fix: address composite input contract review

2026-08-13 21:44:29 +07:00
parent 1bb684bfcd
commit cca1be891f
18 changed files with 455 additions and 172 deletions
@@ -0,0 +1,88 @@
+const isRecord = (value: unknown): value is Record<string, unknown> =>
+  typeof value === "object" && value !== null && !Array.isArray(value);
+
+export const MAX_INPUT_EXPRESSION_NODES = 1024;
+
+const expressionKinds = new Set(["literal", "path", "array", "object"]);
+
+/** Count expression nodes and containers nested inside literal values. */
+export const hasBoundedInputExpressionNodeBudget = (
+  input: unknown,
+  maxNodes: number = MAX_INPUT_EXPRESSION_NODES,
+): boolean => {
+  let nodes = 0;
+  const active = new WeakSet<object>();
+
+  const visitNode = (value: object): boolean => {
+    if (active.has(value)) return false;
+    active.add(value);
+    nodes += 1;
+    if (nodes > maxNodes) {
+      active.delete(value);
+      return false;
+    }
+    return true;
+  };
+
+  const visitJson = (value: unknown): boolean => {
+    if (typeof value !== "object" || value === null) return true;
+    if (!visitNode(value)) return false;
+    const valid = Array.isArray(value)
+      ? value.every(visitJson)
+      : Object.values(value).every(visitJson);
+    active.delete(value);
+    return valid;
+  };
+
+  const visitExpression = (value: unknown): boolean => {
+    if (!isRecord(value) || typeof value.kind !== "string") return false;
+    if (!expressionKinds.has(value.kind) || !visitNode(value)) return false;
+
+    let valid = true;
+    switch (value.kind) {
+      case "literal":
+        valid = visitJson(value.value);
+        break;
+      case "path":
+        break;
+      case "array":
+        valid = Array.isArray(value.items) && value.items.every(visitExpression);
+        break;
+      case "object":
+        valid = isRecord(value.fields) && Object.values(value.fields).every(visitExpression);
+        break;
+    }
+    active.delete(value);
+    return valid;
+  };
+
+  return visitExpression(input);
+};
+
+/** Find and bound generated expression-shaped values anywhere in an RPC value. */
+export const hasBoundedInputExpressionPayload = (
+  input: unknown,
+  maxNodes: number = MAX_INPUT_EXPRESSION_NODES,
+): boolean => {
+  const active = new WeakSet<object>();
+  const visit = (value: unknown): boolean => {
+    if (typeof value !== "object" || value === null) return true;
+    if (active.has(value)) return false;
+    active.add(value);
+    const valid = Array.isArray(value)
+      ? value.every(visit)
+      : isRecord(value) &&
+        (typeof value.kind === "string" &&
+        expressionKinds.has(value.kind) &&
+        ((value.kind === "literal" && "value" in value) ||
+          (value.kind === "path" && "path" in value) ||
+          (value.kind === "array" && Array.isArray(value.items)) ||
+          (value.kind === "object" && isRecord(value.fields)))
+          ? hasBoundedInputExpressionNodeBudget(value, maxNodes)
+          : Object.values(value).every(visit));
+    active.delete(value);
+    return valid;
+  };
+
+  return visit(input);
+};