Changed the name of the function ltrim to trimStart, the function rtrim to trimEnd and improved the code

Author: dom-baur

CHANGELOG.md

@@ -9,7 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
-- `ltrim`, `rtrim` and `trim` string type utility functions
+- `trimStart`, `trimEnd` and `trim` string type utility functions
 
 ### Changed
 

src/lib/string.spec.ts

@@ -1,4 +1,4 @@
-import { isNullOrEmpty, isNullOrWhitespace, capitalize, uncapitalize, truncate, ltrim, rtrim, trim } from "./string";
+import { isNullOrEmpty, isNullOrWhitespace, capitalize, uncapitalize, truncate, trimStart, trimEnd, trim } from "./string";
 
 describe("string tests", () => {
   test.each([
@@ -128,7 +128,7 @@ describe("string tests", () => {
     ["hello world", " ", "hello world"],
     [" hello world", " ", "hello world"],
   ])("left trim", (haystack, needle, expected) => {
-    expect(ltrim(haystack, needle)).toBe(expected);
+    expect(trimStart(haystack, needle)).toBe(expected);
   });
 
   test.each([
@@ -138,14 +138,17 @@ describe("string tests", () => {
     ["hello world ", " ", "hello world"],
     ["hello world", " ", "hello world"],
   ])("right trim", (haystack, needle, expected) => {
-    expect(rtrim(haystack, needle)).toBe(expected);
+    expect(trimEnd(haystack, needle)).toBe(expected);
   });
 
   test.each([
     [null as unknown as string, " ", null as unknown as string],
     [undefined as unknown as string, " ", undefined as unknown as string],
     ["hello world", "", "hello world"],
     [" hello world ", " ", "hello world"],
+    ["hello world ", " ", "hello world"],
+    [" hello world", " ", "hello world"],
+    ["hello worldhello world", "hello world", ""],
   ])("trim", (haystack, needle, expected) => {
     expect(trim(haystack, needle)).toBe(expected);
   });

src/lib/string.ts

@@ -71,17 +71,15 @@ export function truncate(value: string | undefined, maxLength: number, suffix =
  * @param needle the thing to trim
  * @returns the string trimmed from the left side
  */
-export function ltrim(haystack: string, needle: string): string {
+export function trimStart(haystack: string, needle: string): string {
   if (isNullOrEmpty(haystack) || isNullOrEmpty(needle)) {
     return haystack;
   }
 
-  const needleLength = needle.length;
-
   let offset = 0;
 
   while (haystack.indexOf(needle, offset) === offset) {
-    offset = offset + needleLength;
+    offset = offset + needle.length;
   }
   return haystack.slice(offset);
 }
@@ -92,20 +90,17 @@ export function ltrim(haystack: string, needle: string): string {
  * @param needle the thing to trim
  * @returns the string trimmed from the right side
  */
-export function rtrim(haystack: string, needle: string): string {
+export function trimEnd(haystack: string, needle: string): string {
   if (isNullOrEmpty(haystack) || isNullOrEmpty(needle)) {
     return haystack;
   }
 
-  const needleLength = needle.length,
-    haystackLength = haystack.length;
-
-  let offset = haystackLength,
+  let offset = haystack.length,
     idx = -1;
 
   while (true) {
     idx = haystack.lastIndexOf(needle, offset - 1);
-    if (idx === -1 || idx + needleLength !== offset) {
+    if (idx === -1 || idx + needle.length !== offset) {
       break;
     }
     if (idx === 0) {
@@ -124,6 +119,6 @@ export function rtrim(haystack: string, needle: string): string {
  * @returns the string trimmed from the right and left side
  */
 export function trim(haystack: string, needle: string): string {
-  const trimmed = ltrim(haystack, needle);
-  return rtrim(trimmed, needle);
+  const trimmed = trimStart(haystack, needle);
+  return trimEnd(trimmed, needle);
 }