• Install phpunit.
• Set the config values:

{
    "phpunit.execPath": "path/to/phpunit",
    "phpunit.args": [
        "--configuration", "./phpunit.xml.dist"
    ],
    "phpunit.preferRunClassTestOverQuickPickWindow": false // Default false
}

Run with (Cmd+Shift+P on OSX or Ctrl+Shift+P on Windows and Linux) and execute the PHPUnit Test command.

• Test a function: Place cursor on a function and run.

• Test a class: Place cursor on class name and run.

• Pick test from a list: Place cursor anywhere in class except on class name or on a function and run.

• Test everything according to --configuration: Close editor window and run.

• Test everything in a directory: Open a file in the directory to test and run the PHPUnit Test Directory command.

• Rerun last Test: Run the PHPUnit Rerun last test command. Is also possible set a keybinding to run this command:

{ "key": "cmd+shift+r", "command": "phpunit.RerunLastTest", "when": "editorFocus" }

• execPath is recommended to set in your 'user settings'. Having phpunit in PATH doesn't work (at least on windows 10) =(.
• args is recommended to set in your 'workspace settings'. You can add any phpunit args, check phpunit --help.
• To hook into the debugger (github.com/felixfbecker/vscode-php-debug). Add Key:XDEBUG_CONFIG, Value:idekey=VSCODE to your environment variables. (Tested on Windows 10)