feat(shell): run shell command conditionally

[Clumsy-Coder]

what

• Run shell command conditionally (optional)
• Update README docs

how

• the shell directive will check if the 'if' property is available.
  • If it is, it will run the command in 'if' property.
  • If the command results in a return 0 code or 'true', then the 'command' property will run.
  • If the condition to run the command is a non 0 code or 'false', the shell command won't run
• dotbot config example:

- shell:
    - command: echo "this is running on a MacOS"
      if: uname -s | grep -i "Darwin"

• running shell command regardless

- shell:
    - command: echo "This should run regardless"

• dotbot config example: skipping command if false

- shell:
    - command: echo "This command should be skipped"
      if: false

why

• can run the shell command conditionally
• can use multiple dotbot configs to run different OS
  • Ex: incorporating it in https://github.com/ecarlson94/dotbot-template

where

• file changed in ./dotbot/plugins/shell.py

usage

Create dotbot config

- shell:
    - command: echo "this is running on a MacOS"
      if: uname -s | grep -i "Darwin"

- shell:
    - command: echo "This command should be skipped"
      if: false

- shell:
    - command: apt update && apt upgrade -y
      if: lsb_release -i | grep -io 'debian'
      description: Update APT package repository

    - command: dnf update -y
      if: lsb_release -i | grep -io 'fedora'
      description: Update DNF package repository

NOTE

• The reason to wrap the if command in string, is to prevent Python from interpreting it.
  • str(item["if"]),
  • https://github.com/Clumsy-Coder/dotbot/blob/25ef5d5a5fed1e2f95e57115dfdbc8ba67cfc93f/dotbot/plugins/shell.py#L52
  • Try it without wrapping it in strings
    • https://github.com/Clumsy-Coder/dotbot/blob/974156ccdecee05eb9544b0b21cc0351428ddd43/dotbot/plugins/shell.py#L51-L57

    • run_if_result = dotbot.util.shell_command(
          item["if"],
          cwd=self._context.base_directory(),
          enable_stdin=False,
          enable_stdout=False,
          enable_stderr=stderr,
      )

    • Fails to run because error was thrown

      - shell:
          - command: echo "This command should be skipped"
            if: false

    • Works if wrapping false in strings

      - shell:
          - command: echo "This command should be skipped"
            if: "false"

[Clumsy-Coder]

Pull Request connected to issue #312

[Clumsy-Coder]

I tested it as much as I can.

This is first time working in Python code.

So, if issue surfaces, let me know

[wonderbeyond]

Hi, I just made the dotbot-if plugin, and found it's sharing the similar idea with this PR.