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From: "pawurb (Pawel Urbanek) via ruby-core" <ruby-core@ml.ruby-lang.org>
To: ruby-core@ml.ruby-lang.org
Cc: "pawurb (Pawel Urbanek)" <noreply@ruby-lang.org>
Subject: [ruby-core:120430] [Ruby master Feature#20987] Add dbg - minimal debugging helper
Date: Fri, 27 Dec 2024 11:50:02 +0000 (UTC)	[thread overview]
Message-ID: <redmine.journal-111209.20241227115001.55446@ruby-lang.org> (raw)
In-Reply-To: <redmine.issue-20987.20241226234002.55446@ruby-lang.org>

Issue #20987 has been updated by pawurb (Pawel Urbanek).


Hi. It's my first time contributing here, so I'm sorry in advance if I've mixed something up.

I’m author of [dbg-rb gem](https://github.com/pawurb/dbg-rb). `dbg` method is inspired by Rust where it's [built-in into std-lib](https://doc.rust-lang.org/std/macro.dbg.html). AFAIK in Ruby there's no simple mechanism to puts debug values together with caller info without using external dependencies. What’s more frustrating is that while `p nil` outputs `nil` to the std, `puts nil` prints a blank line, sometimes making debugging sessions confusing.

I would like to propose adding a minimal dbg helper method to stdlib:

```ruby
dbg("Hello world", [1, 2, 3])
# => [dir/file.rb:12] "Hello world"
# => [dir/file.rb:12] [1, 2, 3]
```

`dbg` will produce verbose output together with informative file name and LOC info. I think that such built-in feature would be useful for many Ruby devs.

My gem uses external dependencies, but I've came up with this barebones implementation:

```ruby
def dbg(*msgs)
  loc = caller_locations.first
  file = if (path = loc.absolute_path)
        path.split("/").last(2).join("/")
      else
        loc.label
      end
  line = loc.lineno

  src = "[#{file}:#{line}]"

  msgs.each do |msg|
    puts "#{src} #{msg.inspect}"
  end
  nil
end
```

----------------------------------------
Feature #20987: Add dbg - minimal debugging helper
https://bugs.ruby-lang.org/issues/20987#change-111209

* Author: pawurb (Pawel Urbanek)
* Status: Open
----------------------------------------
Hi. It's my first time contributing here, so I'm sorry in advance if I've mixed something up.

I’m author of https://github.com/pawurb/dbg-rb gem. `dbg` method is inspired by Rust where it's built-in into std-lib (https://doc.rust-lang.org/std/macro.dbg.html). AFAIK in Ruby there's no simple mechanism to puts debug values together with caller info without using external dependencies. What’s more frustrating is that while `p nil` outputs `nil` to the std, `puts nil` prints a blank line, sometimes making debugging sessions confusing.

I would like to propose adding a minimal `dbg` helper method to stdlib:

```
dbg("Hello world", [1, 2, 3])
# => [dir/file.rb:12] "Hello world"
# => [dir/file.rb:12] [1, 2, 3]
```

`dbg` will produce verbose output together with informative file name and LOC info. I think that such built-in feature would be useful for many Ruby devs.

My gem uses external dependencies, but I've came up with this barebones implementation:

```
def dbg(*msgs)
  loc = caller_locations.first.to_s
  matching_loc = loc.match(/.+(rb)\:\d+\:(in)\s/)
  src = if matching_loc.nil?
      loc
    else
      matching_loc[0][0..-5]
    end
  file, line = src.split(":")
  file = file.split("/").last(2).join("/")
  src = "[#{file}:#{line}]"

  msgs.each do |msg|
    puts "#{src} #{msg.inspect}"
  end
  nil
end
```


---Files--------------------------------
Screenshot 2024-12-27 at 00.00.23.png (81.5 KB)


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  reply	other threads:[~2024-12-27 11:50 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-12-26 23:40 [ruby-core:120428] " pawurb (Pawel Urbanek) via ruby-core
2024-12-27 11:50 ` pawurb (Pawel Urbanek) via ruby-core [this message]
2024-12-27 19:59 ` [ruby-core:120433] " mame (Yusuke Endoh) via ruby-core
2024-12-27 21:15 ` [ruby-core:120434] " pawurb (Pawel Urbanek) via ruby-core
2025-01-09 11:26 ` [ruby-core:120567] " mame (Yusuke Endoh) via ruby-core

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