Review: width-point removal reuses point_indices; ROADMAP (#1079)

point_indices moves from freeform.rs to the cmd param helpers so
stroke.widthPoint.remove parses `index` and `indices` with it, and a
malformed entry reports the translated "no such width point".

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/engine/src/cmd/distortcmds.rs

@@ -323,23 +323,13 @@ fn width_point_copy(s: &mut Session, p: &Value) -> Result<Value> {
 fn width_point_remove(s: &mut Session, p: &Value) -> Result<Value> {
     const C: &str = "stroke.widthPoint.remove";
     let id = id_param(p, "id").ok_or_else(|| bad(C, "missing id"))?;
-    let mut indices: Vec<usize> = match p.get("indices") {
-        Some(Value::Array(values)) => values
-            .iter()
-            .map(|value| {
-                let id = value.as_u64().ok_or_else(|| bad(C, format!("invalid width point index {value}: expected an integer")))?;
-                usize::try_from(id).map_err(|_| bad(C, format!("width point index {id} is out of range")))
-            })
-            .collect::<Result<_>>()?,
-        Some(_) => return Err(bad(C, "indices must be an array of non-negative integers")),
-        None => match p.get("index") {
-            Some(value) => {
-                let id = value.as_u64().ok_or_else(|| bad(C, "index must be a non-negative integer"))?;
-                vec![usize::try_from(id).map_err(|_| bad(C, "index is out of range"))?]
-            }
-            None => return Err(bad(C, "missing index")),
-        },
+    let indices = match (p.get("indices"), p.get("index")) {
+        (Some(a), _) => point_indices(a),
+        (None, Some(i)) => point_indices(&json!([i])),
+        (None, None) => return Err(bad(C, "missing index")),
     };
+    // A malformed index fails the whole delete instead of being dropped while the others go.
+    let mut indices = indices.ok_or_else(|| bad(C, "no such width point"))?;
     indices.sort_unstable();
     indices.dedup();
     s.edit("Delete Width Point", |d, _| {

crates/engine/src/cmd/freeform.rs

@@ -161,12 +161,6 @@ pub(crate) fn parse_freeform(v: &Value) -> std::result::Result<Freeform, String>
     Ok(f)
 }
 
-/// `v` as a list of point indices: `None` unless it is an array of non-negative integers, so no
-/// malformed index is dropped or wrapped round.
-fn point_indices(v: &Value) -> Option<Vec<usize>> {
-    v.as_array()?.iter().map(|i| usize::try_from(i.as_u64()?).ok()).collect()
-}
-
 pub(crate) fn parse_mode(m: &str) -> std::result::Result<FreeformMode, String> {
     FreeformMode::parse(m).ok_or_else(|| format!("unknown freeform mode `{m}` (points, lines)"))
 }

crates/engine/src/cmd/mod.rs

@@ -340,6 +340,12 @@ pub(crate) fn finite_numbers<const N: usize>(v: &Value) -> Option<[f64; N]> {
     Some(out)
 }
 
+/// `v` as a list of point indices: `None` unless it is an array of non-negative integers, so no
+/// malformed index is dropped or wrapped round.
+pub(crate) fn point_indices(v: &Value) -> Option<Vec<usize>> {
+    v.as_array()?.iter().map(|i| usize::try_from(i.as_u64()?).ok()).collect()
+}
+
 pub(crate) fn point_param(p: &Value, key: &str) -> Option<Point> {
     let a = p.get(key)?.as_array()?;
     Some(Point::new(a.first()?.as_f64()?, a.get(1)?.as_f64()?))