +619,20 @@ function logOrRethrowError(error: unknown, codesToCatch: number[] = []) {
     throw error;
   }
 }
+
+/**
+ * Checks if two strings are equal, ignoring case.
+ *
+ * @param value1 - The first string to compare.
+ * @param value2 - The second string to compare.
+ * @returns `true` if the strings are equal, ignoring case; otherwise, `false`.
+ */
+export function isEqualCaseInsensitive(
+  value1: string,
+  value2: string,
+): boolean {
+  if (typeof value1 !== 'string' || typeof value2 !== 'string') {
+    return false;
+  }
+  return value1.toLowerCase() === value2.toLowerCase();
+}