Claude fixes

shared/src/helper/finite.ts

@@ -0,0 +1,60 @@
+import { vec2 } from 'gl-matrix';
+
+
+export const isFiniteNumber = (value: unknown): value is number =>
+  typeof value === 'number' && Number.isFinite(value);
+
+/** A finite number within [min, max], or `fallback` if the input is unusable. */
+export const finiteInRange = (
+  value: unknown,
+  min: number,
+  max: number,
+  fallback: number,
+): number => {
+  if (!isFiniteNumber(value)) {
+    return fallback;
+  }
+  return Math.min(max, Math.max(min, value));
+};
+
+/**
+ * A finite 2-vector whose magnitude is within `maxMagnitude`, or `undefined` if
+ * the input is not a usable pair of finite numbers. Callers should treat
+ * `undefined` as "drop this command" rather than substituting a default, so a
+ * malformed action is ignored instead of being silently reinterpreted.
+ */
+export const finiteVec2 = (value: unknown, maxMagnitude: number): vec2 | undefined => {
+  if (!value || typeof value !== 'object') {
+    return undefined;
+  }
+
+  const candidate = value as ArrayLike<unknown>;
+  if (candidate.length < 2) {
+    return undefined;
+  }
+
+  const x = candidate[0];
+  const y = candidate[1];
+  if (!isFiniteNumber(x) || !isFiniteNumber(y)) {
+    return undefined;
+  }
+
+  const result = vec2.fromValues(x, y);
+  const length = vec2.length(result);
+  if (length > maxMagnitude) {
+    vec2.scale(result, result, maxMagnitude / length);
+  }
+
+  return result;
+};
+
+/**
+ * A display name that is safe to store and re-serialize. Anything that is not a
+ * string is coerced, because a non-string survives `.slice()` — an array name
+ * round-trips through the serializer and is revived as a class on every peer
+ * that receives it, throwing inside the deserializer's reviver.
+ */
+export const sanitizeName = (value: unknown, maxLength: number): string => {
+  const text = typeof value === 'string' ? value : String(value ?? '');
+  return text.slice(0, maxLength);
+};