Add trim functionality with tests and update package exports

package.json

@@ -96,6 +96,11 @@
       "types": "./dist/storage.d.ts",
       "import": "./dist/storage.mjs",
       "default": "./dist/storage.js"
+    },
+    "./trim": {
+      "types": "./dist/trim.d.ts",
+      "import": "./dist/trim.mjs",
+      "default": "./dist/trim.js"
     }
   },
   "keywords": [],

src/entrypoints/recommended.d.ts

@@ -8,3 +8,4 @@
 /// <reference path="map-has.d.ts" />
 /// <reference path="array-index-of.d.ts" />
 /// <reference path="promise-catch.d.ts" />
+/// <reference path="trim.d.ts" />

src/entrypoints/trim.d.ts

@@ -0,0 +1,17 @@
+type Whitespace = " " | "\n" | "\t";
+
+type TrimLeft<S extends string> = S extends `${Whitespace}${infer Rest}`
+  ? TrimLeft<Rest>
+  : S;
+
+type TrimRight<S extends string> = S extends `${infer Rest}${Whitespace}`
+  ? TrimRight<Rest>
+  : S;
+
+interface String {
+  trim<S extends string>(this: S): TrimLeft<TrimRight<S>>;
+  trimRight<S extends string>(this: S): TrimRight<S>;
+  trimStart<S extends string>(this: S): TrimLeft<S>;
+  trimLeft<S extends string>(this: S): TrimLeft<S>;
+  trimEnd<S extends string>(this: S): TrimRight<S>;
+}

src/tests/trim.ts

@@ -0,0 +1,70 @@
+import { doNotExecute, Equal, Expect } from "./utils";
+
+doNotExecute(() => {
+  const str = "  hello  " as const;
+
+  // trim tests
+  const trimmed = str.trim();
+  type trimTest = [Expect<Equal<typeof trimmed, "hello">>];
+
+  // trimStart/trimLeft tests
+  const trimmedStart = str.trimStart();
+  type trimStartTest = Expect<Equal<typeof trimmedStart, "hello  ">>;
+
+  const trimmedLeft = str.trimLeft();
+  type trimLeftTest = Expect<Equal<typeof trimmedLeft, "hello  ">>;
+
+  // trimEnd/trimRight tests
+  const trimmedEnd = str.trimEnd();
+  type trimEndTest = Expect<Equal<typeof trimmedEnd, "  hello">>;
+
+  const trimmedRight = str.trimRight();
+  type trimRightTest = Expect<Equal<typeof trimmedRight, "  hello">>;
+});
+
+doNotExecute(() => {
+  const str = "\thello\n" as const;
+
+  const trimmed = str.trim();
+  type trimTest = Expect<Equal<typeof trimmed, "hello">>;
+
+  const trimmedStart = str.trimStart();
+  type trimStartTest = Expect<Equal<typeof trimmedStart, "hello\n">>;
+
+  const trimmedEnd = str.trimEnd();
+  type trimEndTest = Expect<Equal<typeof trimmedEnd, "\thello">>;
+});
+
+doNotExecute(() => {
+  // Test with string literals that contain different whitespace combinations
+  const str = " \t\nhello world\t \n" as const;
+
+  const trimmed = str.trim();
+  type trimTest = Expect<Equal<typeof trimmed, "hello world">>;
+});
+
+doNotExecute(() => {
+  // Test with empty string and whitespace-only string
+  const emptyStr = "" as const;
+  const whitespaceStr = "   \t\n" as const;
+
+  const trimmedEmpty = emptyStr.trim();
+  type trimEmptyTest = Expect<Equal<typeof trimmedEmpty, "">>;
+
+  const trimmedWhitespace = whitespaceStr.trim();
+  type trimWhitespaceTest = Expect<Equal<typeof trimmedWhitespace, "">>;
+});
+
+doNotExecute(() => {
+  // Test with string type (not literals)
+  const str: string = "  hello  ";
+
+  const trimmed = str.trim();
+  type trimTest = Expect<Equal<typeof trimmed, string>>;
+
+  const trimmedStart = str.trimStart();
+  type trimStartTest = Expect<Equal<typeof trimmedStart, string>>;
+
+  const trimmedEnd = str.trimEnd();
+  type trimEndTest = Expect<Equal<typeof trimmedEnd, string>>;
+});