[ruby-core:110119] [Ruby master Bug#19026] Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.

[ruby-core:110119] [Ruby master Bug#19026] Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.

[ioquatix (Samuel Williams)]

Issue #19026 has been reported by ioquatix (Samuel Williams).

----------------------------------------
Bug #19026: Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.
https://bugs.ruby-lang.org/issues/19026

* Author: ioquatix (Samuel Williams)
* Status: Open
* Priority: Normal
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN
----------------------------------------
Introduce the following interface:

```
Coverage.supported?(eval) -> true/false
```

We can also check `lines` `branches` and `methods`?



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

[ruby-core:110120] [Ruby master Bug#19026] Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.

[mame (Yusuke Endoh)]

Issue #19026 has been updated by mame (Yusuke Endoh).


Note: This API does determine if the mode is *available*, not *enabled*. So `Coverage.supported?(:eval)` will always returns `true` in Ruby 3.2 regardless of whether `Coverage.start(eval: true)` is called.

In my first impression, it is okay, but I'd like to hear opinions. @jeremyevans0 Do you have any opinion?

----------------------------------------
Bug #19026: Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.
https://bugs.ruby-lang.org/issues/19026#change-99377

* Author: ioquatix (Samuel Williams)
* Status: Open
* Priority: Normal
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN
----------------------------------------
Introduce the following interface:

```
Coverage.supported?(eval) -> true/false
```

We can also check `lines` `branches` and `methods`?



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

[ruby-core:110121] [Ruby master Bug#19026] Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.

[ioquatix (Samuel Williams)]

Issue #19026 has been updated by ioquatix (Samuel Williams).


Commit is currently part of https://github.com/ruby/ruby/pull/6462

----------------------------------------
Bug #19026: Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.
https://bugs.ruby-lang.org/issues/19026#change-99378

* Author: ioquatix (Samuel Williams)
* Status: Open
* Priority: Normal
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN
----------------------------------------
Introduce the following interface:

```
Coverage.supported?(eval) -> true/false
```

We can also check `lines` `branches` and `methods`?



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

[ruby-core:110124] [Ruby master Bug#19026] Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.

[mame (Yusuke Endoh)]

Issue #19026 has been updated by mame (Yusuke Endoh).


I think it is reasonable to have this feature to determine if `Coverage.start(eval: true)` is available. (Note that `Coverage.start(eval: true)` just ignores the keyword in Ruby 3.1 or before.)

@ioquatix I would like you to merge the PR to restore the continuous coverage measurement.

If there is anyone who has an opinion against this feature, feel free to add a comment.

----------------------------------------
Bug #19026: Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.
https://bugs.ruby-lang.org/issues/19026#change-99380

* Author: ioquatix (Samuel Williams)
* Status: Open
* Priority: Normal
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN
----------------------------------------
Introduce the following interface:

```
Coverage.supported?(eval) -> true/false
```

We can also check `lines` `branches` and `methods`?



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

[ruby-core:110128] [Ruby master Bug#19026] Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.

[Dan0042 (Daniel DeLorme)]

Issue #19026 has been updated by Dan0042 (Daniel DeLorme).


Isn't there a general mechanism for feature support? Like `RbConfig.support?(:eval_coverage)` or something?

----------------------------------------
Bug #19026: Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.
https://bugs.ruby-lang.org/issues/19026#change-99386

* Author: ioquatix (Samuel Williams)
* Status: Open
* Priority: Normal
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN
----------------------------------------
Introduce the following interface:

```
Coverage.supported?(eval) -> true/false
```

We can also check `lines` `branches` and `methods`?



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

[ruby-core:110129] [Ruby master Bug#19026] Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.

[jeremyevans0 (Jeremy Evans)]

Issue #19026 has been updated by jeremyevans0 (Jeremy Evans).


mame (Yusuke Endoh) wrote in #note-1:
> Note: This API does determine if the mode is *available*, not *enabled*. So `Coverage.supported?(:eval)` will always returns `true` in Ruby 3.2 regardless of whether `Coverage.start(eval: true)` is called.
> 
> In my first impression, it is okay, but I'd like to hear opinions. @jeremyevans0 Do you have any opinion?

I think having `Coverage.supported?` return true when it is supported is fine.  However, it would be useful to have an API such as `Coverage.activated?` that only returns true when the specific coverage feature is currently enabled.

----------------------------------------
Bug #19026: Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.
https://bugs.ruby-lang.org/issues/19026#change-99387

* Author: ioquatix (Samuel Williams)
* Status: Open
* Priority: Normal
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN
----------------------------------------
Introduce the following interface:

```
Coverage.supported?(eval) -> true/false
```

We can also check `lines` `branches` and `methods`?



