refactor(audio): extract AddonContext + NapiHelpers, guard raw N-API args (phase 6)

AddonContext (src/audio/addon/): engine/vstHost lifetime + snapshot rule, the JUCE message thread with the macOS no-pump fork quarantined into ONE file, the shutdown latch (exposed as isShuttingDown), doShutdown with a UI teardown hook (NodeAddon points it at the editor-window nuke, #56), and the pending-async-load registry. NodeAddon keeps using-declarations so the binding bodies are unchanged. Also fixes SetBackingSpeed's bare `engine` dereference — the one binding that dodged the file's own snapshot rule. NapiHelpers (typed extractors argInt/argSlotId/argFiniteFloat/argBool/ argMidiChannel/argMidiByte) + rewrites of the unguarded bindings — the deep-read §2 fix, done once: SetParameter/SetBypass/RemoveProcessor/ MoveProcessor/SetMultiBypass/SendMidiToSlot/SetGain plus the St-1 routing quartet (SetPan/SetPostGain/SetBranch/SetBranchSrc). NaN slot ids no longer coerce to slot 0; MIDI channel/program are range-checked before JUCE. New gate: tests/napi-arg-fuzz.test.js — table-driven garbage (NaN/Inf/ negative/string/missing/object) against the real addon; chain state must be byte-identical after the storm and a valid call must still apply. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-09-11 01:44:11 +00:00 · 2026-07-14 01:41:07 +02:00
parent 6b0bfb7be3
commit d4e0bfc272
6 changed files with 527 additions and 295 deletions
@@ -0,0 +1,75 @@
+// Phase 6 gate (docs/audio-engine-tlc.md §5, deep-read §2): table-driven
+// argument fuzz against the real addon. Every chain-mutating binding must
+// treat NaN/Infinity/negative/string/missing/object arguments as a clean
+// no-op — historically Int32Value() coerced NaN → 0 and mutated SLOT 0.
+// Quarantined behind the addon being built (CI native lane), auto-skips
+// otherwise. Uses no audio device (engine constructed, never started).
+'use strict';
+
+const test = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const os = require('node:os');
+const path = require('node:path');
+
+const ADDON = path.join(__dirname, '..', 'build', 'Release', 'slopsmith_audio.node');
+const HAVE_ADDON = fs.existsSync(ADDON);
+
+function writeImpulseWav(file) {
+    const buf = Buffer.alloc(44 + 128);
+    buf.write('RIFF', 0); buf.writeUInt32LE(36 + 128, 4); buf.write('WAVE', 8);
+    buf.write('fmt ', 12); buf.writeUInt32LE(16, 16); buf.writeUInt16LE(1, 20);
+    buf.writeUInt16LE(1, 22); buf.writeUInt32LE(48000, 24); buf.writeUInt32LE(96000, 28);
+    buf.writeUInt16LE(2, 32); buf.writeUInt16LE(16, 34);
+    buf.write('data', 36); buf.writeUInt32LE(128, 40);
+    buf.writeInt16LE(32767, 44);
+    fs.writeFileSync(file, buf);
+}
+
+const GARBAGE = [NaN, Infinity, -Infinity, -1, 1.5, 4097, 'x', null, undefined, {}, []];
+
+test('chain-mutating bindings no-op on garbage args and never touch slot 0', { skip: !HAVE_ADDON && 'addon not built' }, async () => {
+    const audio = require(ADDON);
+    audio.init();
+    const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'arg-fuzz-'));
+    const ir = path.join(tmp, 'i.wav');
+    writeImpulseWav(ir);
+    try {
+        const res = await audio.loadPreset(JSON.stringify({
+            chain: [{ type: 2, name: 'fuzz-anchor', path: ir, bypassed: false }],
+        }));
+        assert.ok(res?.success, 'anchor preset must load');
+        const before = JSON.stringify(audio.getChainState());
+
+        for (const g of GARBAGE) {
+            audio.setBypass(g, true);
+            audio.setBypass(0 /* valid id shape */, g);
+            audio.removeProcessor(g);
+            audio.moveProcessor(g, 0);
+            audio.moveProcessor(0, g);
+            audio.setParameter(g, 0, 0.5);
+            audio.setParameter(1, g, 0.5);
+            audio.setParameter(1, 0, g);
+            audio.setPan?.(g, 0);
+            audio.sendMidiToSlot(g, 0, 1, 0);
+            audio.sendMidiToSlot(1, g, 1, 0);
+            audio.sendMidiToSlot(1, 0, g, 0);
+            audio.sendMidiToSlot(1, 0, 1, g);
+            audio.setMultiBypass([{ slotId: g, bypassed: true }, g, null]);
+            audio.setGain('output', g);
+            audio.setGain(g, 1);
+        }
+
+        const after = JSON.stringify(audio.getChainState());
+        assert.equal(after, before, 'garbage args must not mutate any slot');
+        // Sanity: a VALID call still works after the fuzz storm.
+        audio.setBypass(1, true);
+        const st = audio.getChainState();
+        assert.equal(st[0]?.bypassed, true, 'valid call after fuzz must apply');
+        audio.setBypass(1, false);
+    } finally {
+        await audio.clearChain?.();
+        audio.shutdown?.();
+        fs.rmSync(tmp, { recursive: true, force: true });
+    }
+});