## Remix Tests
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[](https://github.com/ethereum/remix-project/tree/master/libs/remix-tests)
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`@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 ](https://remix-ide.readthedocs.io/en/latest/unittesting.html ).
### 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 ](tests/examples_0 ).
#### 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 ](tests/various_sender/sender_and_value_test.sol ).
#### 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 ](tests/various_sender/sender_and_value_test.sol ) 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` :
```Javascript
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:
```Javascript
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
```
:point_right: remix-test can also be used for continuous integration testing. See example [Su Squares contract ](https://github.com/su-squares/ethereum-contract/tree/e542f37d4f8f6c7b07d90a6554424268384a4186 ) and [Travis build ](https://travis-ci.org/su-squares/ethereum-contract/builds/446186067 )
#### As a Library for development
Import library:
```Javascript
const remixTests = require('@remix-project/remix-tests');
```
Run a single test object:
```Javascript
remixTests.runTest (testName: string, testObject: any, contractDetails: CompiledContract, fileAST: AstNode, opts: Options, testCallback: TestCbInterface, resultsCallback: ResultCbInterface)
```
< em > Params:-< / em >
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:
```Javascript
remixTests.runTestSources(contractSources: SrcIfc, versionUrl: string, usingWorker: boolean, testCallback: Function, resultCallback: Function, finalCallback: any, importFileCb: Function, opts: Options);
```
< em > Params:-< / em >
1. `contractSources` - Contract sources
2. `compilerConfig` - Custom compiler configuration
* `currentCompilerUrl: URL to load compiler from`
* `evmVersion: EVM name`
* `optimize: set true to enable optimization`
* `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 ](src/types.ts ).
### 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 guidelines [here ](https://github.com/ethereum/remix-project/blob/master/CONTRIBUTING.md ). Reach us in [Gitter ](https://gitter.im/ethereum/remix ) in case of any queries.
### License
MIT © 2018-21 Remix Team
