Basic testing

Create a mock provider

To create a mock provider for running your contracts test against it, e.g.:

provider = createMockProvider();

To modify default provider behavior createMockProvider() takes optional Ganache options parameter. It can be object with specified options or absolute path to waffle.json or another config file, e.g.:

provider = createMockProvider({gasLimit: 0x6691b7, gasPrice: 0x77359400});

provider = createMockProvider('./waffle.json');

    "ganacheOptions": {
      "gasLimit": "0x6691b7",
      "gasPrice": "0x77359400"

Get example wallets

Get wallets you can use to sign transactions:

[wallet, walletTo] = getWallets(provider);

You can get up to ten wallets.

Deploy contract

Once you compile your contracts using waffle you can deploy them in your javascript code. It accepts three arguments:
  • wallet to send the deploy transaction
  • contract information (abi and bytecode)
  • contract constructor arguments

Deploy a contract:

import BasicTokenMock from "build/BasicTokenMock.json";

token = await deployContract(wallet, BasicTokenMock, [wallet.address, 1000]);

The contract information can be one of the following formats:

interface StandardContractJSON {
  abi: any;
  evm: {bytecode: {object: any}};

interface SimpleContractJSON {
  abi: any[];
  bytecode: string;


Link a library:

myLibrary = await deployContract(wallet, MyLibrary, []);
link(LibraryConsumer, 'path/to/file/MyLibrary.sol/MyLibrary', myLibrary.address);
libraryConsumer = await deployContract(wallet, LibraryConsumer, []);

Note: Note: As the second parameter of the link function, you need to use a fully qualified name (full path to file, followed by a colon and the contract name).