Added: trim sequence

Author: Mqxx

src/format/trim_sequence.test.ts

@@ -0,0 +1,46 @@
+import { assertEquals } from "https://deno.land/std@0.203.0/assert/assert_equals.ts";
+import trimSequence from './trim_sequence.ts';
+
+Deno.test(
+  'Trims a sequence from a string.',
+  async (test) => {
+    await test.step({
+      name: 'Empty input string',
+      fn: () => {
+        assertEquals(
+          trimSequence('', '123'),
+          ''
+        )
+      }
+    })
+    await test.step({
+      name: 'Empty sequence',
+      fn: () => {
+        assertEquals(
+          trimSequence('321abc123', ''),
+          '321abc123'
+        )
+      }
+    })
+
+    await test.step({
+      name: 'Normal input string',
+      fn: () => {
+        assertEquals(
+          trimSequence('321abc123', '123'),
+          '321abc'
+        )
+      }
+    })
+
+    await test.step({
+      name: 'Normal input string reversed',
+      fn: () => {
+        assertEquals(
+          trimSequence('321abc123', '321', true),
+          'abc'
+        )
+      }
+    })
+  }
+)

src/format/trim_sequence.ts

@@ -0,0 +1,27 @@
+import reverseString from './reverse_string.ts';
+import trimSequenceEnd from "./trim_sequence_end.ts";
+import trimSequenceStart from "./trim_sequence_start.ts";
+
+/**
+ * This function searches for the `sequence` at the start and end of the `inputString` and trims it.
+ * 
+ * @example
+ * ```
+ * console.log(trimSequence('321abc123', '123'))
+ * // 321abc
+ * 
+ * console.log(trimSequence('321abc123', '123', true))
+ * // abc
+ * ```
+ * @param inputString The input string to trim the start and end
+ * @param characters The characters to trim
+ * @param [reverse=false] If the end sequence to search should be reversed
+ * @returns The trimmed input string
+ */
+export default function trimSequence(
+  inputString : string,
+  sequence : string,
+  reverse : boolean = false
+) : string {
+  return trimSequenceStart(trimSequenceEnd(inputString, reverse ? reverseString(sequence) : sequence), sequence);
+}

src/format/trim_sequence_end.test.ts

@@ -0,0 +1,36 @@
+import { assertEquals } from "https://deno.land/std@0.203.0/assert/assert_equals.ts";
+import trimSequenceEnd from './trim_sequence_end.ts';
+
+Deno.test(
+  'Trims a sequence at the end of a string.',
+  async (test) => {
+    await test.step({
+      name: 'Empty input string',
+      fn: () => {
+        assertEquals(
+          trimSequenceEnd('', '123'),
+          ''
+        )
+      }
+    })
+    await test.step({
+      name: 'Empty sequence',
+      fn: () => {
+        assertEquals(
+          trimSequenceEnd('321abc123', ''),
+          '321abc123'
+        )
+      }
+    })
+
+    await test.step({
+      name: 'Normal input string',
+      fn: () => {
+        assertEquals(
+          trimSequenceEnd('321abc321', '321'),
+          '321abc'
+        )
+      }
+    })
+  }
+)

src/format/trim_sequence_end.ts

@@ -0,0 +1,28 @@
+/**
+ * This function searches for the `sequence` at the end of the `inputString` and trims it.
+ *
+ * @example
+ * ```
+ * console.log(trimSequenceEnd('1abc123', 'c123'))
+ * // 1ab
+ * ```
+ * @param inputString The input string to trim the end
+ * @param sequence The sequence to trim
+ * @returns The trimmed input string
+ */
+export default function trimSequenceEnd(
+  inputString : string,
+  sequence : string
+) : string {
+  if (!sequence || !sequence) {
+    return inputString;
+  }
+
+  const sequenceLength = sequence.length;
+
+  if (inputString.endsWith(sequence)) {
+    return inputString.slice(0, -sequenceLength);
+  }
+
+  return inputString;
+}

src/format/trim_sequence_start.test.ts

@@ -0,0 +1,36 @@
+import { assertEquals } from "https://deno.land/std@0.203.0/assert/assert_equals.ts";
+import trimSequenceStart from './trim_sequence_start.ts';
+
+Deno.test(
+  'Trims a sequence at the start of a string.',
+  async (test) => {
+    await test.step({
+      name: 'Empty input string',
+      fn: () => {
+        assertEquals(
+          trimSequenceStart('', '123'),
+          ''
+        )
+      }
+    })
+    await test.step({
+      name: 'Empty sequence',
+      fn: () => {
+        assertEquals(
+          trimSequenceStart('321abc123', ''),
+          '321abc123'
+        )
+      }
+    })
+
+    await test.step({
+      name: 'Normal input string',
+      fn: () => {
+        assertEquals(
+          trimSequenceStart('321abc321', '321'),
+          'abc321'
+        )
+      }
+    })
+  }
+)

src/format/trim_sequence_start.ts

@@ -0,0 +1,28 @@
+/**
+ * This function searches for the `sequence` at the start of the `inputString` and trims it.
+ *
+ * @example
+ * ```
+ * console.log(trimSequenceStart('1abc123', '1abc'))
+ * // 123
+ * ```
+ * @param inputString The input string to trim the start
+ * @param sequence The sequence to trim
+ * @returns The trimmed input string
+ */
+export default function trimSequenceStart(
+  inputString : string,
+  sequence : string
+) : string {
+  if (!sequence || !sequence) {
+    return inputString;
+  }
+
+  const sequenceLength = sequence.length;
+
+  if (inputString.startsWith(sequence)) {
+    return inputString.slice(sequenceLength);
+  }
+
+  return inputString;
+}