Swap arguments for fixture (#215)

Co-authored-by: Piotr Szlachciak <[email protected]>

Author: rzadp

docs/source/fixtures.rst

@@ -14,7 +14,7 @@ Example:
   import BasicTokenMock from './build/BasicTokenMock';
 
   describe('Fixtures', () => {
-    async function fixture(provider, [wallet, other]) {
+    async function fixture([wallet, other], provider) {
       const token = await deployContract(wallet, BasicTokenMock, [
         wallet.address, 1000
       ]);
@@ -34,16 +34,16 @@ Example:
   });
 
 
-Fixtures receive a provider and an array of wallets as an argument. By default, the provider is obtained by calling `createMockProvider` and the wallets by `getWallets`. You can, however, override those by using a custom fixture loader.
+Fixtures receive a provider and an array of wallets as an argument. By default, the wallets are obtained by calling `getWallets` and the provider by `createMockProvider`. You can, however, override those by using a custom fixture loader.
 
 .. code-block:: ts
 
   import {createFixtureLoader} from 'ethereum-waffle';
 
-  const loadFixture = createFixtureLoader(myProvider, myWallets);
+  const loadFixture = createFixtureLoader(myWallets, myProvider);
 
   // later in tests
-  await loadFixture((myProvider, myWallets) => {
+  await loadFixture((myWallets, myProvider) => {
     // fixture implementation
   });
 

waffle-cli/test/example/fixtures-example.ts

@@ -4,7 +4,7 @@ import {Wallet} from 'ethers';
 import BasicTokenMock from './build/BasicTokenMock.json';
 
 describe('INTEGRATION: Fixtures example', () => {
-  async function fixture(provider: MockProvider, [wallet, other]: Wallet[]) {
+  async function fixture([wallet, other]: Wallet[], provider: MockProvider) {
     const token = await deployContract(wallet, BasicTokenMock, [
       wallet.address, 1000
     ]);

waffle-provider/src/fixtures.ts

@@ -1,7 +1,7 @@
 import {providers, Wallet} from 'ethers';
 import {MockProvider} from './MockProvider';
 
-type Fixture<T> = (provider: MockProvider, wallets: Wallet[]) => Promise<T>;
+type Fixture<T> = (wallets: Wallet[], provider: MockProvider) => Promise<T>;
 interface Snapshot<T> {
   fixture: Fixture<T>;
   data: T;
@@ -12,7 +12,7 @@ interface Snapshot<T> {
 
 export const loadFixture = createFixtureLoader();
 
-export function createFixtureLoader(overrideProvider?: MockProvider, overrideWallets?: Wallet[]) {
+export function createFixtureLoader(overrideWallets?: Wallet[], overrideProvider?: MockProvider) {
   const snapshots: Snapshot<any>[] = [];
 
   return async function load<T>(fixture: Fixture<T>): Promise<T> {
@@ -25,7 +25,7 @@ export function createFixtureLoader(overrideProvider?: MockProvider, overrideWal
       const provider = overrideProvider ?? new MockProvider();
       const wallets = overrideWallets ?? provider.getWallets();
 
-      const data = await fixture(provider, wallets);
+      const data = await fixture(wallets, provider);
       const id = await provider.send('evm_snapshot', []);
 
       snapshots.push({fixture, data, id, provider, wallets});

waffle-provider/test/fixtures.ts

@@ -5,10 +5,7 @@ import {TOKEN_ABI, TOKEN_BYTECODE} from './BasicToken';
 
 describe('Integration: Fixtures', () => {
   describe('correctly restores state', () => {
-    async function tokenFixture(
-      provider: MockProvider,
-      [sender, recipient]: Wallet[]
-    ) {
+    async function tokenFixture([sender, recipient]: Wallet[], provider: MockProvider) {
       const factory = new ContractFactory(TOKEN_ABI, TOKEN_BYTECODE, sender);
       return {
         contract: await factory.deploy(1_000),
@@ -49,8 +46,8 @@ describe('Integration: Fixtures', () => {
 
   it('allow for restoring blockchain state', async () => {
     const fixture = async (
-      provider: MockProvider,
-      [wallet, other]: Wallet[]
+      [wallet, other]: Wallet[],
+      provider: MockProvider
     ) => ({wallet, other, provider});
 
     const {wallet, other, provider} = await loadFixture(fixture);
@@ -70,12 +67,12 @@ describe('Integration: Fixtures', () => {
   });
 
   describe('allow for multiple uses of different fixtures', () => {
-    async function sendAB(provider: MockProvider, [a, b]: Wallet[]) {
+    async function sendAB([a, b]: Wallet[], provider: MockProvider) {
       await send(a, b);
       return {a, b};
     }
 
-    async function sendBA(provider: MockProvider, [a, b]: Wallet[]) {
+    async function sendBA([a, b]: Wallet[], provider: MockProvider) {
       await send(b, a);
       return {a, b};
     }
@@ -116,8 +113,8 @@ describe('Integration: Fixtures', () => {
   });
 
   it('run on isolated chains', async () => {
-    const fixtureA = async (provider: MockProvider) => provider;
-    const fixtureB = async (provider: MockProvider) => provider;
+    const fixtureA = async (_: Wallet[], provider: MockProvider) => (provider);
+    const fixtureB = async (_: Wallet[], provider: MockProvider) => (provider);
 
     const providerA1 = await loadFixture(fixtureA);
     const providerA2 = await loadFixture(fixtureA);
@@ -136,11 +133,8 @@ describe('Integration: Fixtures', () => {
     let receivedProvider: any;
     let receivedWallets: any;
 
-    const customLoadFixture = createFixtureLoader(
-      customProvider,
-      customWallets
-    );
-    await customLoadFixture(async (provider, wallets) => {
+    const customLoadFixture = createFixtureLoader(customWallets, customProvider);
+    await customLoadFixture(async (wallets, provider) => {
       receivedProvider = provider;
       receivedWallets = wallets;
     });