[REVERTED] Use file-scoped namesapces in RabbitMQ.Client project

[ArminShoeibi]

Proposed Changes

Hi there folks.
this merge request changes old namespaces to file-scoped namespaces in RabbitMQ.Client project.
if we want to change other projects such as tests and samples we need to drop net4.7.2 support.

Types of Changes

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• Bug fix (non-breaking change which fixes issue #NNNN)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause an observable behavior change in existing systems)
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• Cosmetic change (whitespace, formatting, etc)

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• I have read the CONTRIBUTING.md document
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• All tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
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• Any dependent changes have been merged and published in related repositories

Further Comments

Tests of net472
Before:

After:

Tests of net6.0
Before:

After:

[michaelklishin]

@ArminShoeibi thank you for taking the time. What's the minimum .NET requirement with this change? I see it requires C# 10 but we express requirements in terms of .NET release series. I am not sure we can drop 4.7 at this point, although there were recent discussions about going to 4.8 or 5.0.

Using old style namespaces in tests and examples is OK. We need to understand what this PR means for version requirements before merging.

[michaelklishin]

I see our tests already target .NET 6.0. Nice. RUNNING_TESTS.md is now up-to-date for May 2022, with the potential exception of running individual tests.

@ArminShoeibi I'm quite sure the failing tests you see require a locally running RabbitMQ
node as I don't get any in main:

Test Run Successful.
Total tests: 252
     Passed: 246
    Skipped: 6
 Total time: 10.1903 Minutes

[michaelklishin]

All tests pass on this branch as well:

Test Run Successful.
Total tests: 252
     Passed: 246
    Skipped: 6
 Total time: 10.3054 Minutes

[michaelklishin]

Found the supported minimum version discussion: #1189.

[ArminShoeibi]

I see our tests already target .NET 6.0. Nice. RUNNING_TESTS.md is now up-to-date for May 2022, with the potential exception of running individual tests.

@ArminShoeibi I'm quite sure the test failures you see require a locally running RabbitMQ node as I don't get any in main:

Test Run Successful.
Total tests: 252
     Passed: 246
    Skipped: 6
 Total time: 10.1903 Minutes

Oh I got it, So I needed a RabbitMQ node on my localhost
Thank you dear Michael @michaelklishin

[michaelklishin]

@ArminShoeibi @lukebakken should we backport this to 7.x? The milestone says so, and it would be much easier to backport all future changes from main to 7.x if we do.

I can spend some time on doing that if you agree (and no one else volunteers!)

[ArminShoeibi]

@ArminShoeibi @lukebakken should we backport this to 7.x? The milestone says so, and it would be much easier to backport all future changes from main to 7.x if we do.

I can spend some time on doing that if you agree (and no one else volunteers!)

I'm okay with it.

[michaelklishin]

I run into

projects/RabbitMQ.Client/client/api/IBasicConsumer.cs(98,13): error CS0246: The type or namespace name 'ReadOnlyMemory<>' could not be found

as soon as I change any or all .csproj files to use

<TargetFrameworks>net6.0;netstandard2.0</TargetFrameworks>
<LangVersion>latest</LangVersion>

on the 7.x branch. Since ReadOnlyMemory<> comes from the System.Runtime assembly,
I am not sure what reference or import may be missing.

[michaelklishin]

I concluded that we should revert this. It's a nice feature but it makes backports of PRs between branches impossible unless they all use it, and it requires C# 10, which means all branches we support in any capacity won't be able to adopt it for a good year if not two.