Adding a New File

Here, we register a new example file to the testbench. We want this file to be a simple text file that contains a greeting, to be used in the greet_user task we created earlier.

Creating a Concrete File Implementation

For this, we create a new file type greeting in registry/files/file_greeting.py:

from pathlib import Path
from typing import Optional

from testbench import File


class Greeting(File):
    def __init__(
        self, path: Path, configs: dict, output_dir: Path, name: Optional[str] = None
    ):
        super().__init__(path, "txt", configs, output_dir, name)

As you can see, this class inherits from the File base class, which provides some basic functionality for the file, including the parse method, which is used to read the file and extract the relevant information. In this case, we do not need to implement the parse method, since it already is a basic implementation that replaces placeholders in the file with the actual values from the configs dictionary.

Testing the Tool

We then register the new file type in the config/registry/files.yml file by adding the following entry:

path: registry/files

greeting: Greeting

We then add this file to the greet_user task in the config/tasks/greet_user.yml file:

path: test # Now, we use the test directory as the project path

tools:
  hello:
    name: file
    user: Cedric # We pass the user name as a parameter to the tool

files:
  greeting:
    path: .
    name: greeting.txt
    configs:
      USER_NAME: Cedric # We pass the user name as a configuration to the file

We create a new file test/greeting.txt with the following content:

Hello, USER_NAME!

Since we use the greeting file type, the testbench will automatically read the greeting.txt file and replace the USER_NAME placeholder with the actual user name Cedric. We thus do not need to add any additional steps to the schedule.yml file, since the greeting file type will handle the replacement automatically.

This will then produce the same output as before, but now we also have a files directory in the task output directory that contains the greeting.txt file with the following content:

Hello, Cedric!

This means that the USER_NAME placeholder in the greeting.txt file was replaced with the actual user name Cedric.

As well as greeting.bak, which is a backup of the original file before the replacement was made.

[!NOTE] In the future, the functionality of directly writing to a file will be moved to the File base class, so that all file types can use it. This will make it easier to create new file types that need to write to a file. Also, we should be able to create new files and not relay on existing files, so that we can create files from scratch.

To find out more about how to create and register new tools and tasks, see the new tool documentation.

To find out more about the structure of the testbench, see the structure documentation.