[gmpassos]

Summary

This makes ClassReflection.createInstanceFromMap faster. bones_api calls it for every DB row, and its profile puts it at ~23% of SQLite user/list CPU.

• Generator: a direct invoker per constructor. It calls the constructor without Function.apply:

  invoker: (a) => Foo.named(
    a[0] as String,
    x: identical(a[1], ConstructorReflection.absentArgument) ? 0 : a[1] as double,
  ),

  • Each argument is cast to its parameter type, so the generated code is clean under strict-casts.
  • An omitted optional or named parameter arrives as ConstructorReflection.absentArgument. The invoker then passes the default written in its own code, in the parameter's type context, so double x = 0 gets 0.0 and const [] becomes a List<String>.
  • A constructor whose parameter type uses a type parameter (T, List<T>) gets no invoker and keeps using Function.apply.
  • Code generated by earlier versions has no invoker and keeps using Function.apply.
• createInstanceWithConstructor calls constructors through invokeWith(MethodInvocation). When there is no fieldValueResolver, it builds the invoker arguments straight from the map. That covers constructors without optional positional parameters, in classes without JSON name aliases.
  • The values passed are the same as before. A single "omittable parameter" rule is shared with methodInvocation.
  • Errors are reported as before, through the same retry/report logic, and the constructor isn't called again with the same arguments.
• createInstanceFromMap(valuesResolved:, exactKeys:): options for maps whose values are already resolved (fieldValueResolver is ignored) and whose keys are the exact names (no matching on _ prefix or case).
• Field-setting fallback (create() + setters): it no longer allocates a FieldReflection per field and row.
• Constructor choice: 2.11.0 already caches it per map shape; unchanged here.
• Version: bumped to 2.12.0 (v2.11.0 is tagged), and the checked-in .g.dart files are regenerated.

Review fixes (ef2fef1)

• The first version passed the reflected ParameterReflection.defaultValue for omitted parameters. That value has the wrong type for double x = 0 (an int) and for untyped const [], so calls threw a TypeError. Defaults are now written into the generated code.
• Invoker arguments are now cast (strict-casts).
• A direct call that throws is no longer followed by a second call of the constructor.
• valuesResolved is no longer passed through 4 more public signatures.

Benchmarks

benchmark/create_instance_from_map.dart (--markdown entries in benchmark/HISTORY.md). Apple M5, JIT, alternated with 2.11.0:

Case	2.11.0	2.12.0
account: constructor	3110 ns	450 ns (−85.5%)
account: constructor (valuesResolved, exactKeys)	—	385 ns
account: fromJson	4454 ns	3035 ns (−31.9%)
member: create + setters	1020 ns	750 ns (−26.5%)

bones_api db_users on SQLite, ops/sec, alternated, with the reflection regenerated:

Operation	bones_api unchanged	with the options in instantiateFromMapImpl
user/list	+8–11%	+24–33%
user/byState	+10.5%	+22–30%
user/byId	+7.7%	+18–20%

Note for bones_api: instantiateFromMapImpl is also reached from JSON (e.g. storeAllFromJson), where values are not resolved (enum names, DateTime strings, lists of maps). Passing valuesResolved: true on that path breaks entities with such fields. Pass the options only where values are already resolved (DB rows).

Test plan

• test/reflection_factory_instantiate_test.dart checks that Function.apply, the invoker via MethodInvocation, and the direct call give the same results or errors for:
  • absent and null named parameters, with and without defaults;
  • int-literal defaults of double parameters and typed const []/const {} defaults;
  • function-typed parameters;
  • required named parameters;
  • wrong types and extra keys;
  • optional positional parameters;
  • super parameters with inherited defaults;
  • JSON alias classes;
  • the create + setters fallback;
  • a reflection bound to an object;
  • exactKeys.
    It also checks that no invoker is generated for type-parameter types and that a constructor which throws is called once per attempt.
• The build test asserts the emitted typed invoker: code.
• dart analyze and dart format are clean, and dart test passes all 538 tests. The generated code also analyzes clean under strict-casts.
• bones_api db_users API tests pass on 2.12.0, both unchanged and with the options.
• A larger downstream codebase regenerated with 2.12.0 analyzes clean, and its full test suite passes with bones_api unchanged. The only failure is its ensure_build, which is expected because the reflection was regenerated.

🤖 Generated with Claude Code

[codecov]

Codecov Report

❌ Patch coverage is 81.31313% with 37 lines in your changes missing coverage. Please review.
✅ Project coverage is 93.53%. Comparing base (77164c6) to head (5411694).

Files with missing lines	Patch %	Lines
lib/src/reflection_factory_builder.dart	69.67%	37 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #57      +/-   ##
==========================================
+ Coverage   92.56%   93.53%   +0.97%     
==========================================
  Files          14       14              
  Lines        6428     6532     +104     
==========================================
+ Hits         5950     6110     +160     
+ Misses        478      422      -56     

Flag	Coverage Δ
unittests	93.53% <81.31%> (+0.97%)	⬆️

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