From 4a4e82daba45992a237306713d2f64d75bd9ce17 Mon Sep 17 00:00:00 2001
From: NetterSilver <133535268+Silvertree2010@users.noreply.github.com>
Date: Sat, 17 Oct 2026 09:54:08 +0200
Subject: [PATCH] Reject missing or non-numeric values in mix.pan and mix.trim

Found while testing crates/engine/src/cmd/mix.rs:237 (pan); same pattern at mix.rs:76 (mix.trim)

Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
---
 crates/engine/src/cmd/mix.rs               |  6 ++--
 crates/engine/tests/mix_required_params.rs | 42 ++++++++++++++++++++++
 2 files changed, 46 insertions(+), 2 deletions(-)
 create mode 100644 crates/engine/tests/mix_required_params.rs

diff --git a/crates/engine/src/cmd/mix.rs b/crates/engine/src/cmd/mix.rs
index c0569429..faddc6ca 100644
--- a/crates/engine/src/cmd/mix.rs
+++ b/crates/engine/src/cmd/mix.rs
@@ -73,7 +73,8 @@ pub fn specs() -> Vec<CommandSpec> {
         )),
         cmd!("mix.trim", "Input Trim", [], None, "{tracks?, db}", has_selection, |e, p| {
             let tracks = tracks_required(e, "mix.trim", p)?;
-            let db = f32_or(p, "db", 0.0).clamp(-144.0, 24.0);
+            let db = (p.get("db").and_then(Value::as_f64).filter(|v| v.is_finite()).ok_or_else(|| bad("mix.trim", "`db` (number) required"))? as f32)
+                .clamp(-144.0, 24.0);
             let s = e.session_mut();
             for t in tracks {
                 if let Some(tr) = s.track_mut(t) {
@@ -234,7 +235,8 @@ fn volume(e: &mut Engine, p: &Value) -> Result<Value> {
 
 fn pan(e: &mut Engine, p: &Value) -> Result<Value> {
     let tracks = tracks_required(e, "mix.pan", p)?;
-    let v = f32_or(p, "pan", 0.0).clamp(-1.0, 1.0);
+    let v = (p.get("pan").and_then(Value::as_f64).filter(|v| v.is_finite()).ok_or_else(|| bad("mix.pan", "`pan` (number) required"))? as f32)
+        .clamp(-1.0, 1.0);
     let idx = i64_or(p, "index", 0).clamp(0, 1) as usize;
     let s = e.session_mut();
     for t in &tracks {
diff --git a/crates/engine/tests/mix_required_params.rs b/crates/engine/tests/mix_required_params.rs
new file mode 100644
index 00000000..f11e2f31
--- /dev/null
+++ b/crates/engine/tests/mix_required_params.rs
@@ -0,0 +1,42 @@
+use serde_json::json;
+use soundcraft_engine::{Engine, EngineError};
+
+fn engine_with_kick() -> Engine {
+    let mut e = Engine::default();
+    e.execute("track.new", &json!({"name": "Kick", "format": "stereo"})).unwrap();
+    e
+}
+
+fn kick_pan(e: &Engine) -> Vec<f32> {
+    e.session().tracks.iter().find(|t| t.name == "Kick").unwrap().mixer.pan.to_vec()
+}
+
+fn kick_trim(e: &Engine) -> f32 {
+    e.session().tracks.iter().find(|t| t.name == "Kick").unwrap().mixer.trim_db
+}
+
+#[test]
+fn mix_pan_rejects_a_missing_or_non_numeric_pan_and_keeps_the_pan() {
+    let mut e = engine_with_kick();
+    e.execute("mix.pan", &json!({"tracks": ["Kick"], "pan": -1.0})).unwrap();
+    assert_eq!(kick_pan(&e)[0], -1.0);
+
+    for params in [json!({"tracks": ["Kick"]}), json!({"tracks": ["Kick"], "pan": "left"}), json!({"tracks": ["Kick"], "pan": null})] {
+        let r = e.execute("mix.pan", &params);
+        assert!(matches!(r, Err(EngineError::BadParams(..))), "{params}: expected BadParams, got {r:?}");
+        assert_eq!(kick_pan(&e)[0], -1.0, "{params}: the pan must be untouched");
+    }
+}
+
+#[test]
+fn mix_trim_rejects_a_missing_or_non_numeric_db_and_keeps_the_trim() {
+    let mut e = engine_with_kick();
+    e.execute("mix.trim", &json!({"tracks": ["Kick"], "db": -6.0})).unwrap();
+    assert_eq!(kick_trim(&e), -6.0);
+
+    for params in [json!({"tracks": ["Kick"]}), json!({"tracks": ["Kick"], "db": "loud"}), json!({"tracks": ["Kick"], "db": null})] {
+        let r = e.execute("mix.trim", &params);
+        assert!(matches!(r, Err(EngineError::BadParams(..))), "{params}: expected BadParams, got {r:?}");
+        assert_eq!(kick_trim(&e), -6.0, "{params}: the trim must be untouched");
+    }
+}