[ruby-core:68566] [Ruby trunk - Feature #10982] Clarify location of NoMethod error

Issue #10982 has been updated by Parker M.


This new syntax is a pretty sizable divergence from traditional Ruby error reporting. At the moment, errors generally (always?) have an accompanying stack trace:

```text
~$ ruby errors.rb
errors.rb:2:in `<main>': undefined method `call' for nil:NilClass (NoMethodError)
```

It indicates the line, but excludes the column. It's uniform for all errors, so users seeing these stack traces know in what file, what line, and what method (the binding?) the error occurred. If the proposed format were implemented, would it only be for NoMethodError's, or would it apply to ArgumentError's or TypeError's, and so on?

Would the column number suffice? So your example would yield:

```text
irb:1:16:in `<main>': undefined method `call' for nil:NilClass (NoMethodError)
```

You'd know that line 1 at column 16 caused the error.

----------------------------------------
Feature #10982: Clarify location of NoMethod error
https://bugs.ruby-lang.org/issues/10982#change-51880

* Author: Richard Schneeman
* Status: Open
* Priority: Normal
* Assignee: 
----------------------------------------
In Ruby, the error `NoMethodError` on happens frequently, especially when it occurs on `nil`. This error can be confusing to beginners since, many of them think there is a problem with the method instead of the receiver. This error can be confusing to advanced developers when there are multiple method calls in the on the same line. In this example it is unclear if `foo` or `bar` returned `nil`:

```
foo.call && bar.call
NoMethodError: undefined method `call' for nil:NilClass
```

I would like to make this a better error message and to indicate where the exception occurs.

```
@foo.call && @bar.call
                 ^----
NoMethodError: The method `call` is undefined on receiver nil:NilClass
```

Now it is more clear that the `@bar` is currently `nil` and that is the source of the error. I believe exposing this information will help developers of all abilities. 




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