Debugging go in vscode with environment variables

When running tests in vscode you often need environment variables, some of which may have json values.

Option 1: settings.json

Open settings.json and add this at the top level:

"go.testEnvVars": {
  "LOG_LEVEL": "debug",
},

All your tests will now receive this environment variable.

Option 2: launch.json

To start, you need to configure launch.json:

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Launch",
      "type": "go",
      "request": "launch", 
      "mode": "debug",
      "remotePath": "",
      "port": 2345,
      "host": "127.0.0.1",
      "program": "${workspaceFolder}",
      "args": [], 
      "showLog": true
    }
  ]
}

Note that this will try to debug code in your root directory.
If you have subdirs in your project, you will need something like this:

“program”: “${workspaceFolder}/subdir”

Or specify the source file and, optionally, the test function name:

"program": "${workspaceFolder}/subdir/http_test.go",
"args": [
    "-test.run",
    "TestWithHTTP"
]

Now you can add environment variables in launch.json:

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Launch",
      "type": "go",
      "request": "launch", 
      "mode": "debug",
      "remotePath": "",
      "port": 2345,
      "host": "127.0.0.1",
      "${workspaceFolder}/subdir/http_test.go",
      "args": [
          "-test.run",
          "TestWithHTTP"
      ],
      "env": {
        "GCLOUD_PROJECT_ID":"my-project"
      },
      "showLog": true
    }
  ]
}

For more advanced scenarios, for example, requiring json values, you can load an external environment file, like this:

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Launch",
      "type": "go",
      "request": "launch", 
      "mode": "debug",
      "remotePath": "",
      "port": 2345,
      "host": "127.0.0.1",
      "${workspaceFolder}/subdir/http_test.go",
      "args": [
          "-test.run",
          "TestWithHTTP"
      ],
      "envFile": "${workspaceFolder}/.env",
      "showLog": true
    }
  ]
}

Place the .env file in your directory and add more variables like this:

KEY1="TEXT_VAL1"
KEY2='{"key1":val1","key2":"val2"}'

Running Your Tests

Getting VSCode to actually use the environment vars is tricky.
This seems to work:

• Write a test function like this:

• Don’t click “run test” nor “debug test” — these won’t leverage your environment.
• Instead, click the View menu and select Debug (or ctrl+shift+d)
• Select the name of your configuration in the DEBUG drop-down and click the Green “run” arrow — this will run your test in debug mode with the environment that you defined:

You can find some additional information here:

https://github.com/Microsoft/vscode-go/wiki/Debugging-Go-code-using-VS-Code