Bash-it Development

This page summarizes a couple of rules to keep in mind when developing features or making changes in Bash-it.

Testing

Make sure to read the testing docs.

Debugging and Logging

General Logging

While developing feature or making changes in general, you can log error/warning/debug using _log_error _log_warning and _log_debug. This will help you solve problems quicker and also propagate important notes to other users of Bash-it. You can see the logs by using bash-it doctor command to reload and see the logs. Alternatively, you can set BASH_IT_LOG_LEVEL to BASH_IT_LOG_LEVEL_ERROR, BASH_IT_LOG_LEVEL_WARNING or BASH_IT_LOG_LEVEL_ALL.

Log Prefix/Context

You can define BASH_IT_LOG_PREFIX in your files in order to a have a constant prefix before your logs. Note that we prefer to uses “tags” based logging, i.e plugins: git: DEBUG: Loading git plugin.

Load Order

General Load Order

The main bash_it.sh script loads the frameworks individual components in the following order:

  • vendor/github.com/erichs/composure/composure.sh

  • lib/log.bash

  • vendor/init.d/*.bash

  • Files in lib with the exception of appearance.bash - this means that log.bash is loaded again here (possible improvement?)

  • Enabled aliases

  • Enabled plugins

  • Enabled completions

  • themes/colors.theme.bash

  • themes/base.theme.bash

  • lib/appearance.bash, which loads the selected theme

  • Custom aliases

  • Custom plugins

  • Custom completions

  • Additional custom files from either $BASH_IT/custom or $BASH_IT_CUSTOM

This order is subject to change.

Individual Component Load Order

For aliases, plugins and completions, the following rules are applied that influence the load order:

  • There is a global enabled directory, which the enabled components are linked into. Enabled plugins are symlinked from $BASH_IT/plugins/available to $BASH_IT/enabled for example. All component types are linked into the same common $BASH_IT/enabled directory.

  • Within the common enabled directories, the files are loaded in alphabetical order, which is based on the item’s load priority (see next item).

  • When enabling a component, a load priority is assigned to the file. The following default priorities are used:

    • Aliases: 150

    • Plugins: 250

    • Completions: 350

  • When symlinking a component into the enabled directory, the load priority is used as a prefix for the linked name, separated with three dashes from the name of the component. The node.plugin.bash would be symlinked to 250---node.plugin.bash for example.

  • Each file can override the default load priority by specifying a new value. To do this, the file needs to include a comment in the following form. This example would cause the node.plugin.bash (if included in that file) to be linked to 225---node.plugin.bash:

    # BASH_IT_LOAD_PRIORITY: 225

Having the order based on a numeric priority in a common directory allows for more flexibility. While in general, aliases are loaded first (since their default priority is 150), it’s possible to load some aliases after the plugins, or some plugins after completions by setting the items’ load priority. This is more flexible than a fixed type-based order or a strict alphabetical order based on name.

These items are subject to change. When making changes to the internal functionality, this page needs to be updated as well.

Working with vendored libs

Vendored libs are external libraries, meaning source code not maintained by Bash-it developers. They are git subtrees curated in the vendor/ folder. To ease the work with git vendored libs as subtrees we use the git-vendor tool. The original repo for git vendor is unmaintained so for now we are recommending Tyrben’s fork.

For more information on git vendor there are a short usage description in the repositories README file and a website for the original repository has a manual page which is also included in both repositories.

To support a flexible loading of external libraries, a file unique to the vendored library must be placed in vendor/init.d/ with the .bash extension.

Rebasing a feature branch with an added/updated vendored library

If your feature branch with a newly added/updated vendored lib has fallen behind master you might need to rebase it before creating a PR. However rebasing with dangling subtree commits can cause problems. The following rebase strategy will pause the rebase at the point where you added a subtree and let you add it again before continuing the rebasing.

[feature/branch] $ git rebase --rebase-merges --strategy subtree master
fatal: refusing to merge unrelated histories
Could not apply 0d6a56b... Add-preexec-from-https-github-com-rcaloras-bash-preexec-0-4-1- # Add "preexec" from "https://github.com/rcaloras/bash-preexec@0.4.1"
[feature/branch] $ git vendor add preexec https://github.com/rcaloras/bash-preexec 0.4.1
...
[feature/branch] $ git rebase --continue

If rebasing makes you a little uneasy (as it probably should). You can always test in another branch.

[feater/branch] $ git checkout -b feature/branch-test-rebase
[feater/branch-test-rebase] $ git rebase --rebase-merges --strategy subtree master
...

Afterwards you can make sure the rebase was successful by running git vendor list to see if your library is still recognized as a vendored lib

[feature/branch] $ git vendor list
preexec@0.4.1:
    name:   preexec
    dir:    vendor/github.com/rcaloras/bash-preexec
    repo:   https://github.com/rcaloras/bash-preexec
    ref:    0.4.1
    commit: 8fe585c5cf377a3830b895fe26e694b020d8db1a
[feature/branch] $

Plugin Disable Callbacks

Plugins can define a function that will be called when the plugin is being disabled. The callback name should be {PLUGIN_NAME}_on_disable, you can see gitstatus for usage example.

Library Finalization Callback

Specifically for Bash-it library code, e.g. in the lib subdirectory, a hook is available to run some code at the very end of the main loader script after all other code has been loaded. For example, lib/theme uses _bash_it_library_finalize_hook+=(‘_bash_it_appearance_scm_init’) to add a function to be called after all plugins have been loaded.

Using the pre-commit hook

Note the file .pre-commit-config.yaml at the top of the repo. This file configures the behavior of the a pre-commit hook based on the Pre-Commit framework. Please see the site about installing it (with pip, brew or other tools) then run pre-commit install in the repo’s root to activate the hook. For the full use of the tool, you may need to install also other third-party tools, such as shellcheck and shfmt.

Linting Your Changes

In order to properly lint your changes, you should use our linting script, by simply running ./lint_clean_files.sh. This script iterates over all marked-as-clean files, and runs the pre-commit hook on them.

Please note that most of the files in the project are currently not linted, as we want to make the linting process easier. In order to add your changed/added files to the linting process, please add your files to clean_files.txt. This way lint_clean_files.sh will know to pick them up and lint them.

Thank you for helping clean up Bash-it, and making it a nicer and better project ❤️