feat: enhance order handling in LighterGateway and introduce order identity normalization for improved precision and consistency

src/exchanges/lighter/order-identity.ts

@@ -0,0 +1,35 @@
+/**
+ * Helpers for working with Lighter order identifiers without losing precision.
+ */
+
+/**
+ * Normalizes any order identifier into a trimmed string representation.
+ * Accepts string, number, or bigint inputs; returns null when the value
+ * cannot be represented as a meaningful identifier.
+ */
+export function normalizeOrderIdentity(value: unknown): string | null {
+  if (typeof value === "string") {
+    const trimmed = value.trim();
+    return trimmed.length > 0 ? trimmed : null;
+  }
+  if (typeof value === "number") {
+    if (!Number.isFinite(value)) {
+      return null;
+    }
+    return Math.trunc(value).toString(10);
+  }
+  if (typeof value === "bigint") {
+    return value.toString(10);
+  }
+  return null;
+}
+
+/**
+ * Compares two identifier-like values without casting through Number(),
+ * which would drop precision for large (>2^53) indices.
+ */
+export function orderIdentityEquals(a: unknown, b: unknown): boolean {
+  const left = normalizeOrderIdentity(a);
+  const right = normalizeOrderIdentity(b);
+  return left != null && right != null && left === right;
+}