Tidied up Luhn checksum op

src/core/operations/LuhnChecksum.mjs

@@ -36,7 +36,6 @@ class LuhnChecksum extends Operation {
     checksum(inputStr) {
         let even = false;
         return inputStr.split("").reverse().reduce((acc, elem) => {
-
             // Convert element to integer.
             let temp = parseInt(elem, 10);
 
@@ -46,7 +45,6 @@ class LuhnChecksum extends Operation {
 
             // If element is in an even position
             if (even) {
-
                 // Double the element and add the quotient and remainder together.
                 temp = 2 * elem;
                 temp = Math.floor(temp/10) + (temp % 10);
@@ -54,7 +52,6 @@ class LuhnChecksum extends Operation {
 
             even = !even;
             return acc + temp;
-
         }, 0)  % 10;
     }
 
@@ -64,16 +61,15 @@ class LuhnChecksum extends Operation {
      * @returns {string}
      */
     run(input, args) {
+        if (!input) return "";
 
-        if (!(input)) return "0";
-
-        const checkSum = this.checksum(input).toString();
-
-        let checkDigit = this.checksum(input+"0");
-
-        checkDigit =  (checkDigit === 0 ? 0 : (10-checkDigit)).toString();
+        const checkSum = this.checksum(input);
+        let checkDigit = this.checksum(input + "0");
+        checkDigit = checkDigit === 0 ? 0 : (10-checkDigit);
 
-        return "Checksum: " + checkSum + "\n\nCheckdigit: " + checkDigit + "\n\nLuhn Validated String: "+ input + checkDigit;
+        return `Checksum: ${checkSum}
+Checkdigit: ${checkDigit}
+Luhn Validated String: ${input + "" + checkDigit}`;
     }
 
 }

tests/operations/tests/LuhnChecksum.mjs

@@ -11,7 +11,7 @@ TestRegister.addTests([
     {
         name: "Luhn Checksum on standard data",
         input: "35641709012469",
-        expectedOutput: "Checksum: 7\n\nCheckdigit: 0\n\nLuhn Validated String: 356417090124690",
+        expectedOutput: "Checksum: 7\nCheckdigit: 0\nLuhn Validated String: 356417090124690",
         recipeConfig: [
             {
                 op: "Luhn Checksum",
@@ -22,7 +22,7 @@ TestRegister.addTests([
     {
         name: "Luhn Checksum on standard data 2",
         input: "896101950123440000",
-        expectedOutput: "Checksum: 5\n\nCheckdigit: 1\n\nLuhn Validated String: 8961019501234400001",
+        expectedOutput: "Checksum: 5\nCheckdigit: 1\nLuhn Validated String: 8961019501234400001",
         recipeConfig: [
             {
                 op: "Luhn Checksum",
@@ -33,7 +33,7 @@ TestRegister.addTests([
     {
         name: "Luhn Checksum on standard data 3",
         input: "35726908971331",
-        expectedOutput: "Checksum: 6\n\nCheckdigit: 7\n\nLuhn Validated String: 357269089713317",
+        expectedOutput: "Checksum: 6\nCheckdigit: 7\nLuhn Validated String: 357269089713317",
         recipeConfig: [
             {
                 op: "Luhn Checksum",
@@ -55,7 +55,7 @@ TestRegister.addTests([
     {
         name: "Luhn Checksum on empty data",
         input: "",
-        expectedOutput: "0",
+        expectedOutput: "",
         recipeConfig: [
             {
                 op: "Luhn Checksum",