Motivation

When I joined a new project, I had a lot of trouble finding out where it was defined, full of methods. In order to catch up quickly, I felt that "the ability to quickly investigate and understand" was very important, so I asked senior engineers to summarize it. There are advantages and disadvantages to checking.

For methods defined in the project

1. `git grep -n <method name>`

It is easier to see because it is displayed in color in the terminal than full-text search in the editor.
The line number is added with the -n option, so click the command + path to open it in the editor!
Disadvantages: Character string search. There are quite a lot of hits. If you use "def method name", it will be narrowed down a little.

2. Enter in the search window of Github with a browser and search for "in this repository"

This method has the same result as 1., but the top and bottom lines of the matched part are also displayed together.
Good when you don't want to use an editor
Disadvantages: Character string search. There are quite a lot of hits. It is narrowed down by entering "def method name" and double quotation marks.

3. Use the show-source function of pry-docs

In the Rails console, $ <method name> OR show-source <method name>
Displays from def to end of the definition part!
The path is also displayed, so you can display it in the editor by command + click.
Disadvantage: When you want to check user.method, you have to create a User instance before you can check it, so it is troublesome.

4. Use Pry's "step" feature

When stopped at binding.pry, you can "enter" into that method by running step.
You can also see the processing flow and variable definitions for a deeper understanding.
You can see deep places such as Rails / Gem.
Disadvantages: It is troublesome to set up binding.pry and stop the process.

Pikawaka [Rails] Pry is thoroughly explained!

When defined outside the project such as Gem

1. Search by Dash

Dash is a tool that allows cross-searching of various documents such as plain Ruby, Rails, Gem, and JavaScript.
In addition to the source code, the method is explained so that it is easy to understand.
By adding the extension "Dash" to VS Code, you can jump to Dash search with command + H.
Disadvantage: Sometimes there is no Gem you want to check

2. `bundle show <gem name>`

Since the directory where Gem is installed is displayed, VS Code can be opened in a new window with command + click.
Disadvantages: git and pry cannot be used, so you need to find the method by cross-searching in the editor.

3. Use Pry's "step" feature

Same as for the methods defined in the project.

4. Enter in the search window of Github with a browser and search for "in this repository"

Same as for the methods defined in the project.

Other

1. Use the Rubymine definition source jump

I'm a VS Code user, so I've never used it. However, I feel that Dash can almost cover the definitions in Ruby, Rails, and Gem.
Disadvantages: expensive, slow

2. Use Solargraph, an extension of VS Code

Simply hover your cursor over a Ruby method to see its documentation and usage examples.
There is also a complementary function
Disadvantages: It's painful when using Docker. Solargraph needs to keep its Language server running. You need to launch the Solargrap container and set the Port to VS Code. Reference: How to use solargraph in Docker environment

Finally

I would like to know your "how to check".
If there is another good way, please let me know in the comments m (_ _) m

Method definition location Summary of how to check When defined in the project and Rails / Gem