Added: Trim End Characters

Author: Mqxx

src/format/trim_characters_end.test.ts

@@ -0,0 +1,77 @@
+import { assertEquals } from "https://deno.land/std@0.203.0/assert/assert_equals.ts";
+import trimCharactersStart from "./trim_characters_end.ts";
+
+Deno.test(
+    'Trim characters at the end of a string.',
+    async (test) => {
+        await test.step({
+            name: 'Empty input string, empty characters',
+            fn: () => {
+                assertEquals(
+                    trimCharactersStart('', ''),
+                    ''
+                )
+            }
+        })
+
+        await test.step({
+            name: 'Empty characters',
+            fn: () => {
+                assertEquals(
+                    trimCharactersStart('abc123', ''),
+                    'abc123'
+                )
+            }
+        })
+
+        await test.step({
+            name: 'Empty input string',
+            fn: () => {
+                assertEquals(
+                    trimCharactersStart('', 'abc'),
+                    ''
+                )
+            }
+        })
+
+        await test.step({
+            name: 'Fake Escaped characters in input string',
+            fn: () => {
+                assertEquals(
+                    trimCharactersStart('\babc123\b', '\b'),
+                    '\babc123'
+                )
+            }
+        })
+
+        await test.step({
+            name: 'Real Escaped characters in input string',
+            fn: () => {
+                assertEquals(
+                    trimCharactersStart('abc123t\t', '\t'),
+                    'abc123t'
+                )
+            }
+        })
+
+        await test.step({
+            name: 'Skip characters in input string',
+            fn: () => {
+                assertEquals(
+                    trimCharactersStart('abc123', '1'),
+                    'abc123'
+                )
+            }
+        })
+
+        await test.step({
+            name: 'Normal trim',
+            fn: () => {
+                assertEquals(
+                    trimCharactersStart('abc123', '312ca'),
+                    'ab'
+                )
+            }
+        })
+    }
+)

src/format/trim_characters_end.ts

@@ -0,0 +1,21 @@
+/**
+ * This function is similar to the standard `String.prototype.trimEnd()` function. With this function, several characters
+ * can be specified as a string which are then trimmed at the end of the `inputString`.
+ * 
+ * @param inputString The input string to trim the end
+ * @param characters The characters to trim
+ * @returns The trimmed input string
+ */
+export default function trimCharactersStart(
+    inputString : string,
+    characters : string
+) : string {
+    const charactersSet = new Set(characters.split(''));
+    let endIndex = inputString.length - 1;
+
+    while (endIndex >= 0 && charactersSet.has(inputString[endIndex])) {
+        endIndex--;
+    }
+
+    return inputString.substring(0, endIndex + 1);
+}