add trim method inference @ String.

package.json

@@ -74,6 +74,11 @@
       "import": "./dist/array-index-of.mjs",
       "default": "./dist/array-index-of.js"
     },
+    "./string-trim": {
+      "types": "./dist/string-trim.d.ts",
+      "import": "./dist/string-trim.mjs",
+      "default": "./dist/string-trim.js"
+    },
     "./dom": {
       "types": "./dist/dom.d.ts",
       "import": "./dist/dom.mjs",

src/entrypoints/string-trim.d.ts

@@ -0,0 +1,36 @@
+/// <reference path="utils.d.ts" />
+
+interface String {
+  trim<T extends string>(this: T): Trim<T>;
+  trimEnd<T extends string>(this: T): TrimEnd<T>;
+  /**
+   * Removes the leading white space and line terminator characters from a string.
+   * @deprecated A legacy feature for browser compatibility. Use `trimStart` instead
+   */
+  trimLeft<T extends string>(this: T): TrimStart<T>;
+  /**
+   * Removes the trailing white space and line terminator characters from a string.
+   * @deprecated A legacy feature for browser compatibility. Use `trimEnd` instead
+   */
+  trimRight<T extends string>(this: T): TrimEnd<T>;
+  trimStart<T extends string>(this: T): TrimStart<T>;
+}
+
+type Trim<T extends string> =
+  T extends `${Whitespace}${infer Middle}${Whitespace}`
+    ? Trim<Middle>
+    : T extends `${Whitespace}${infer Middle}`
+    ? TrimStart<Middle>
+    : T extends `${infer Middle}${Whitespace}`
+    ? TrimEnd<Middle>
+    : T;
+
+type TrimStart<T extends string> = T extends `${Whitespace}${infer Right}`
+  ? TrimStart<Right>
+  : T;
+
+type TrimEnd<T extends string> = T extends `${infer Left}${Whitespace}`
+  ? TrimEnd<Left>
+  : T;
+
+type Whitespace = " " | "\t" | "\n" | "\r";

src/tests/string-trim.ts

@@ -0,0 +1,66 @@
+import { doNotExecute } from "./utils";
+
+doNotExecute(async () => {
+  const str = "\n\t\r moshe \r\t\n";
+
+  function requireTrimmed<T extends string>(
+    _: T extends `${Whitespace}${string}` | `${string}${Whitespace}`
+      ? `Expected '${Trim<T>}', received '${T}'`
+      : T,
+  ) {}
+
+  // @ts-expect-error
+  requireTrimmed(str);
+  // @ts-expect-error
+  requireTrimmed(str.trimLeft());
+  // @ts-expect-error
+  requireTrimmed(str.trimStart());
+  // @ts-expect-error
+  requireTrimmed(str.trimRight());
+  // @ts-expect-error
+  requireTrimmed(str.trimEnd());
+
+  requireTrimmed(str.trim());
+});
+
+doNotExecute(async () => {
+  const str = "\n\t\r moshe \r\t\n";
+
+  function requireTrimmedStart<T extends string>(
+    _: T extends `${Whitespace}${string}`
+      ? `Expected '${TrimStart<T>}', received '${T}'`
+      : T,
+  ) {}
+
+  // @ts-expect-error
+  requireTrimmedStart(str);
+  // @ts-expect-error
+  requireTrimmedStart(str.trimRight());
+  // @ts-expect-error
+  requireTrimmedStart(str.trimEnd());
+
+  requireTrimmedStart(str.trimLeft());
+  requireTrimmedStart(str.trimStart());
+  requireTrimmedStart(str.trim());
+});
+
+doNotExecute(async () => {
+  const str = "\n\t\r moshe \r\t\n";
+
+  function requireTrimmedEnd<T extends string>(
+    _: T extends `${string}${Whitespace}`
+      ? `Expected '${TrimEnd<T>}', received '${T}'`
+      : T,
+  ) {}
+
+  // @ts-expect-error
+  requireTrimmedEnd(str);
+  // @ts-expect-error
+  requireTrimmedEnd(str.trimLeft());
+  // @ts-expect-error
+  requireTrimmedEnd(str.trimStart());
+
+  requireTrimmedEnd(str.trimEnd());
+  requireTrimmedEnd(str.trimRight());
+  requireTrimmedEnd(str.trim());
+});