Add Swiss standards function tryParseSwissIbanNumber (#81)

Add Swiss standards function tryParseSwissIbanNumber for issue #77

Author: dom-baur

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - `splitLines` string utility 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 } from "./swissStandards";
+import { isValidSwissIbanNumber, isValidSwissSocialInsuranceNumber, tryParseSwissIbanNumber } from "./swissStandards";
 
 describe("Swiss standards test", () => {
   test.each([
@@ -10,8 +10,9 @@ describe("Swiss standards test", () => {
     ["CH93-0076-2011-6238-5295-7", false],
     ["CH93 0000 0000 0000 0000 1", false],
     ["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);
   });
 
@@ -24,7 +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);
   });
 
@@ -39,7 +40,22 @@ describe("Swiss standards test", () => {
     ["756.1234.5678.91", false],
     ["test756.9217.0769.85", false],
     ["7.56..9217...0769.85", false],
-  ])("check if the social insurance number is valid or not", (socialInsuranceNumberToCheck, expected) => {
-    expect(isValidSwissSocialInsuranceNumber(socialInsuranceNumberToCheck)).toBe(expected);
+  ])("check if the social insurance number is valid or not", (swissSocialInsuranceNumber, expected) => {
+    expect(isValidSwissSocialInsuranceNumber(swissSocialInsuranceNumber)).toBe(expected);
+  });
+
+  test.each([
+    [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 }],
+    ["CH93-0076,2011.6238\n5295\n7", { isValid: true, iban: "CH9300762011623852957", ibanFormatted: "CH93 0076 2011 6238 5295 7" }],
+    ["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

@@ -107,3 +107,26 @@ export function isValidSwissSocialInsuranceNumber(socialInsuranceNumber: string)
    */
   return checksum === checknumber;
 }
+
+/**
+ * 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 tryParseSwissIbanNumber(unformattedIbanNumber?: string) {
+  if (isNullOrWhitespace(unformattedIbanNumber)) {
+    return { isValid: false };
+  }
+
+  const iban = unformattedIbanNumber!.replaceAll(/[^A-Z0-9]/gi, "").toUpperCase();
+  const isValid = isValidSwissIbanNumber(iban);
+
+  return {
+    isValid: isValid,
+    iban: isValid ? iban : undefined,
+    ibanFormatted: isValid ? iban.match(/.{1,4}/g)?.join(" ") : undefined,
+  };
+}