getappmap / getappmap/appmap-ruby

Proper way of hooking methods named `call`

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#344 2 comments 1 reaction 0 assignees View on GitHub

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bug
Dominant language
Ruby
Stars
101
Forks
13
PR merge metrics
No merged PRs in 30d

Description

It looks that we globally ignore methods named call here.

When we want to hook methods named call in our application Ruby classes (./app or ./lib in our case), is there any proper way to do this?

Currently, I'm working around it with a monkey patch like this:

# lib/appmap/hook.rb
module AppMap
  class Hook
    def trace_end(...)
      ...
      local_path = location.delete_prefix(Dir.pwd + '/')
      is_app = local_path.start_with?('app') || local_path.start_with?('lib')
      next if !is_app && method_id == :call

But I think there must be a better way to do this.

Contributor guide

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start in lib/appmap/hook.rb, especially trace_end and the logic that skips methods named call. Review the linked pull request context to understand why call is globally ignored. Done means application methods named call in app or lib can be hooked without a monkey patch, while the existing exclusions remain intentional.

Written by the indexing model from the issue text.

Assessment

Tech stack
ruby
Domain
tooling
Issue type
Feature
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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