Cleaned up the frame.ts by splitting payload parsing to subpackages

test/frame.test.ts

@@ -1,7 +1,7 @@
 import { Dissected, FieldType } from "@hamradio/packet";
 import { describe, expect, it } from "vitest";
 
-import { Address, Frame, Timestamp } from "../src/frame";
+import { Address, Frame } from "../src/frame";
 import {
   DataType,
   type ITimestamp,
@@ -12,6 +12,7 @@ import {
   type PositionPayload,
   type StatusPayload
 } from "../src/frame.types";
+import Timestamp from "../src/timestamp";
 
 // Address parsing: split by method
 describe("Address.parse", () => {

test/payload.extras.test.ts

@@ -4,6 +4,7 @@ import { describe, expect, it } from "vitest";
 import { Frame } from "../src/frame";
 import type { PositionPayload } from "../src/frame.types";
 import { feetToMeters, milesToMeters } from "../src/parser";
+import { decodeTelemetry } from "../src/payload.extras";
 
 describe("APRS extras test vectors", () => {
   it("parses altitude token in the beginning of a comment and emits structure", () => {
@@ -175,3 +176,49 @@ describe("APRS extras test vectors", () => {
     expect(commentIndex).toBeGreaterThan(altitudeIndex); // Comment comes after altitude
   });
 });
+
+describe("decodeTelemetry", () => {
+  it("decodes minimal telemetry (|!!!!|)", () => {
+    const result = decodeTelemetry("!!!!");
+    expect(result.sequence).toBe(0);
+    expect(result.analog).toEqual([0]);
+    expect(result.digital).toBeUndefined();
+  });
+
+  it("decodes sequence and one channel", () => {
+    const result = decodeTelemetry("ss11");
+    expect(result.sequence).toBe(7544);
+    expect(result.analog).toEqual([1472]);
+    expect(result.digital).toBeUndefined();
+  });
+
+  it("decodes sequence and two channels", () => {
+    const result = decodeTelemetry("ss1122");
+    expect(result.sequence).toBe(7544);
+    expect(result.analog).toEqual([1472, 1564]);
+    expect(result.digital).toBeUndefined();
+  });
+
+  it("decodes sequence and five channels", () => {
+    const result = decodeTelemetry("ss1122334455");
+    expect(result.sequence).toBe(7544);
+    expect(result.analog).toEqual([1472, 1564, 1656, 1748, 1840]);
+    expect(result.digital).toBeUndefined();
+  });
+
+  it("decodes sequence, five channels, and digital", () => {
+    const result = decodeTelemetry('ss1122334455!"');
+    expect(result.sequence).toBe(7544);
+    expect(result.analog).toEqual([1472, 1564, 1656, 1748, 1840]);
+    expect(result.digital).toBe(1);
+  });
+
+  it("throws on too short input", () => {
+    expect(() => decodeTelemetry("!")).toThrow();
+    expect(() => decodeTelemetry("")).toThrow();
+  });
+
+  it("throws on invalid base91", () => {
+    expect(() => decodeTelemetry("ss11~~")).toThrow();
+  });
+});