@brandon.cs/bnjs
v0.1.37JsResolver Proof Of Concept
Playground repo to prototype JsResolvers
Project Setup
- Install project dependencies
yarn install
- If you want to use a private RPC provider,
- Copy
.env_example
to init your own.env
file
- Copy
cp .env_example .env
- Complete your
.env
file with your private settings
Write a Js Resolver
- Create a new file in
src/resolvers
- Register your resolver main function using
JsResolverSdk.onChecker
- Example:
import { JsResolverSdk, JsResolverContext } from "../lib";
import { Contract, ethers } from "ethers";
import axios from "axios";
const ORACLE_ABI = [
"function lastUpdated() external view returns(uint256)",
"function updatePrice(uint256)",
];
JsResolverSdk.onChecker(async (context: JsResolverContext) => {
const { userArgs, gelatoArgs, secrets } = context;
// Use default ethers provider or your own using secrets api key
console.log('ChainId:', context.gelatoArgs.chainId)
const rpcProvider = ethers.getDefaultProvider(context.gelatoArgs.chainId, {
alchemy: await secrets.get("ALCHEMY_ID"),
});
// Retrieve Last oracle update time
const oracleAddress = "0x6a3c82330164822A8a39C7C0224D20DB35DD030a";
const oracle = new Contract(oracleAddress, ORACLE_ABI, rpcProvider);
const lastUpdated = parseInt(await oracle.lastUpdated());
console.log(`Last oracle update: ${lastUpdated}`);
// Check if it's ready for a new update
const nextUpdateTime = lastUpdated + 300; // 5 min
const timestamp = gelatoArgs.blockTime;
console.log(`Next oracle update: ${nextUpdateTime}`);
if (timestamp < nextUpdateTime) {
return { canExec: false, message: `Time not elapsed` };
}
// Get current price on coingecko
const currency = "ethereum";
const priceData = await axios.get(
`https://api.coingecko.com/api/v3/simple/price?ids=${currency}&vs_currencies=usd`
);
const price = Math.floor(priceData.data[currency].usd);
console.log(`Updating price: ${price}`);
// Return execution call data
return {
canExec: true,
callData: oracle.interface.encodeFunctionData("updatePrice", [price]),
};
});
- create your resolver
schema.json
to specify your runtime configuration:
{
"jsResolverVersion": "1.0.0",
"runtime": "node-18",
"memory": 128,
"timeout": 60,
"userArgs": {}
}
Test your resolver
Use
yarn test FILENAME
command to test your resolverOptions:
--show-logs
Show internal Resolver logs--runtime=thread|docker
Usethread
if you don't havedocker
set up locally (default:docker
)--debug
Show Runtime debug messages--user-args=[key]:[value]
Set your Resolver user args
Example:
yarn test src/resolvers/index.ts --show-logs --runtime=thread
Output:
JsResolver Build result: ✓ File: ./.tmp/resolver.cjs ✓ File size: 1.70mb ✓ Build time: 109.93ms JsResolver running logs: > ChainId: 5 > Last oracle update: 1665512172 > Next oracle update: 1665512472 > Updating price: 1586 JsResolver Result: ✓ Return value: { canExec: true, callData: '0x8d6cc56d0000000000000000000000000000000000000000000000000000000000000632' } JsResolver Runtime stats: ✓ Duration: 5.41s ✓ Memory: 57.77mb
Upload / fetch Js Resolver
Use yarn upload FILENAME
command to upload your resolver.
> yarn upload ./src/resolvers/index.ts
## Use User arguments
1. Declare your expected `userArgs` in you schema, accepted types are 'string', 'number' or 'float':
```json
{
"jsResolverVersion": "1.0.0",
"runtime": "node-18",
"memory": 128,
"timeout": 60,
"userArgs": {
"currency": "string",
"oracle": "string"
}
}
- Access your
userArgs
from the JsResolver context:
JsResolverSdk.onChecker(async (context: JsResolverContext) => {
const { userArgs, gelatoArgs, secrets } = context;
// User args:
console.log('Currency:', userArgs.currency)
console.log('Oracle:', userArgs.oracle)
});
- Pass
user-args
to the CLI to test your resolver:
yarn test src/resolvers/oracle/index.ts --show-logs --user-args=currency:ethereum --user-args=oracle:0x6a3c82330164822A8a39C7C0224D20DB35DD030a
Benchmark / Load testing
Use
yarn benchmark FILENAME
command to run a test loadOptions:
- all
test
command options --load=100
configure the number of resolver you want to run for your load test (default:10
)--pool=10
configure the pool size, ie max number of concurrent worker (default:10
)
- all
Example:
yarn benchmark src/resolvers/index.ts --load=100 --pool=10
Output:
Benchmark result: - nb success: 100/100 - duration: 64s
Failure tests
Some example failing file to test error handling
Syntax error in the resolver:
- Run:
yarn test src/resolvers/fails/syntax-error.js
- Result:
JsResolver building... ✘ [ERROR] Could not resolve "nothing" src/resolvers/fails/syntax-error.js:1:30: 1 │ import { JsResolverSdk } from "nothing"; ╵ ~~~~~~~~~ You can mark the path "nothing" as external to exclude it from the bundle, which will remove this error. JsResolver Build result: ✗ Error: Build failed with 1 error: src/resolvers/fails/syntax-error.js:1:30: ERROR: Could not resolve "nothing"
- Run:
No checker function registered in the resolver:
- Run:
yarn test src/resolvers/fails/not-registered.ts
- Result:
JsResolver Result: ✗ Error: JsResolver start-up timeout (5s) Make sure you registered your checker function correctly in your script.
- Run:
Resolver run out of memory:
- Run:
yarn test src/resolvers/fails/escape-memory.ts
- Result
JsResolver Result: ✗ Error: JsResolver sandbox exited with code=137 JsResolver Runtime stats: ✓ Duration: 1.91s ✗ Memory: 31.97mb
- Run:
Resolver exceed timeout:
- Run:
yarn test src/resolvers/fails/escape-timeout.ts
- Result:
JsResolver Result: ✗ Error: JsResolver exceed execution timeout (10s) JsResolver Runtime stats: ✗ Duration: 10.97s ✓ Memory: 25.34mb
- Run:
Resolver ends without returning result:
- Run:
yarn test src/resolvers/fails/no-result.js
- Result:
JsResolver Result: ✗ Error: JsResolver exited without returning result
- Run: