refactor: invoke ffmpeg without deprecated wrapper

tests/audio/ffmpegProcess.test.ts

@@ -0,0 +1,102 @@
+import { spawn } from "node:child_process";
+import { EventEmitter } from "node:events";
+import { describe, expect, it, vi } from "vitest";
+import { buildMuxFfmpegArgs, runFfmpeg } from "../../src/audio/ffmpegProcess";
+
+vi.mock("node:child_process", () => ({
+  spawn: vi.fn(),
+}));
+
+const spawnMock = vi.mocked(spawn);
+
+describe("buildMuxFfmpegArgs", () => {
+  it("builds args with multiple inputs and libmp3lame codec", () => {
+    const args = buildMuxFfmpegArgs({
+      inputs: ["a.ogg", "b.ogg"],
+      filter:
+        "[0:a]adelay=0|0[pad0];[1:a]adelay=1000|1000[pad1];[pad0][pad1]amix=inputs=2:dropout_transition=0[out]",
+      output: "out.mp3",
+      codec: "libmp3lame",
+    });
+
+    expect(args).toEqual([
+      "-y",
+      "-i",
+      "a.ogg",
+      "-i",
+      "b.ogg",
+      "-filter_complex",
+      "[0:a]adelay=0|0[pad0];[1:a]adelay=1000|1000[pad1];[pad0][pad1]amix=inputs=2:dropout_transition=0[out]",
+      "-map",
+      "[out]",
+      "-codec:a",
+      "libmp3lame",
+      "out.mp3",
+    ]);
+  });
+
+  it("includes audio frequency and channel options when provided", () => {
+    const args = buildMuxFfmpegArgs({
+      inputs: ["a.ogg"],
+      filter:
+        "[0:a]adelay=0|0[pad0];[pad0]amix=inputs=1:dropout_transition=0[out]",
+      output: "out.wav",
+      codec: "pcm_s16le",
+      audioFrequency: 44100,
+      audioChannels: 2,
+    });
+
+    expect(args).toContain("-ar");
+    expect(args).toContain("44100");
+    expect(args).toContain("-ac");
+    expect(args).toContain("2");
+  });
+
+  it("does not include -ar or -ac when audioFrequency and audioChannels are not provided", () => {
+    const args = buildMuxFfmpegArgs({
+      inputs: ["a.ogg"],
+      filter:
+        "[0:a]adelay=0|0[pad0];[pad0]amix=inputs=1:dropout_transition=0[out]",
+      output: "out.mp3",
+      codec: "libmp3lame",
+    });
+
+    expect(args).not.toContain("-ar");
+    expect(args).not.toContain("-ac");
+  });
+});
+
+describe("runFfmpeg", () => {
+  it("spawns ffmpeg and resolves on exit code 0", async () => {
+    const proc = new EventEmitter();
+    spawnMock.mockReturnValue(proc as ReturnType<typeof spawn>);
+
+    const result = runFfmpeg(["-version"]);
+    proc.emit("close", 0);
+
+    await expect(result).resolves.toBeUndefined();
+    expect(spawnMock).toHaveBeenCalledWith("ffmpeg", ["-version"], {
+      stdio: ["ignore", "inherit", "inherit"],
+    });
+  });
+
+  it("rejects on non-zero exit code", async () => {
+    const proc = new EventEmitter();
+    spawnMock.mockReturnValue(proc as ReturnType<typeof spawn>);
+
+    const result = runFfmpeg(["-bad"]);
+    proc.emit("close", 1);
+
+    await expect(result).rejects.toThrow("ffmpeg exited with code 1");
+  });
+
+  it("rejects on spawn error", async () => {
+    const proc = new EventEmitter();
+    spawnMock.mockReturnValue(proc as ReturnType<typeof spawn>);
+
+    const result = runFfmpeg(["-version"]);
+    proc.emit("error", new Error("spawn ffmpeg ENOENT"));
+
+    await expect(result).rejects.toThrow("spawn ffmpeg ENOENT");
+  });
+});