From 1361f7da84967f8235a8ce8f4806edcb127dccac Mon Sep 17 00:00:00 2001
From: ranjeet2063 <ranjeet2063@users.noreply.github.com>
Date: Thu, 3 Sep 2026 15:10:45 +0545
Subject: [PATCH] fix(actions): reject non-finite amount values in
 createPaymentPrepTool (Closes #239)

---
 src/actions/payment-prep-action.ts |  6 +++++-
 tests/payment-prep-action.test.ts  | 31 ++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/src/actions/payment-prep-action.ts b/src/actions/payment-prep-action.ts
index ff5faed..75aca8b 100644
--- a/src/actions/payment-prep-action.ts
+++ b/src/actions/payment-prep-action.ts
@@ -52,7 +52,11 @@ export function createPaymentPrepTool(): ToolDefinition<
 
       const amountStr = String(payload.amount);
       const parsedAmount = Number(amountStr);
-      if (Number.isNaN(parsedAmount) || parsedAmount <= 0) {
+      if (
+        Number.isNaN(parsedAmount) ||
+        !Number.isFinite(parsedAmount) ||
+        parsedAmount <= 0
+      ) {
         throw new RuntimeError(
           "INVALID_TASK",
           "amount must be a positive number.",
diff --git a/tests/payment-prep-action.test.ts b/tests/payment-prep-action.test.ts
index 9e43e99..f4abf67 100644
--- a/tests/payment-prep-action.test.ts
+++ b/tests/payment-prep-action.test.ts
@@ -130,4 +130,35 @@ describe("PaymentPrepAction", () => {
       })
     ).toThrowError(RuntimeError);
   });
+
+  it("rejects non-finite amount values such as Infinity, NaN, and 1e309 with INVALID_TASK (issue #239)", async () => {
+    const tool = createPaymentPrepTool();
+    const context = createMockContext("task-pay-6");
+
+    const nonFiniteValues = [
+      "Infinity",
+      "-Infinity",
+      "NaN",
+      "1e309",
+      Infinity,
+      -Infinity,
+      NaN
+    ];
+
+    for (const amount of nonFiniteValues) {
+      try {
+        await tool.execute({
+          payload: {
+            walletId: "GWALLET123",
+            amount: amount as any
+          },
+          context
+        });
+        expect.unreachable();
+      } catch (err) {
+        expect(err).toBeInstanceOf(RuntimeError);
+        expect((err as RuntimeError).code).toBe("INVALID_TASK");
+      }
+    }
+  });
 });