Added Swiss standards function tryParseSwissIbanNumber

Author: dom-baur

CHANGELOG.md

@@ -10,7 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - `splitLines` string utility function
-- `formatSwissIbanNumber` swiss standard function
+- `tryParseSwissIbanNumber` swiss standard function
 - `trimStart`, `trimEnd` and `trim` string type utility functions
 
 ### Changed

src/lib/swissStandards.spec.ts

@@ -1,4 +1,4 @@
-import { isValidSwissIbanNumber, isValidSwissSocialInsuranceNumber, formatSwissIbanNumber } from "./swissStandards";
+import { isValidSwissIbanNumber, isValidSwissSocialInsuranceNumber, tryParseSwissIbanNumber } from "./swissStandards";
 
 describe("Swiss standards test", () => {
   test.each([
@@ -12,7 +12,7 @@ describe("Swiss standards test", () => {
     ["ch93 0076 2011 6238 5295 7", false],
     ["c93 0076 2011 6238 5295 7", false],
     ["DE93 0076 2011 6238 5295 7", false],
-  ])("check if the swiss IBAN number is valid or not", (iBanNumberToCheck, expected) => {
+  ])("check if the Swiss IBAN number is valid or not", (iBanNumberToCheck, expected) => {
     expect(isValidSwissIbanNumber(iBanNumberToCheck)).toBe(expected);
   });
 
@@ -25,7 +25,7 @@ describe("Swiss standards test", () => {
     ["DE34 0076 2ABC 123D EF45 3", false],
     ["CH34 0076 2ABC 123D EF45 \n6", false],
     ["CH34 0076 2ABC 123D EF45 !", false],
-  ])("check if the siwss IBAN number with letters is valid or not", (iBanNumberToCheck, expected) => {
+  ])("check if the Swiss IBAN number with letters is valid or not", (iBanNumberToCheck, expected) => {
     expect(isValidSwissIbanNumber(iBanNumberToCheck)).toBe(expected);
   });
 
@@ -45,18 +45,44 @@ describe("Swiss standards test", () => {
   });
 
   test.each([
-    [null as unknown as string, null, false],
-    [undefined as unknown as string, undefined, false],
-    ["CH9300762011623852957", "CH93 0076 2011 6238 5295 7", true],
-    ["ch9300762011623852957", "CH93 0076 2011 6238 5295 7", true],
-    ["ch9301234567891011127", "CH93 0123 4567 8910 1112 7", false],
-    ["DE93 00 76 2011 62385295 7", "DE93 00 76 2011 62385295 7", false],
-    ["D 93 00 76 2011 62385295 7", "D 93 00 76 2011 62385295 7", false],
-    ["Ch 93 0076 20 1 162385 295 7", "CH93 0076 2011 6238 5295 7", true],
-  ])("Check if the IBAN number gets formatted correctly", (unformattedIbanNumber, expectedIbanNumber, expectedIsValid) => {
-    const result = formatSwissIbanNumber(unformattedIbanNumber);
-
-    expect(result.ibanNumber).toBe(expectedIbanNumber);
-    expect(result.isValidSwissIbanNumber).toBe(expectedIsValid);
+    [null as unknown as string, { isValid: false, iban: undefined, ibanFormatted: undefined }],
+    [undefined as unknown as string, { isValid: false, iban: undefined, ibanFormatted: undefined }],
+    ["", { isValid: false, iban: undefined, ibanFormatted: undefined }],
+    ["CH94 0076 2011 6238 5295 7", { isValid: false, iban: undefined, ibanFormatted: undefined }],
+    ["CH1000000ABC123DEF456", { isValid: false, iban: undefined, ibanFormatted: undefined }],
+    [
+      "CH9300762011623852957",
+      {
+        isValid: true,
+        iban: "CH9300762011623852957",
+        ibanFormatted: "CH93 0076 2011 6238 5295 7",
+      },
+    ],
+    [
+      "CH3400762ABC123DEF456",
+      {
+        isValid: true,
+        iban: "CH3400762ABC123DEF456",
+        ibanFormatted: "CH34 0076 2ABC 123D EF45 6",
+      },
+    ],
+    [
+      "CH93 0076 2011 6238 5295 7",
+      {
+        isValid: true,
+        iban: "CH9300762011623852957",
+        ibanFormatted: "CH93 0076 2011 6238 5295 7",
+      },
+    ],
+    [
+      "CH34 0076 2ABC 123D EF45 6",
+      {
+        isValid: true,
+        iban: "CH3400762ABC123DEF456",
+        ibanFormatted: "CH34 0076 2ABC 123D EF45 6",
+      },
+    ],
+  ])("check if the Swiss IBAN number gets parsed correctly", (unformattedSwissIbanNumber, expected) => {
+    expect(tryParseSwissIbanNumber(unformattedSwissIbanNumber)).toEqual(expected);
   });
 });

