Testing your changes

Automated tests

Corda has a suite of tests that any contributing developers must maintain and extend when adding new code.

There are several test suites:

  • Unit tests: These are traditional unit tests that should only test a single code unit, typically a method or class.
  • Integration tests: These tests should test the integration of small numbers of units, preferably with mocked out services.
  • Smoke tests: These are full end to end tests which start a full set of Corda nodes and verify broader behaviour.
  • Other: These include tests such as performance tests, stress tests, etc, and may be in an external repo.

Running the automated tests

These tests are mostly written with JUnit and can be run via gradle:

  • Windows: Run gradlew test integrationTest smokeTest
  • Unix/Mac OSX: Run ./gradlew test integrationTest smokeTest

Before creating a pull request please make sure these pass.

Manual testing

You should manually test anything that would be impacted by your changes. The areas that usually need to be manually tested and when are as follows:

  • Node startup - changes in the node or node:capsule project in both the Kotlin or gradle or the cordformation gradle plugin.
  • Sample project - changes in the samples project. eg; changing the IRS demo means you should manually test the IRS demo.
  • Explorer - changes to the tools/explorer project.
  • Demobench - changes to the tools/demobench project.

How to manually test each of these areas differs and is currently not fully specified. For now the best thing to do is to ensure the program starts, that you can interact with it, and that no exceptions are generated in normal operation.

Running tests in IntelliJ

We recommend editing your IntelliJ preferences so that you use the Gradle runner - this means that the quasar utils plugin will make sure that some flags (like -javaagent - see below) are set for you.

To switch to using the Gradle runner:

  • Navigate to Build, Execution, Deployment -> Build Tools -> Gradle -> Runner (or search for runner)
    • Windows: this is in “Settings”
    • MacOS: this is in “Preferences”
  • Set “Delegate IDE build/run actions to gradle” to true
  • Set “Run test using:” to “Gradle Test Runner”

If you would prefer to use the built in IntelliJ JUnit test runner, you can add some code to your build.gradle file and it will copy your quasar JAR file to the lib directory.


Before creating the IntelliJ run configurations for these unit tests go to Run -> Edit Configurations -> Defaults -> JUnit, add -javaagent:lib/quasar.jar to the VM options, and set Working directory to $PROJECT_DIR$ so that the Quasar instrumentation is correctly configured.

Add the following to your build.gradle file - ideally to a build.gradle that already contains the quasar-utils plugin line:

apply plugin: 'net.corda.plugins.quasar-utils'

task installQuasar(type: Copy) {
    destinationDir rootProject.file("lib")
    from(configurations.quasar) {
        rename 'quasar-core(.*).jar', 'quasar.jar'

and then you can run gradlew installQuasar.