🚀 Pull Request

📋 Summary

Fixes two bugs that prevented [DynamoField] dot-notation overrides from working when an intermediate path segment is a collection (List<T>, T[], Dictionary<string, T>, etc.).

Example that now works:

[DynamoMapper]
[DynamoField("Contacts.VerifiedAt", Format = "yyyy-MM-dd")]
[DynamoField("Contacts.Name", AttributeName = "contact_name")]
public static partial class CustomerMapper { ... }

Bug 1 — ValidatePath() in ModelClassInfo.cs traversed directly into List<CustomerContact> when resolving the Contacts segment, causing a false DM0008 diagnostic. Fix: after the existing nullable unwrap, now also calls CollectionTypeAnalyzer.Analyze() to unwrap to the element type before advancing.

Bug 2 — CreateCollectionStrategy() in TypeMappingStrategyResolver.cs created a fresh NestedAnalysisContext with an empty path, so GetFieldOptionsForProperty("VerifiedAt") looked up "VerifiedAt" instead of "Contacts.VerifiedAt". Additionally, CollectionTypeAnalyzer.ValidateElementType() called NestedObjectTypeAnalyzer.Analyze() with the dummy property name "element", which further corrupted the path. Fix: a new AnalyzeElementType() method bypasses the path-append that Analyze() performs, and callers supply the correct path prefix up-front.

The fix applies uniformly to List<T>, T[], Dictionary<string, T>, and collections nested within nested objects.

✅ Checklist

• My changes build cleanly
• I've added/updated relevant tests
• I've added/updated documentation or README
• I've followed the coding style for this project
• I've tested the changes locally (if applicable)

🧪 Related Issues or PRs

Closes #91

💬 Notes for Reviewers

Three source files changed:

• ModelClassInfo.cs — 4-line addition in ValidatePath(), no logic removed
• CollectionTypeAnalyzer.cs — swap Analyze(..., "element", ...) for new AnalyzeElementType(...)
• NestedObjectTypeAnalyzer.cs — new internal AnalyzeElementType() method + one-line change in AnalyzeForInline() to pass contextWithAncestor.WithPath(property.Name) for collection properties within nested objects

6 new snapshot tests in CollectionDotNotationVerifyTests.cs cover List<T>, T[], Dictionary<string, T>, multiple overrides on the same element type, and a DM0008 regression guard for invalid element property names.