#Testing your plugin

We'll create a few simple integration tests for the myAccount property of the NetworkConnection object.

We'll do it by using the Hardhat project in packages/plugin/test/fixture-projects/base-project as a test fixture.

The template repository comes with utilities to work with fixture projects. To learn more about them and other integration test strategies, read the Writing integration tests for plugins guide.

Now create a new file in packages/plugin/test/myAccount.ts and add the following code:

import assert from "node:assert/strict";
import { describe, it } from "node:test";

import { createFixtureProjectHRE } from "./helpers/fixture-projects.js";

describe("myAccount initialization on network connection", () => {
  it("should initialize the myAccount field on the network connection", async () => {
    const hre = await createFixtureProjectHRE("base-project");

    const connection = await hre.network.connect();
    const accounts: string[] = await connection.provider.request({
      method: "eth_accounts",
    });

    assert.equal(connection.myAccount, accounts[0]);
  });
});

This test uses the createFixtureProjectHRE function from the template project. It creates a new Hardhat Runtime Environment based on packages/plugin/test/fixture-projects/base-project/hardhat.config.ts.

Let's run pnpm test to make sure it works.

#Customizing the config of your fixture project

To test an error case where the myAccountIndex is too high, add this network config to packages/plugin/test/fixture-projects/base-project/hardhat.config.ts:

networks: {
  withMyAccountIndexTooHigh: {
    type: "edr-simulated",
    myAccountIndex: 100000,
  },
}

Now add this test to verify the error handling:

it("should throw a plugin error if the myAccountIndex is too high with respect to the accounts", async () => {
  const hre = await createFixtureProjectHRE("base-project");

  await assert.rejects(
    async () => {
      await hre.network.connect("withMyAccountIndexTooHigh");
    },
    HardhatPluginError, // Import it from "hardhat/plugins"
    "hardhat-plugin-template: Invalid index 100000 for myAccount when connecting to network withMyAccountIndexTooHigh"
  );
});

Run pnpm test to verify both tests pass.

#Complete test suite

You can find more tests of the plugin in the myAccount.ts test file in the tutorial branch of the template project.