Exploring my Emacs packages - Projectile

Normally I would use C-x C-f (find-file) to open other files in a project. Projectile provides C-c p f (projectile-find-file), which is a very fast alternative.

Ignored files are automatically filtered from the list and it integrates nicely with Helm.

C-c p d works in a similar way for directories and opens them in dired. C-c p b can be used to switch between project buffers.

For most projects I'll have a terminal window open to run tests and compile code. Both of these things can be done using Projectile commands:

• C-c p P – Runs a test command for the current project.
• C-c p c – Runs a compilation command for the current project.

Each command will try to figure out the best function for the current project type. There are currently 30 different project types built-in, covering Rails, Symfony, Django and a bunch of other common platforms.

Project types are assigned by searching for specific files in the project root. For example, finding a Makefile file in the root will set the default compile command to make and the default test command to make test.

Projects can set their compile and test commands using Emacs .dir-locals.el.

• projectile-project-compilation-cmd sets the compilation command
• projectile-project-test-cmd sets the test command
• projectile-project-run-cmd sets the run command
• projectile-project-compilation-dir sets the directory to run compilation commands in.

These will override whatever type Projectile has assigned.

Example: .dir-locals.el for a Common Lisp project

((nil . ((projectile-project-test-cmd . "sbcl --script test.lisp"))))

The .dir-locals.el overrides make it possible to customize projects no matter what language or setup they're using.

Projectile's C-c p t command works most of the time, but a couple of my projects needed to be tweaked slightly to work properly due to the way test files are named and found.

To find the appropriate test file, Projectile strips the current filename of its path and extension, and then checks for a specific prefix or suffix.

For example:

"project/src/module/my_file.rb" will be stripped down to just "my_file". Ruby projects use "_test" as the suffix, meaning Projectile will attempt to open "my_file_test.rb" wherever it is located.

Some of my projects use the same name for source and test files, but stores them in different directories. It may be possible to extend this behaviour, but I'm still looking into that.

projectile-rails can be used to switch between models and views within rails projects.

For none-Rails projects, there are a couple of options, although neither are perfect:

• C-c p a – Switches between files with the same name but a different extension.
• C-c p g – Jumps to the file at the current point. This worked well for projects that explicitly named view templates.

Both of these options are supported and very quick:

• C-c p s g – Runs grep on the entire project
• C-c p o – Runs occur on all open project buffers

C-c p v opens version control for the current project. It automatically works out the best option based on what version control the project is under. For example, projects under git will open magit if installed.

There's no shortcut for renaming files, but being able to quickly open dired for project directories makes the whole process much easier.

C-c p ! runs a shell command in the project root. There's no shortcut to open a terminal .