duplicate tool service and testCases, then updated index file

src/pages/list/duplicate/service.ts

@@ -0,0 +1,69 @@
+export type SplitOperatorType = 'symbol' | 'regex';
+
+function interweave(
+    array1: string[],
+    array2: string[]) {
+    const result: string[] = [];
+    const maxLength = Math.max(array1.length, array2.length);
+
+    for (let i = 0; i < maxLength; i++) {
+        if (i < array1.length) result.push(array1[i]);
+        if (i < array2.length) result.push(array2[i]);
+    }
+    return result;
+}
+function duplicate(
+    input: string[],
+    concatenate: boolean,
+    reverse: boolean,
+    copy?: number
+) {
+    if (copy) {
+        if (copy > 0) {
+            let result: string[] = [];
+            let toAdd: string[] = [];
+            let WholePart: string[] = [];
+            let fractionalPart: string[] = [];
+            const whole = Math.floor(copy);
+            const fractional = copy - whole;
+            if (!reverse) {
+                WholePart = concatenate ? Array(whole).fill(input).flat() : Array(whole - 1).fill(input).flat();
+                fractionalPart = input.slice(0, Math.floor(input.length * fractional));
+                toAdd = WholePart.concat(fractionalPart);
+                result = concatenate ? WholePart.concat(fractionalPart) : interweave(input, toAdd);
+            } else {
+                WholePart = Array(whole - 1).fill(input).flat().reverse()
+                fractionalPart = input.slice().reverse().slice(0, Math.floor(input.length * fractional));
+                toAdd = WholePart.concat(fractionalPart);
+                result = concatenate ? input.concat(toAdd) : interweave(input, toAdd);
+            }
+
+            return result;
+        }
+        throw new Error("Number of copies cannot be negative");
+    }
+    throw new Error("Number of copies must be a valid number");
+}
+
+export function duplicateList(
+    splitOperatorType: SplitOperatorType,
+    splitSeparator: string,
+    joinSeparator: string,
+    input: string,
+    concatenate: boolean,
+    reverse: boolean,
+    copy?: number
+): string {
+    let array: string[];
+    let result: string[];
+    switch (splitOperatorType) {
+        case 'symbol':
+            array = input.split(splitSeparator);
+            break;
+        case 'regex':
+            array = input.split(new RegExp(splitSeparator)).filter(item => item !== '');
+            break;
+    }
+    result = duplicate(array, concatenate, reverse, copy);
+    return result.join(joinSeparator);
+}