remix-project/libs/remix-tests/README.md

Remix Tests

@remix-project/remix-tests is a tool to test Solidity smart contracts. It works underneath Remix IDE "Solidity Unit Testing" plugin which is used to write and run test cases for a contract. Tests are written in Solidity itself. @remix-project/remix-tests can be used as CLI and a library too.

To know more about Remix IDE Solidity Unit Testing Plugin, visit Remix IDE official documentation.

Installation

• As a dev dependency:

yarn add --dev @remix-project/remix-tests

• As a global NPM module to use as CLI:

yarn global add @remix-project/remix-tests

To confirm installation, run:

$ remix-tests --version
0.1.36

Version should be same as on NPM.

Test structure

@remix-project/remix-tests provides and injects a built-in assert library for testing purpose.

Assert library

Available functions	Supported types
Assert.ok()	bool
Assert.equal()	uint, int, bool, address, bytes32, string
Assert.notEqual()	uint, int, bool, address, bytes32, string
Assert.greaterThan()	uint, int
Assert.lesserThan()	uint, int

Examples to understand the use of assert library methods can be found here in tests.

Available special functions:

Apart from above, library provides some special functions as:

• beforeEach() - runs before each test
• beforeAll() - runs before all tests
• afterEach() - runs after each test
• afterAll() - runs after all tests

Example to understand the use of special methods can be found here in tests.

Use a different sender msg.sender

It is quite common that a contract need to be tested in different situation. Especially being able to set before hand the sender account (msg.sender) used for a specific tests suite enable quite a lot a new test use cases. please checkout this test contract for an example. Note that TestsAccounts is filled with all the accounts available in web3.eth.accounts().

How to use

As command line interface

One can see all available option for remix-tests using --help command.

$ remix-tests --help           
Usage: remix-tests [options] [command]

Options:
  -V, --version            output the version number
  -c, --compiler <string>  set compiler version (e.g: 0.6.1, 0.7.1 etc)
  -e, --evm <string>       set EVM version (e.g: petersburg, istanbul etc)
  -o, --optimize <bool>    enable/disable optimization
  -r, --runs <number>      set runs (e.g: 150, 250 etc)
  -v, --verbose <level>    set verbosity level (0 to 5)
  -h, --help               output usage information

Commands:
  version                  output the version number
  help                     output usage information

Along with the shown options, you need to provide a file or directory path.

• To run all test files inside examples directory

$ remix-tests examples/

• To run single test file named simple_storage_test.sol inside examples directory

$ remix-tests examples/simple_storage_test.sol

NOTE: remix-tests will assume that name of tests file ends with "_test.sol". e.g simple_storage_test.sol

Example: Consider for a simple storage contract named simple_storage.sol:

pragma solidity >=0.4.22 <=0.8.0;

contract SimpleStorage {
  uint public storedData;

  constructor() public {
    storedData = 100;
  }

  function set(uint x) public {
    storedData = x;
  }

  function get() public view returns (uint retVal) {
    return storedData;
  }
}

test file simple_storage_test.sol can be as:

pragma solidity >=0.4.22 <=0.8.0;
import "remix_tests.sol"; // injected by remix-tests
import "./simple_storage.sol";

contract MyTest {
  SimpleStorage foo;

  function beforeAll() public {
    foo = new SimpleStorage();
  }

  function initialValueShouldBe100() public returns (bool) {
    return Assert.equal(foo.get(), 100, "initial value is not correct");
  }

  function initialValueShouldNotBe200() public returns (bool) {
    return Assert.notEqual(foo.get(), 200, "initial value is not correct");
  }

  function shouldTriggerOneFail() public {
    Assert.equal(uint(1), uint(2), "uint test 1 fails");
    Assert.notEqual(uint(1), uint(2), "uint test 2 passes");
  }

  function shouldTriggerOnePass() public {
    Assert.equal(uint(1), uint(1), "uint test 3 passes");
  }
}

Running simple_storage_test.sol file will output as:

$ remix-tests simple_storage_test.sol

	👁	:: Running remix-tests - Unit testing for solidity ::	👁

'creation of library remix_tests.sol:Assert pending...'

