fix(concerto-core): serialize maps with cross-namespace concept values

[mttrbrts]

Problem

When a Concerto map has a concept value type that is imported from another namespace, (de)serialization breaks. Both the serializer and the populator resolved the value concept's declaration by searching only the map's own model file:

mapDeclaration.getModelFile().getAllDeclarations().find(decl => decl.name === value.getType())

An imported value concept isn't in that model file, so the lookup returns undefined, and:

• Serializer.toJSON throws TypeError: Cannot read properties of undefined (reading 'accept').
• Serializer.fromJSON silently returns the raw JSON object instead of a populated Concept, which breaks round-tripping (toJSON(fromJSON(x))).

Reproduction

namespace org.acme.unit@1.0.0
concept MonetaryUnit { o String code  o Integer scale }

namespace org.acme.registry@1.0.0
import org.acme.unit@1.0.0.{MonetaryUnit}
map UnitMap { o String  o MonetaryUnit }
concept Registry { o UnitMap units optional }

Building a Registry with a populated units map and calling serializer.toJSON(...) throws. Same-namespace maps (e.g. the existing Rolodex/Directory tests) are unaffected.

Fix

Resolve the value declaration across all loaded models rather than just the map's own model file:

• jsongenerator.ts (visitMapDeclaration): resolve the map's declared value type honouring imports, via ModelFile.getFullyQualifiedTypeName(...) + ModelManager.getType(...). This works for both factory-created and populator-created value instances (some of which don't expose getFullyQualifiedType()).
• jsonpopulator.ts (processMapType): search declarations across every model file, preserving the existing .find(...)/fallthrough semantics so same-namespace behaviour is unchanged.

Tests

Added to test/serializer/maptype/serializer.js:

• serialize → deserialize → re-serialize (round-trip) of a map whose value concept is imported from another namespace (the previously-crashing case).

Full test/serializer/** suite passes (235 tests); eslint . is clean on the changed files.

Known related follow-up (not addressed here)

Serializer.fromJSON does not appear to run field-level validation on concept values inside a map — a map entry missing a required field is populated without error. That is a separate validator-depth issue (not caused by the declaration-lookup bug fixed here) and is left for a follow-up to keep this change focused.

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Fixes Concerto map (de)serialization when the map’s value concept type is imported from another namespace, by resolving the value declaration across loaded models instead of only within the map’s defining model file—restoring correct round-tripping behavior in concerto-core’s serializer.

Changes:

• Update JSON generation for map entries to resolve the map value type using import-aware, model-manager-based lookup.
• Update JSON population for map entries to find the correct declaration even when the value concept is imported from a different namespace.
• Add a regression test covering serialize → deserialize → re-serialize for a cross-namespace map value concept.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
packages/concerto-core/src/serializer/jsongenerator.ts	Adjusts map value declaration resolution during serialization to support imported value concepts.
packages/concerto-core/src/serializer/jsonpopulator.ts	Adjusts map value declaration lookup during deserialization to support imported value concepts.
packages/concerto-core/test/serializer/maptype/serializer.js	Adds regression test for cross-namespace concept values in maps and round-trip behavior.

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