# hardhat-helpers

Test helpers for Hardhat.

`yarn add hardhat-helpers`

## Snapshot Each

Replaces the first `beforeEach` in a test file to improve performance similar to Hardhat's fixtures -- but with a more familiar syntax.

Example:

```typescript
import { snapshotEach } from "hardhat-helpers";

let someContract;

snapshotEach(async () => {
  someContract = await deployContract();
});

it("Test like normal", async () => {
  expect(await someContract.method()).toEqual(42);
});

it("Next test reuses the original deployment", async () => {
  expect(await someContract.otherMethod()).toEqual(69);
});
```

It runs like normal for the first test, and then each additional test rolls back the node instead of redeploying.

## Expect All Events

Checks the tx for the exact logs specified including order, count, and args.

```typescript
import { expectAllEvents } from "hardhat-helpers";

it("Emits", async () => {
  const tx = await magicContract.magic();
  await expectAllEvents(tx, [
    {
      contract: magicContract,
      event: "MagicStarted",
      args: [42],
    },
    {
      contract: magicContract,
      event: "MagicHappened",
      args: [69],
    },
  ]);
});
```

## Time Travel

Simple helpers to modify the block time in tests. Several variations are supported: see [time.ts](./src/time.ts) for a complete list.

```typescript
import { increaseTime } from "hardhat-helpers";

it("Do something later", async () => {
  await timeContract.queue();
  await increaseTime(10); // in seconds
  await timeContract.process();
});
```

## And more...

TODO: more docs

- [balance](./src/balance.ts)
- [fork](./src/fork.ts)
  - Forked contracts: [dai](./src/mainnet/dai.ts)
- [storage](./src/storage.ts)