feat(types): add MagicRegExpMatchArray utility type (#12)

Author: XLor

src/index.ts

@@ -15,16 +15,29 @@ export const createRegExp = <Value extends string, NamedGroups extends string =
 export * from './core/flags'
 export * from './core/inputs'
 
+type ExtractNamedGroups<T extends MagicRegExp<string, string>> = T extends MagicRegExp<
+  string,
+  infer V
+>
+  ? V
+  : never
+
+export type MagicRegExpMatchArray<T extends MagicRegExp<string, string>> = Omit<
+  RegExpMatchArray,
+  'groups'
+> & {
+  groups: Record<ExtractNamedGroups<T>, string | undefined>
+}
+
 // Add additional overload to global String object types to allow for typed capturing groups
 declare global {
   interface String {
-    match<T extends string>(
-      regexp: MagicRegExp<any, T>
-    ): (Omit<RegExpMatchArray, 'groups'> & { groups: Record<T, string | undefined> }) | null
-    matchAll<T extends string>(
-      regexp: MagicRegExp<any, T>
-    ): IterableIterator<
-      Omit<RegExpMatchArray, 'groups'> & { groups: Record<T, string | undefined> }
-    >
+    match<T extends string, RegExp extends MagicRegExp<any, T>>(
+      regexp: RegExp
+    ): MagicRegExpMatchArray<RegExp> | null
+
+    matchAll<T extends string, RegExp extends MagicRegExp<any, T>>(
+      regexp: RegExp
+    ): IterableIterator<MagicRegExpMatchArray<RegExp>>
   }
 }

test/index.test.ts

@@ -1,7 +1,7 @@
 import { expect, it, describe } from 'vitest'
 import { expectTypeOf } from 'expect-type'
 
-import { anyOf, char, createRegExp, exactly, global, digit } from '../src'
+import { anyOf, char, createRegExp, exactly, global, digit, MagicRegExpMatchArray } from '../src'
 import { createInput } from '../src/core/internal'
 
 describe('magic-regexp', () => {
@@ -71,6 +71,11 @@ describe('inputs', () => {
         "test2": "baz",
       }
     `)
+
+    const regexp = createRegExp(pattern)
+    expectTypeOf('fobazzer'.match(regexp)).toMatchTypeOf<MagicRegExpMatchArray<
+      typeof regexp
+    > | null>()
     expectTypeOf('fobazzer'.match(createRegExp(pattern))?.groups).toMatchTypeOf<
       Record<'test' | 'test2', string | undefined> | undefined
     >()