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

[ruby-core:110135] [Ruby master Bug#19026] Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.

[mame (Yusuke Endoh)]

Issue #19026 has been updated by mame (Yusuke Endoh).


Dan0042 (Daniel DeLorme) wrote in #note-4:
> Isn't there a general mechanism for feature support? Like `RbConfig.support?(:eval_coverage)` or something?

I don't think it makes sense because this doesn't change depending on the ruby config.


jeremyevans0 (Jeremy Evans) wrote in #note-5:
> I think having `Coverage.supported?` return true when it is supported is fine.  However, it would be useful to have an API such as `Coverage.activated?` that only returns true when the specific coverage feature is currently enabled.

Thank you for your comment.

@ioquatix didn't write the use case. He wants to use his own coverage measurement based on TracePoint if "coverage for eval" feature is not supported (i.e., in Ruby 3.1 or before). TBH I am not sure if this is a common use case. @ioquatix isn't `RUBY_VERSION > "3.1"` enough for your case?

I am not so positive to have `Coverage.activated?(:eval or something)` because I don't allow users to write code that changes behavior depending on whether/which coverage is enabled or not. But we already have `Coverage.running?`, so I am okay if there is a common use case for `Coverage.activated?`.

----------------------------------------
Bug #19026: Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.
https://bugs.ruby-lang.org/issues/19026#change-99394

* Author: ioquatix (Samuel Williams)
* Status: Open
* Priority: Normal
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN
----------------------------------------
Introduce the following interface:

```
Coverage.supported?(eval) -> true/false
```

We can also check `lines` `branches` and `methods`?



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

[ruby-core:110139] [Ruby master Bug#19026] Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.

[Eregon (Benoit Daloze)]

Issue #19026 has been updated by Eregon (Benoit Daloze).


mame (Yusuke Endoh) wrote in #note-6:
> @ioquatix isn't `RUBY_VERSION > "3.1"` enough for your case?

Please no. For instance other Ruby implementations might already support eval Coverage trivially or can't support it easily, it should be a feature detection, not a hardcoded version check.
+1 for `Coverage.supported?(:eval)`.

----------------------------------------
Bug #19026: Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.
https://bugs.ruby-lang.org/issues/19026#change-99397

* Author: ioquatix (Samuel Williams)
* Status: Open
* Priority: Normal
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN
----------------------------------------
Introduce the following interface:

```
Coverage.supported?(eval) -> true/false
```

We can also check `lines` `branches` and `methods`?



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

[ruby-core:110140] [Ruby master Bug#19026] Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.

[Dan0042 (Daniel DeLorme)]

Issue #19026 has been updated by Dan0042 (Daniel DeLorme).


> > Isn't there a general mechanism for feature support? Like `RbConfig.support?(:eval_coverage)` or something?
>
> I don't think it makes sense because this doesn't change depending on the ruby config.

I didn't mean RbConfig per se, just any kind of general mechanism. It seems there isn't.
 

Eregon (Benoit Daloze) wrote in #note-7:
> +1 for `Coverage.supported?(:eval)`.

But then to use this API you need to do
`Coverage.respond_to?(:supported?) && Coverage.supported?(:eval)`
or shorten it to just
`Coverage.respond_to?(:supported?)`

----------------------------------------
Bug #19026: Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.
https://bugs.ruby-lang.org/issues/19026#change-99398

* Author: ioquatix (Samuel Williams)
* Status: Open
* Priority: Normal
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN
----------------------------------------
Introduce the following interface:

```
Coverage.supported?(eval) -> true/false
```

We can also check `lines` `branches` and `methods`?



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

[ruby-core:110141] [Ruby master Bug#19026] Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.

[ioquatix (Samuel Williams)]

Issue #19026 has been updated by ioquatix (Samuel Williams).

Status changed from Open to Closed

I agree, for the existing Ruby implementations, it's a little clumsy but easily worked around using `respond_to?`. Going forward, this is a simple and good interface.

Merged PR.

----------------------------------------
Bug #19026: Add `Coverage.supported?(x)` to detect support for `eval` coverage flag.
https://bugs.ruby-lang.org/issues/19026#change-99399

* Author: ioquatix (Samuel Williams)
* Status: Closed
* Priority: Normal
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN
----------------------------------------
Introduce the following interface:

```
Coverage.supported?(eval) -> true/false
```

We can also check `lines` `branches` and `methods`?



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