Add demo for graph-watcher IPLD statediff and checkpointing

packages/graph-node/hardhat.config.ts

@@ -5,6 +5,7 @@
 import '@nomiclabs/hardhat-waffle';
 
 import './test/tasks/example-deploy';
+import './test/tasks/example-test';
 
 // You need to export an object to set up your config
 // Go to https://hardhat.org/config/ to learn more

packages/graph-node/package.json

@@ -42,7 +42,8 @@
     "build:example": "cd test/subgraph/example1 && yarn && yarn codegen && yarn build",
     "watch": "DEBUG=vulcanize:* nodemon --watch src src/watcher.ts",
     "compare-entity": "node bin/compare-entity",
-    "example:deploy": "hardhat --network localhost example-deploy"
+    "example:deploy": "hardhat --network localhost example-deploy",
+    "example:test": "hardhat --network localhost example-test"
   },
   "dependencies": {
     "@apollo/client": "^3.3.19",

packages/graph-node/test/tasks/example-test.ts

@@ -0,0 +1,31 @@
+//
+// Copyright 2022 Vulcanize, Inc.
+//
+
+import { task, types } from 'hardhat/config';
+import '@nomiclabs/hardhat-ethers';
+import { ContractTransaction } from 'ethers';
+
+task('example-test', 'Trigger Test event')
+  .addParam('address', 'Contract address', undefined, types.string)
+  .setAction(async (args, hre) => {
+    const { address } = args;
+    await hre.run('compile');
+    const Example = await hre.ethers.getContractFactory('Example');
+    const example = Example.attach(address);
+
+    const transaction: ContractTransaction = await example.emitEvent();
+
+    const receipt = await transaction.wait();
+
+    if (receipt.events) {
+      const TestEvent = receipt.events.find(el => el.event === 'Test');
+
+      if (TestEvent && TestEvent.args) {
+        console.log('Test Event');
+        console.log('param1:', TestEvent.args.param1.toString());
+        console.log('param2:', TestEvent.args.param2.toString());
+        console.log('param3:', TestEvent.args.param3.toString());
+      }
+    }
+  });