src/lib/swissStandards.ts

@@ -109,41 +109,24 @@ export function isValidSwissSocialInsuranceNumber(socialInsuranceNumber: string)
 }
 
 /**
- * Formats a Swiss IBAN number to the standard of "CHXX XXXX XXXX XXXX XXXX X"
- * @param unformattedIbanNumber the IBAN number to format
- * @returns a object containing the formatted IBAN number and a boolean indicating if the IBAN number was valid or not
+ * Attempts to parse and validate a Swiss IBAN.
+ * @param unformattedIbanNumber - The unformatted IBAN as a string
+ * @returns The result object with the following properties:
+ * @property {boolean} isValid - Indicates whether the IBAN is valid or not
+ * @property {string} iban - The cleaned IBAN, only present if valid
+ * @property {string} ibanFormatted - The formatted IBAN, only present if valid
  */
-export function formatSwissIbanNumber(unformattedIbanNumber: string): {
-  /**
-   * The formatted IBAN number or the original input if the unformatted IBAN number was invalid
-   */
-  ibanNumber: string;
-  /**
-   * The result if the IBAN number is valid or not
-   */
-  isValidSwissIbanNumber: boolean;
-} {
-  // 1. Check if the unformatted IBAN number is empty or only a whitespace
+export function tryParseSwissIbanNumber(unformattedIbanNumber?: string) {
   if (isNullOrWhitespace(unformattedIbanNumber)) {
-    return { ibanNumber: unformattedIbanNumber, isValidSwissIbanNumber: false };
+    return { isValid: false };
   }
 
-  // 2. Remove all non-alphanumeric characters and convert letters to uppercase
-  const cleanedIbanNumber = unformattedIbanNumber.replaceAll(/[^A-Z0-9]/gi, "").toUpperCase();
-
-  // 3. Check if it is possible to format a new IBAN number
-  if (!/^CH\d{19}$/.test(cleanedIbanNumber)) {
-    return { ibanNumber: unformattedIbanNumber, isValidSwissIbanNumber: false };
-  }
-
-  // 4. Format the cleaned IBAN number into groups of 4 characters separated by spaces
-  const formattedIbanNumber = cleanedIbanNumber.replaceAll(/(.{4})/g, "$1 ").trim();
-
-  // 5. If the Swiss IBAN number is valid return the formatted IBAN number with the true status
-  if (isValidSwissIbanNumber(formattedIbanNumber)) {
-    return { ibanNumber: formattedIbanNumber, isValidSwissIbanNumber: true };
-  }
+  const iban = unformattedIbanNumber!.replaceAll(/[^A-Z0-9]/gi, "").toUpperCase();
+  const isValid = isValidSwissIbanNumber(iban);
 
-  // 6. If the Swiss IBAN number is not valid return the formatted IBAN number with the false status
-  return { ibanNumber: formattedIbanNumber, isValidSwissIbanNumber: false };
+  return {
+    isValid: isValid,
+    iban: isValid ? iban : undefined,
+    ibanFormatted: isValid ? iban.match(/.{1,4}/g)?.join(" ") : undefined,
+  };
 }