Fix FinTS TIME formatting and coverage

packages/fints/src/__tests__/test-format.ts

@@ -0,0 +1,15 @@
+import { Format } from "../format";
+
+// FinTS 3.0 Formals TIME datatype (https://www.hbci-zka.de/downloads/FinTS_3_0/FinTS3.0_Formals_2010-12-20_final_version.pdf)
+// specifies HHmmss with minutes rather than months.
+describe("Format.time", () => {
+    it("formats hours, minutes, and seconds as HHmmss", () => {
+        const date = new Date(Date.UTC(2024, 11, 24, 8, 3, 45));
+        expect(Format.time(date)).toBe("080345");
+    });
+
+    it("does not substitute the month for minutes", () => {
+        const date = new Date(Date.UTC(2024, 5, 15, 12, 59, 1));
+        expect(Format.time(date)).toBe("125901");
+    });
+});

packages/fints/src/__tests__/test-pin-tan-client.ts

@@ -15,8 +15,8 @@ const productId = "fints";
 let client: PinTanClient;
 
 beforeEach(() => {
-    jest.spyOn(Format, "date").mockImplementation((date) => (date ? format(date, "HHMMss") : "20180101"));
-    jest.spyOn(Format, "time").mockImplementation((time) => (time ? format(time, "HHMMss") : "120000"));
+    jest.spyOn(Format, "date").mockImplementation((date) => (date ? format(date, "yyyyMMdd") : "20180101"));
+    jest.spyOn(Format, "time").mockImplementation((time) => (time ? format(time, "HHmmss") : "120000"));
     jest.spyOn(Math, "random").mockReturnValue(0.5);
     client = new PinTanClient({ blz, name, pin, url, productId });
 });

packages/fints/src/format.ts

@@ -86,7 +86,8 @@ export const Format = {
      */
     time(date?: Date) {
         const dateToFormat = date ? date : new Date();
-        return format(dateToFormat, "HHMMss");
+        // FinTS 3.0 Formals (TIME datatype) requires HHmmss with minutes, see https://www.hbci-zka.de/downloads/FinTS_3_0/FinTS3.0_Formals_2010-12-20_final_version.pdf.
+        return format(dateToFormat, "HHmmss");
     },
     /**
      * Return an empty string.