fix(metrics): explicit type to single_metric ctx manager

[whardier]

Issue #, if available:

• Maintenance: address top papercuts #857

Description of changes:

Simply update type return for metrics.metric.single_metric.

Checklist

• Meet tenets criteria
• Update tests
• Update docs
• PR title follows conventional commit semantics

Breaking change checklist

RFC issue #:

• Migration process documented
• Implement warnings (if it can live side by side)

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[codecov-commenter]

Codecov Report

Merging #865 (de51add) into develop (8cfa773) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##           develop     #865    +/-   ##
=========================================
  Coverage    99.90%   99.90%            
=========================================
  Files          118      118            
  Lines         5125     5126     +1     
  Branches       283      571   +288     
=========================================
+ Hits          5120     5121     +1     
  Misses           2        2            
  Partials         3        3            

Impacted Files	Coverage Δ
aws_lambda_powertools/metrics/metric.py	100.00% <100.00%> (ø)
...wertools/utilities/idempotency/persistence/base.py	99.37% <0.00%> (+<0.01%)	⬆️

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[heitorlessa]

One minor change to use Generator[SingleMetric, None, None] due to a new issue discovered in Python typeshed when using Iterator[] in this context.

[heitorlessa]

I created a new project using VSCode and PyLance and I couldn't reproduce this issue, same with PyCharm so perhaps their InteliSense is smart by inspecting the yield type SingleMetric.

Nevertheless, TIL why we can't use Iterator[SingleMetric] and instead should use Generator[SingleMetric, None, None.

For the sake of correctness regardless of what IDE one might use, I'm gonna commit the Generator suggestion to avoid issues and merge it.

[whardier]

Interesting. I poured over a ton of python code and standard libs and Iterator seemed like the best fit. I will read up on this.

[heitorlessa]

Yep same. It seems to be a “new” thing

…

On Wed, 8 Dec 2021 at 16:15, Shane R. Spencer ***@***.***> wrote: Interesting. I poured over a ton of python code and standard libs and Iterator seemed like the best fit. I will read up on this. — You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub <#865 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAZPQBAG6AJVV5US52MDV5LUP5ZA3ANCNFSM5JH6AMOA> .