debugging-with-vscode.md

Debugging tests with Visual Studio Code

Translations: Français

You can debug your tests using Visual Studio Code.

Creating a launch configuration

1. Open a workspace for your project.
2. In the sidebar click the Debug handle.
3. Create a launch.json file.
4. Select the Node.js environment.
5. Add following to the configurations array and save changes:

{
  "type": "node",
  "request": "launch",
  "name": "Debug AVA test file",
  "runtimeExecutable": "${workspaceFolder}/node_modules/.bin/ava",
  "runtimeArgs": [
    "debug",
    "--break",
    "${file}"
  ],
  "port": 9229,
  "outputCapture": "std",
  "skipFiles": [
    "<node_internals>/**/*.js"
  ]
}

Using the debugger

Open the file(s) you want to debug. You can set breakpoints or use the debugger keyword.

Now, with a test file open, from the Debug menu run the Debug AVA test file configuration.

Debugging precompiled tests

If you compile your test files into a different directory, and run the tests from that directory, the above configuration won't work.

Assuming the names of your test files are unique you could try the following configuration instead. This assumes the compile output is written to the build directory. Adjust as appropriate:

{
  "type": "node",
  "request": "launch",
  "name": "Debug AVA test file",
  "runtimeExecutable": "${workspaceFolder}/node_modules/.bin/ava",
  "runtimeArgs": [
    "debug",
    "--break",
    "build/**/${fileBasenameNoExtension}.*"
  ],
  "port": 9229,
  "outputCapture": "std",
  "skipFiles": [
    "<node_internals>/**/*.js"
  ]
}

Serial debugging

By default AVA runs tests concurrently. This may complicate debugging. Add a configuration with the --serial argument so AVA runs only one test at a time:

{
  "type": "node",
  "request": "launch",
  "name": "Debug AVA test file",
  "runtimeExecutable": "${workspaceFolder}/node_modules/.bin/ava",
  "runtimeArgs": [
    "debug",
    "--break",
    "--serial",
    "${file}"
  ],
  "port": 9229,
  "outputCapture": "std",
  "skipFiles": [
    "<node_internals>/**/*.js"
  ]
}

Note that, if your tests aren't properly isolated, certain test failures may not appear when running the tests serially.