Test a Custom Template
Check exact spending authority and invalid inputs before creating a session.
Test builders locally before passing their output to the SDK. Tests should verify the exact permissions, network and expiry, plus important rejection cases. No API key, account funding or live transaction is required.
Set Up
Use native-allowance.ts from
Create a Custom Template, and install
a TypeScript runner:
npm install --save-dev tsxAssert the Granted Authority
Save this beside native-allowance.ts as native-allowance.test.ts:
import assert from "node:assert/strict";
import { test } from "node:test";
import { parseEther } from "viem";
import { nativeAllowanceTemplate } from "./native-allowance.js";
const now = 1_800_000_000;
const input = { allowanceWei: parseEther("0.001"), validUntil: now + 86_400 };
test("grants only the chosen lifetime allowance on Base Sepolia", () => {
assert.deepEqual(nativeAllowanceTemplate.build(input, { now }), {
onchain: {
installations: [
{
chainId: "eip155:84532",
validAfter: now,
validUntil: now + 86_400,
allowSignatures: false,
permissions: [{ type: "native-token-transfer", allowance: 1_000_000_000_000_000n }],
},
],
},
policies: [],
});
});
test("rejects non-positive amounts and uint256 overflow", () => {
for (const allowanceWei of [0n, -1n, 2n ** 256n]) {
assert.throws(() => nativeAllowanceTemplate.build({ ...input, allowanceWei }, { now }));
}
});
test("rejects an expired or equal deadline", () => {
for (const validUntil of [now - 1, now]) {
assert.throws(() => nativeAllowanceTemplate.build({ ...input, validUntil }, { now }));
}
});Run the Tests
npx tsx --test native-allowance.test.tsAll three tests should pass. The complete output assertion catches accidental root authority, signature grants, extra networks and changes to the allowance. When adding token support, test the verified deployment address and token decimals. For multiple networks, assert whether budgets are independent or shared.
These tests validate your builder. They do not prove deployment availability, onchain enforcement or successful installation. Complete the ordinary owner approval flow on a testnet before using a new template with real funds.