Write commands

Command generation with alfred --new is limited to simple cases. It is possible to create more complex commands using the library functions.

You can write a command in any python module inside the alfred folder. Just decorate a function with alfred.command.

Write a simple command

The command is the basic element to create a task to be executed.

@alfred.command('lint', help="validate your product using mypy")
def lint():
    alfred.run("mypy src/alfred")

Warning

It’s not run in a shell. Operations like “>” or “>>” are not supported

Warning

On windows, commands like Echo or Copy on Windows are internal commands to the Cmd.exe shell, not executable. They cannot be used from Alfred.

I recommand using print and shutil.copy instead.

Compose a command

Retrieving the executable and using an argument array makes command composition easier. It is possible to add or remove arguments depending on the platform or environment.

alfred/lint.py

import alfred

@alfred.command('lint', help="validate your product using mypy")
def lint():
    mypy = alfred.sh('mypy', "mypy is not installed")
    alfred.run(mypy, ["src/alfred"])

Use optional parameters

It would be great to be able to investigate a failing job and run it in verbose mode without writing a new command.

For example, we want to run the unit tests in verbose mode to get more information about the tests.

alfred/tests.py

import alfred

@alfred.command('test', help="execute unit tests with pytest")
@alfred.option('--verbose', help="run pytest in verbose mode", is_flag=True, default=False)
def test(verbose):
    pytest = alfred.sh('pytest', "pytest is not installed")
    args = [] if not verbose else ['-v']
    args += ['tests']

    alfred.run(pytest, args)

Click Next when you are ready to write your first pipeline !