	◼  MyTest
	✓  Initial value should be100
	✓  Initial value should not be200
	✘  Should trigger one fail
	✓  Should trigger one pass


3 passing (0.282s)
1 failing

  1) MyTest: Should trigger one fail

	 error: uint test 1 fails
	 expected value to be equal to: 2
	 returned: 1

Most of the remix-tests options are there to define a custom compiler context. With an extended custom compiler context, execution of above test file will go as:

$ remix-tests --compiler 0.7.4 --evm istanbul --optimize true --runs 300 simple_storage_test.sol

	👁	:: Running remix-tests - Unit testing for solidity ::	👁

[14:03:18] info: Compiler version set to 0.7.4. Latest version is 0.8.0
[14:03:18] info: EVM set to istanbul
[14:03:18] info: Optimization is enabled
[14:03:18] info: Runs set to 300
Loading remote solc version v0.7.4+commit.3f05b770 ...
'creation of library remix_tests.sol:Assert pending...'

	◼  MyTest
	✓  Initial value should be100
	✓  Initial value should not be200
	✘  Should trigger one fail
	✓  Should trigger one pass


3 passing (0.316s)
1 failing

  1) MyTest: Should trigger one fail

	 error: uint test 1 fails
	 expected value to be equal to: 2
	 returned: 1

👉 remix-test can also be used for continuous integration testing. See example Su Squares contract and Travis build

As a Library for development

Import library:

const remixTests = require('@remix-project/remix-tests');

Run a single test object:

remixTests.runTest (testName: string, testObject: any, contractDetails: CompiledContract, fileAST: AstNode, opts: Options, testCallback: TestCbInterface, resultsCallback: ResultCbInterface)

Params:-

1. testName - Name of the test
2. testObject - Web3 1.0 contract instance of the test
3. contractDetails - Contract details
4. fileAST - AST of test file
5. opts - Custom options
6. testCallback(object) - Called each time there is a test event. 3 possible type of objects:

• { type: 'contract', value: '<TestName>', filename: '<test_filename.sol>' }
• { type: 'testPass', value: '<name of testing function>', time: <time taken>, context: '<TestName>'}
• { type: 'testFailure', value: '<name of testing function>', time: <time taken>, context: '<TestName>', errMsg: '<message in the Assert>' }

7. resultsCallback(object) - Callback with test results

• passingNum - number of passing tests
• failureNum - number of failing tests
• timePassed - time it took for all the tests to run (in seconds)

Running a set of tests given the sourcecode:

remixTests.runTestSources(contractSources: SrcIfc, versionUrl: string, usingWorker: boolean, testCallback: Function, resultCallback: Function, finalCallback: any, importFileCb: Function, opts: Options);

Params:-

1. contractSources - Contract sources
2. compilerConfig - Custom compiler configuration

• currentCompilerUrl: URL to load compiler from
• evmVersion: EVM name
• optimize: set true to enable optimizartion
• usingWorker?: set true to load compiler using worker
• runs: number of contract runs

3. testCallback(object) - Called each time there is a test event. 3 possible type of objects:

• { type: 'contract', value: '<TestName>', filename: '<test_filename.sol>' }
• { type: 'testPass', value: '<name of testing function>', time: <time taken>, context: '<TestName>'}
• { type: 'testFailure', value: '<name of testing function>', time: <time taken>, context: '<TestName>', errMsg: '<message in the Assert>' }

4. resultCallback(err, object) - Callback with test results

• passingNum - number of passing tests
• failureNum - number of failing tests
• timePassed - time it took for all the tests to run (in seconds)

5. finalCallback(err) - called when all tests finish running.
6. importCb(url, cb) - Callback to resolve imported files
7. opts - Custom options

For more details, see parameters' type definitions here.

Contribute

Please feel free to open an issue or a pull request.

In case you want to add a code, do have a look to our contribution guidelnes here. Reach us in Gitter in case of any queries.

License

MIT © 2018-21 Remix Team