add example, fix null checks

Author: erhant

example/index.mjs

@@ -0,0 +1,58 @@
+import "dotenv/config";
+import { createPublicClient, createWalletClient, http } from "viem";
+import { privateKeyToAccount } from "viem/accounts";
+import { baseSepolia } from "viem/chains";
+import { Oracle } from "dria-oracle-sdk";
+
+async function main() {
+  const SECRET_KEY = process.env.SECRET_KEY;
+  const RPC_URL = process.env.RPC_URL ?? "https://base-sepolia-rpc.publicnode.com";
+  const COORDINATOR_ADDRESS = process.env.COORDINATOR_ADDRESS ?? "0x1deaca041f094ec67baa4fb36d333cb652e6b7a7";
+
+  // create oracle instance
+  const oracle = new Oracle({
+    public: createPublicClient({
+      chain: baseSepolia,
+      transport: http(RPC_URL),
+    }),
+    wallet: createWalletClient({
+      account: privateKeyToAccount(SECRET_KEY),
+      chain: baseSepolia,
+      transport: http(RPC_URL),
+    }),
+  });
+
+  await oracle.init(COORDINATOR_ADDRESS);
+
+  // check approval (you only need to do this once)
+  // you can ignore if you have gave allowance already
+  const allowance = await oracle.allowance();
+  if (allowance === 0n) {
+    console.log("Making allowance");
+    const txHash = await oracle.approve();
+    console.log({ txHash });
+  }
+
+  // make a request
+  const input = "What is the result of 2+2?";
+  const model = "*";
+  const requestTxHash = await oracle.request(input, model, {
+    taskParameters: {
+      numValidations: 0,
+    },
+  });
+  const taskId = await oracle.waitRequest(requestTxHash);
+
+  // wait for the result
+  await oracle.wait(taskId);
+
+  // read best result
+  const response = await oracle.read(taskId);
+  console.log({ response });
+
+  // read validations
+  const validations = await oracle.getValidations(taskId);
+  console.log({ validations });
+}
+
+main().catch(console.error);