feat(helpers): resolve functions from prototypes in fake

[hugosmoreira]

Summary

• resolve properties on primitive values returned by fakeEval
• bind generated object and primitive methods to their source value
• document member chaining for fakeEval and helpers.fake
• add regression coverage for implicit and explicit calls, properties, prototype methods, and constructor-chain safety

Root cause

The expression resolver only followed properties on objects. When a Faker method returned a primitive, the chain stopped; when it returned an object method such as Date.prototype.toISOString, the method was later invoked without its receiver.

The resolver now boxes supported primitives for property lookup and binds callable properties to the generated value. Functions returned by functions still use the existing recursive resolution path, preserving the constructor-chain protection added for GHSA-qxc2-j82w-r537.

Validation

• pnpm run preflight
  • 55 test files passed
  • 52,740 tests passed
  • TypeScript checks passed
• targeted helpers suites: 862 tests passed

Closes #3465

This contribution was developed and validated with OpenAI Codex assistance.

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[codecov]

Codecov Report

❌ Patch coverage is 83.33333% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 98.88%. Comparing base (717fa14) to head (831c6ce).

Files with missing lines	Patch %	Lines
src/modules/helpers/eval.ts	83.33%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             next    #3970      +/-   ##
==========================================
- Coverage   98.91%   98.88%   -0.03%     
==========================================
  Files         924      924              
  Lines        3224     3229       +5     
  Branches      585      569      -16     
==========================================
+ Hits         3189     3193       +4     
- Misses         31       32       +1     
  Partials        4        4              

Files with missing lines	Coverage Δ
src/modules/helpers/module.ts	94.84% <ø> (ø)
src/modules/helpers/eval.ts	97.29% <83.33%> (-1.26%)	⬇️

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[Copilot]

Pull request overview

This PR improves helpers.fake / fakeEval expression resolution so member access continues after generated primitive values and callable members are invoked with the correct receiver (this), fixing failures when chaining prototype methods (e.g., toISOString, trim, toPrecision).

Changes:

• Extend property resolution to box primitive generated values so properties and prototype members can be accessed after faker method calls.
• Bind callable resolved members to their source value to preserve correct receiver semantics.
• Add documentation and regression tests covering property/method chaining and constructor-chain safety.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
src/modules/helpers/eval.ts	Updates the resolver to box primitives for property lookup and bind callable properties to the generated value.
src/modules/helpers/module.ts	Documents member/property chaining behavior for helpers.fake.
test/modules/helpers.spec.ts	Adds regression coverage for helpers.fake chaining on primitives and prototype methods.
test/modules/helpers-eval.spec.ts	Adds regression coverage for fakeEval chaining (implicit/explicit calls) and extends the GHSA constructor-chain safety suite.

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