Add IBM cost analysis

[glen-84]

Summary of the changes (Less than 80 chars)

• Adds IBM cost analysis.

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❓ Questions

• What am I doing wrong with the error handling in CostAnalysisMiddleware? It doesn't end the request. It's probably something silly. [@michaelstaib]

• Is it important that a fragment definition is visited after it is spread? If you spread it twice, it is only visited once.

  • It seems logical that it would be visited from the root, not after it is first spread. This makes the path generation awkward, since you end up with paths like: query.examples.example1Field2[0].~fragment1~~fragment1.@example by default instead of just ~~fragment1.@example (the fragment definition starts at the root). Would changing this break things?

• For unnamed operations, I've used o.Operation.ToString().ToLowerInvariant() for the path element – is that okay? ✅

  • f.e. query for an unnamed query, etc.

• For fragment spreads with no TypeCondition, I've used context.OutputFields.Peek().Type.TypeName() – is that okay?

  • i.e. The name of the type of the field on which the spread is defined.

• How do we avoid requiring the developer to add a @listSize directive to every single list in their project? Could we somehow attach this directive to connection types by default? [@michaelstaib]

  • RequireOneSlicingArgument would have to be set to false, otherwise the user would be forced to specify first or last.

• Should we support introspectionOnly? (https://ibm.github.io/graphql-specs/cost-spec.html#sec-introspectionOnly) [@michaelstaib]

• Should we support NoSchemaIntrospectionCustomRule? (https://ibm.github.io/graphql-specs/cost-spec.html#sec-NoSchemaIntrospectionCustomRule) - yes

• For the CostMetrics cache, how much memory can we use, what should the default cache size be, etc.? - we deal with that in a later pr

• I used the NonBacktracking option for the introspection regexes to reduce the chance of performance issues – should I keep this, or allow backtracking? - keep it!

• Is there a better way to handle optional value-typed attribute arguments in ListSizeAttribute (for AssumedSize)? Currently using a nullable backing field. - looks good

• Should we sort the fieldCostByLocation / typeCostByLocation by key (path)? - lets skip it and check if people have an issue with it

• I've not yet done anything with @skip/@include. I wonder if supporting static true/false is worth it? lets revisit this for the december release

✅ To-do:

• Directives on directive arguments (blocked by Add directives to directive arguments #7130)
• Schema validation (blocked by [internal])
• Support scalars (blocked by Adding directives to custom scalar types #1380)
• Fix paths for fragment definitions (see question above).
• ExecutionDiagnosticEventListener methods (blocked by [internal])

💡 Ideas

• Should we exit early as the costs exceed the maximums?
  • Under which conditions? (only in production, etc.)
• Should we log a warning when the default list size of 1 is used? (i.e. not configured with @listSize)

🛠️ FIXMEs: 6.

(search for FIXME in src/HotChocolate/CostAnalysis/)

[github-actions]

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[codecov]

Codecov Report

Attention: Patch coverage is 79.23920% with 322 lines in your changes missing coverage. Please review.

Project coverage is 71.03%. Comparing base (ce8b5f7) to head (ab67695).

Files	Patch %	Lines
...nalysis/src/CostAnalysis/Utilities/ResultHelper.cs	31.40%	83 Missing ⚠️
...lysis/Properties/CostAnalysisResources.Designer.cs	0.00%	24 Missing ⚠️
...late/CostAnalysis/src/CostAnalysis/CostAnalyzer.cs	91.11%	20 Missing ⚠️
...olate/CostAnalysis/src/CostAnalysis/ErrorHelper.cs	20.00%	20 Missing ⚠️
...rc/CostAnalysis/Utilities/CostAnalyzerUtilities.cs	80.95%	20 Missing ⚠️
...nalysis/src/CostAnalysis/CostAnalyzerMiddleware.cs	82.52%	18 Missing ⚠️
...Extensions/CostAnalyzerRequestContextExtensions.cs	35.71%	18 Missing ⚠️
.../Core/src/Abstractions/Execution/ResponseStream.cs	61.53%	15 Missing ⚠️
...src/AspNetCore/Extensions/HttpContextExtensions.cs	29.41%	12 Missing ⚠️
...is/src/CostAnalysis/Types/ListSizeDirectiveType.cs	91.86%	10 Missing ⚠️
... and 22 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7146      +/-   ##
==========================================
- Coverage   78.72%   71.03%   -7.69%     
==========================================
  Files        2371     2688     +317     
  Lines      117420   134282   +16862     
==========================================
+ Hits        92443    95393    +2950     
- Misses      24977    38889   +13912     

Flag	Coverage Δ
unittests	71.03% <79.23%> (-7.69%)	⬇️

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