Debugging Mocha Unit Tests in Visual Studio Code

To make it runnable directly from VS Code you could add a task to tasks.json:
{ “version”: “0.1.0”, “command”: “npm”, “isShellCommand”: true, “tasks”: [ {“taskName”: “test”, “isTestCommand”: true, “showOutput”: “always” }] }
(Setting “isTestCommand”: true makes it running by just pressing Shift+Ctrl+T.)

But for that you need to make sure you don’t have other custom commands specified other than “npm” (support for multiple custom commands is also a requested feature).

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Thanks for the tip! I’ll have to give that a try.

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To make it running directly from the VS Code you can add a custom “npm test” task to your tasks.json file: https://code.visualstudio.com/Docs/editor/tasks
Setting “isTestCommand” to true would make it running via simply pressing Shift+Ctrl+T.
Although, for that you need to make sure that you don’t have other custom tasks other than “npm” (support for multiple custom commands is also a requested feature).

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this no longer works 😦 as vs code now requires the “program” attribute in the configuration

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I’ll have to update this blog post to demonstrate the correct approach with VS Code 0.10.0+. You’ll want your launch.json file to look like this:
{ "version": "0.2.0", "configurations": [ { "request": "launch", "name": "Debug Mocha Test", "type": "node", // Notice, we bypass the launcher and start the test runner directly "program": "node_modules/mocha/bin/_mocha", "stopOnEntry": true, // run the tests in the test folder "args": ["test"], "cwd": ".", "runtimeExecutable": null, "env": { } } ] }
Now, you can launch that “Debug Mocha Tests” debug configuration from the Debug tab. With this approach, there’s no need to attach to the running process.

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You can automate the use of this even more by setting the “preLaunchTask” on the attach to run the tests:

(have an npm task “test.debug” that has –debug-brk 15429 as a parameter to the test command)

here is the task:
{
“taskName”: “test.debug”,
// Don’t run on Shift+Ctrl+B
“isBuildCommand”: false,
// Run on Ctrl+T
“isTestCommand”: true,
“showOutput”: “always”,
“args”: [
“test.debug”
]
}

here is the launch:
{
“name”: “Run unit tests”,
// Type of configuration.
“type”: “node”,
“request”: “attach”,
“port”: 15429,
“preLaunchTask”: “test.debug”
}

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I want to debug jasmine test cases which are placed in StockSpec.js . Now in launch.json file i have
“program”: “spec/StockSpec.js”, (rest config is as default)
on debugging, I get “describe not defined” as error.
If i change
“program”: “gulpfile.js”,
debugger would blur out step in, step out etc options.
I’m using gulp which contain task to run karma.conf.js file which run my StockSpec.js file through command line. But I want to use debug feature of VS Code like you did. What am I missing 😦

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Thank You!! makes for such a nice testing env!

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“Debugger listening on ws://127.0.0.1:36428/158794f8-e9f1-47e1-ae8b-72da0b9aec4c
Warning: Could not find any test files matching pattern: test.js
No test files found
Debugger attached.
Waiting for the debugger to disconnect…
Warning: Could not find any test files matching pattern: test.js
No test files found” .
please help me to answer the cause of this result.,thank you very much.

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excuse,I have alreadysolved .

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	"devDependencies": {
	"mocha": "^2.3.3"
	},
	"scripts": {
	"test": "mocha –debug-brk"
	}

	{
	"version": "0.1.0",
	"configurations": [
	{
	"name": "Debug Mocha Test",
	"type": "node",
	"address": "localhost",
	"port": 5858,
	"sourceMaps": false
	}
	]
	}

Scott Addie