Add missing open declaration as possible issue when warning about uppercase pattern names

[jbeeko]

The following code:

module A =
    type A = Foo | Bar
module B =
    open A
    let a = Foo
module C =
    open B
    match a with
    | Bar -> Bar.ToString()

Will result in the following compiler warning:

      | Bar -> Bar.ToString()
  ------^^^

stdin(9,7): warning FS0049: Uppercase variable identifiers should not generally be used in patterns, and may indicate a misspelt pattern name.

While a misspelling may be the culprit in the experience of our team it is also common for this to be due to a missing open declaration as in the example above. In the case where this is due to a missing open declaration the warning message does not help at all and has left team members quite confused.

This PR changes the warning resource string so that the the following warning is presented:

      | Bar -> "bar";;
  ------^^^

stdin(18,7): warning FS0049: Uppercase variable identifiers should not generally be used in patterns, and may indicate a missing open declaration or a misspelt pattern name.

Unfortunately I have no ability to contribute messages in the other languages supported.

See #6712

[dnfclas]

All CLA requirements met.

[cartermp]

@jbeeko Some failing tests:

Conformance\Expressions\DataExpressions\QueryExpressions (W_UppercaseIdentifier01.fs) -- failed
Conformance\Expressions\DataExpressions\QueryExpressions (W_UppercaseIdentifier02.fs) -- failed
Conformance\Expressions\DataExpressions\QueryExpressions (W_UppercaseIdentifier03.fs) -- failed

https://dev.azure.com/dnceng/public/_build/results?buildId=597987&view=ms.vss-test-web.build-test-results-tab&runId=18834804&resultId=100292&paneView=debug

[abelbraaksma]

Unfortunately I have no ability to contribute messages in the other languages supported.

@jbeeko If I'm not mistaken, that's automatically done by the translation team if Microsoft, which is triggered upon changes in the resource files. I forgot the exact procedure, but I'm sure @cartermp can point you in the right direction.

Edit: sorry, @cartermp didn't see you were already in this thread.

[jbeeko]

@cartermp thanks, I'll see how I can replicate those failures locally.

[jbeeko]

I changed the warning to :

Uppercase variable identifiers should not generally be used in patterns, and may indicate a missing open declaration or a misspelt pattern name.

But it occurs to me it this is a bit prescriptive, it could also be:

Uppercase variable identifiers should not generally be used in patterns, and may indicate a a misspelt or out of scope pattern name.

On balance I prefer the advise to add an open statement because it provides concrete advice.

[cartermp]

@jbeeko I think the first warning is pretty good.

[abelbraaksma]

Uppercase variable identifiers should not generally be used in patterns, and may indicate a missing open declaration or a misspelt pattern name.

Fwiw, I prefer the first one too (btw, the 2nd one has a double 'a a').

[KevinRansom]

@jbeeko , thank you for taking care of this.