chore: ease maintenance of upcoming parser #118

[heitorlessa]

Issue #, if available: #118

Description of changes:

Minor internal changes to ensure consistency across utilities, and ease maintenance before we write docs.

Checklist

• Update docs
• Update tests
• Meet tenets criteria
• PR title follows conventional commit semantics
• Remove validators. We need an universal schema owned by Lambda for each event source, or else we'll likely break some customers if a few services change, as we won't be notified.
• Snake_case. IIRC, EventBridge detailtype was the only odd one out but I'll double check if there are others
• Kwargs over args. Some internal code is using args over kwargs - Moving to kwargs make it easier to refactor, and order of args wouldn't be impacted.
• Docstrings. Enhance Example section in docstrings, and areas where we need more clarity for future maintenance
• Raise own Validation Exception. For customers wanting to catch that exception (e.g. custom middlewares) they'll have to find Pydantic exception to catch it properly
• Enhance imports. Envelopes and a few others can be turned into high level imports to clean up customers' code, plus DX.
• Simplify internals of envelope: Parsing dict event, obj event, and string event share similar logic; wrap them under a single _parse
• Fix PyCharm inspect issues
• Test coverage. Validation errors aren't being tested as of now.
• Refactor seemingly duplicates to ease maintenance
• Chain exceptions with own exception to ease debugging
• [Optional] Enhancing envelope selection. Time allowing, I'll experiment with providing a similar experience we have in the validator envelope utility envelope.<event_source>.
• Revisit chain of try/catch: Allow exceptions to propagate, and use exception chaining to provide more details instead.
• Expose Pydantic import system: Common imports from Pydantic such as validator, root_validator, and BaseModel should be part of the high level import system. Uncommon imports such as json, dataclasses, should be available nevertheless but ring fenced.
• [Optional] Create a standalone parser. Time allowing, I'll experiment creating a standalone parser function with the same functionality the decorator
• Remove flake8 polyfill. Double check whether a fresh Python env hits the issue you hit with that, since we don't use it
• [Optional] Support for API Gateway, Kinesis, S3, and SNS. Likely to be after 1.7.0, but time allowing we can do that sooner.
• Revisit Schemas naming. DynamoDBScheme vs DynamoDBSchema - might be best looked at when writing docs

Note: Decided to refactor test event data as a separate PR to prevent cluttering non-parser changes here. Data_classes and validator utility are partially using the same events, so we'll refactor tests to provide events to all tests as fixtures.

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 #189 into develop will increase coverage by 0.39%.
The diff coverage is 95.06%.

@@             Coverage Diff             @@
##           develop     #189      +/-   ##
===========================================
+ Coverage    99.20%   99.59%   +0.39%     
===========================================
  Files           64       64              
  Lines         2505     2468      -37     
  Branches       113      108       -5     
===========================================
- Hits          2485     2458      -27     
+ Misses          14        8       -6     
+ Partials         6        2       -4     

Impacted Files	Coverage Δ
...da_powertools/utilities/parser/schemas/__init__.py	100.00% <ø> (ø)
...mbda_powertools/utilities/parser/envelopes/base.py	86.48% <84.61%> (ø)
...ertools/utilities/parser/envelopes/event_bridge.py	85.71% <85.71%> (ø)
aws_lambda_powertools/utilities/parser/__init__.py	100.00% <100.00%> (ø)
..._powertools/utilities/parser/envelopes/__init__.py	100.00% <100.00%> (ø)
..._powertools/utilities/parser/envelopes/dynamodb.py	100.00% <100.00%> (ø)
...ambda_powertools/utilities/parser/envelopes/sqs.py	100.00% <100.00%> (ø)
...s_lambda_powertools/utilities/parser/exceptions.py	100.00% <100.00%> (ø)
aws_lambda_powertools/utilities/parser/parser.py	100.00% <100.00%> (ø)
...da_powertools/utilities/parser/schemas/dynamodb.py	100.00% <100.00%> (ø)
... and 8 more

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Δ = absolute <relative> (impact), ø = not affected, ? = missing data
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[codecov-io]

Codecov Report

Merging #189 into develop will increase coverage by 0.67%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop     #189      +/-   ##
===========================================
+ Coverage    99.20%   99.87%   +0.67%     
===========================================
  Files           64       65       +1     
  Lines         2505     2451      -54     
  Branches       113      108       -5     
===========================================
- Hits          2485     2448      -37     
+ Misses          14        3      -11     
+ Partials         6        0       -6     

Impacted Files	Coverage Δ
aws_lambda_powertools/utilities/parser/__init__.py	100.00% <100.00%> (ø)
..._powertools/utilities/parser/envelopes/__init__.py	100.00% <100.00%> (ø)
...mbda_powertools/utilities/parser/envelopes/base.py	100.00% <100.00%> (ø)
..._powertools/utilities/parser/envelopes/dynamodb.py	100.00% <100.00%> (ø)
...ertools/utilities/parser/envelopes/event_bridge.py	100.00% <100.00%> (ø)
...ambda_powertools/utilities/parser/envelopes/sqs.py	100.00% <100.00%> (ø)
...s_lambda_powertools/utilities/parser/exceptions.py	100.00% <100.00%> (ø)
...bda_powertools/utilities/parser/models/__init__.py	100.00% <100.00%> (ø)
...bda_powertools/utilities/parser/models/dynamodb.py	100.00% <100.00%> (ø)
...powertools/utilities/parser/models/event_bridge.py	100.00% <100.00%> (ø)
... and 15 more

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[heitorlessa]

@cakepietoast ready when you are -- this is mostly semantics to ease maintenance after publishing the parser utility -- Could you take a look and see if the docstrings, import system, etc. are to what you'd expect too?

The additional conftest for parser, test data from data_classes, etc. will be dealt with in a separate PR - We need to consolidate all those JSON into fixtures available to all functional tests to prevent unnecessary I/O + easier to use.

[heitorlessa]

Next steps before 1.7.0:

• Review by @cakepietoast
• Parser docs

[to-mc]

LGTM - with the sole suggestion of renaming the parser function!