refactor: type application config

src/config.ts

@@ -1,4 +1,37 @@
 // Configuration for the bot
-export const config = {
-  verbose: process.argv.includes("-v") || process.argv.includes("--verbose"),
+export interface AppConfig {
+  verbose: boolean;
+  recordingsDir: string;
+  recordingSegmentMs: number;
+  decoderRotateMs: number;
+  decoderCooldownMs: number;
+}
+
+export function parseBoolean(
+  value: string | undefined,
+  fallback: boolean,
+): boolean {
+  if (value === "true") return true;
+  if (value === "false") return false;
+  return fallback;
+}
+
+export function parsePositiveNumber(
+  value: string | undefined,
+  fallback: number,
+): number {
+  const parsed = Number(value);
+  return Number.isFinite(parsed) && parsed > 0 ? parsed : fallback;
+}
+
+export function loadConfig(env: NodeJS.ProcessEnv = process.env): AppConfig {
+  return {
+    verbose: parseBoolean(env.VERBOSE, false),
+    recordingsDir: env.RECORDINGS_DIR ?? "./recordings",
+    recordingSegmentMs: parsePositiveNumber(env.RECORDING_SEGMENT_MS, 5_000),
+    decoderRotateMs: parsePositiveNumber(env.DECODER_ROTATE_MS, 5_000),
+    decoderCooldownMs: 30_000,
   };
+}
+
+export const config = loadConfig();

tests/config.test.ts

@@ -0,0 +1,17 @@
+import { describe, expect, it } from "vitest";
+import { parseBoolean, parsePositiveNumber } from "../src/config";
+
+describe("config parsers", () => {
+  it("parses boolean values", () => {
+    expect(parseBoolean("true", false)).toBe(true);
+    expect(parseBoolean("false", true)).toBe(false);
+    expect(parseBoolean(undefined, true)).toBe(true);
+  });
+
+  it("parses positive numbers", () => {
+    expect(parsePositiveNumber("5000", 0)).toBe(5000);
+    expect(parsePositiveNumber("0", 123)).toBe(123);
+    expect(parsePositiveNumber("bad", 123)).toBe(123);
+    expect(parsePositiveNumber(undefined, 123)).toBe(123);
+  });
+});