[ruby-core:120103] [Ruby master Bug#20918] Prism error indicates line number of `-e` that does not exist

["tenderlovemaking (Aaron Patterson) via ruby-core" <ruby-core@ml.ruby-lang.org>]

Issue #20918 has been updated by tenderlovemaking (Aaron Patterson).


kddnewton (Kevin Newton) wrote in #note-3:
> I looked into this this morning, it looks like ruby.c is automatically concatenating a \n onto the -e script here: https://github.com/ruby/ruby/blob/f43585b02c3634ab9a4e54049b08e04ab1a640fd/ruby.c#L1303. Is this desired behavior?

I'm not sure if it matters.  If you have a script with one line (that has a newline), Prism will report line 2 as the error.

```
[aaron@tc-lan-adapter ~/g/ruby (master)]$ cat x.rb
foo(
[aaron@tc-lan-adapter ~/g/ruby (master)]$ od -c x.rb
0000000    f   o   o   (  \n                                            
0000005
[aaron@tc-lan-adapter ~/g/ruby (master)]$ wc -l x.rb
       1 x.rb
[aaron@tc-lan-adapter ~/g/ruby (master)]$ ./miniruby x.rb
x.rb: x.rb:2: syntax error found (SyntaxError)
  1 | foo(
> 2 | 
    | ^ unexpected end-of-input; expected a `)` to close the arguments

[aaron@tc-lan-adapter ~/g/ruby (master)]$ 
```

It's fine for newlines to appear in method parameters as well as blocks, so Prism considers the EOF token to be the "error token".  Indeed EOF "occurs" on line 2 (since it's after the newline), but since nobody writes EOF in to their files, I think we should consider the error to have occurred at the newline preceding EOF.

One more example:

```
[aaron@tc-lan-adapter ~/g/ruby (master)]$ cat x.rb
foo(




[aaron@tc-lan-adapter ~/g/ruby (master)]$ wc -l x.rb
       5 x.rb
[aaron@tc-lan-adapter ~/g/ruby (master)]$ od -c x.rb
0000000    f   o   o   (  \n  \n  \n  \n  \n                            
0000011
[aaron@tc-lan-adapter ~/g/ruby (master)]$ ./miniruby x.rb
x.rb: x.rb:6: syntax error found (SyntaxError)
  4 | 
  5 | 
> 6 | 
    | ^ unexpected end-of-input; expected a `)` to close the arguments

[aaron@tc-lan-adapter ~/g/ruby (master)]$
```

Most tools agree the above file only has 5 lines in it, but Prism reports the error on line 6.  IMO errors should only occur on lines that exist.

----------------------------------------
Bug #20918: Prism error indicates line number of `-e` that does not exist
https://bugs.ruby-lang.org/issues/20918#change-110851

* Author: mame (Yusuke Endoh)
* Status: Assigned
* Assignee: prism
* Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN
----------------------------------------
```
$ ruby -e 'foo('
-e: -e:2: syntax error found (SyntaxError)
  1 | foo(
> 2 |
    | ^ unexpected end-of-input; expected a `)` to close the arguments
```

It says `-e:2`, but there is no line 2 in `-e 'foo('`.

`eval("foo(")` reports line 1, so I guess this issue is only for `-e`.



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