[ruby-core:116321] [Ruby master Feature#19117] Include the method owner in backtraces, not just the method name

19 Jan 2024

      Issue #19117 has been updated by byroot (Jean Boussier).

I tried the following (contrived) script:

```ruby
class Abstract
  def oops
    yield
  end
end

class Concrete < Abstract
  class << self
    def oops(&block)
      new.oops { 1 + "1" }
    end
  end

  def oops(&block)
    tap do
      super(&block)
    end
  end
end

Concrete.method(:oops).call
```

3.3:

```
test.rb:10:in `+': String can't be coerced into Integer (TypeError)
	from test.rb:10:in `block in oops'
	from test.rb:3:in `oops'
	from test.rb:16:in `block in oops'
	from <internal:kernel>:90:in `tap'
	from test.rb:15:in `oops'
	from test.rb:10:in `oops'
	from test.rb:21:in `call'
	from test.rb:21:in `<main>'
```

Your branch:

```
./test.rb:10:in `Integer#+': String can't be coerced into Integer (TypeError)
	from ./test.rb:10:in `block in Concrete.oops'
	from ./test.rb:3:in `Abstract#oops'
	from ./test.rb:16:in `block in Concrete#oops'
	from <internal:kernel>:90:in `Kernel#tap'
	from ./test.rb:15:in `Concrete#oops'
	from ./test.rb:10:in `Concrete.oops'
	from ./test.rb:21:in `Method#call'
	from ./test.rb:21:in `<main>'
```

I think it very significantly improve the backtrace readability. Things like `call` becoming `Method#call` is really great.

I also love in your example that `toplevel` is displayed as `Object#toplevel`, I think it could help quite a few people realize that defining a method at the top level defines it in `Object`.

----------------------------------------
Feature #19117: Include the method owner in backtraces, not just the method name
https://bugs.ruby-lang.org/issues/19117#change-106347

* Author: byroot (Jean Boussier)
* Status: Open
* Priority: Normal
* Target version: 3.4
----------------------------------------
```
module Foo
  class Bar
    def inspect
      1 + '1'
    end
  end
end

p Foo::Bar.new
```

This code produce the following backtrace:

```
/tmp/foo.rb:4:in `+': String can't be coerced into Integer (TypeError)
	from /tmp/foo.rb:4:in `inspect'
	from /tmp/foo.rb:9:in `p'
	from /tmp/foo.rb:9:in `<main>'
```

This works, but on large codebases and large backtraces the method name isn't always all that revealing, most of the time you need to open many of the locations listed in the backtrace to really understand what is going on.

I propose that we also include the owner name:

```
/tmp/foo.rb:4:in `Integer#+': String can't be coerced into Integer (TypeError)
	from /tmp/foo.rb:4:in `Foo::Bar#inspect'
	from /tmp/foo.rb:9:in `Kernel#p'
	from /tmp/foo.rb:9:in `<main>'
```

I believe that in many case it would allow to much better understand the backtrace without having to jump back and forth between it and the source code.

This is inspired by @ivoanjo 's `backtracie` gem: https://github.com/ivoanjo/backtracie

-- 
https://bugs.ruby-lang.org/

byroot (Jean Boussier)

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