Fix exported GDScript struct array editing in the Inspector

[Arctis-Fireblight]

Fixes 1442

Array[Struct] elements created by resizing in the inspector had no struct schema, so the Inspector could not expose their fields.

• Implement caching for array struct element defaults in GDScript.
• Extend GDScript API to retrieve schema-backed defaults for array elements.
• Update editor to initialize new array elements with struct defaults where applicable.
• Add tests to validate default value behavior for exported array elements.

Summary by CodeRabbit

• New Features
  • When you add elements to an exported array of experimental structs in the Inspector, each new element now starts with the struct’s schema-defined default values. This preserves configured values, such as boolean and numeric defaults, in newly added entries. Defaults are also available for applicable exported array properties inherited from a base script. Existing elements and arrays without applicable struct defaults continue to behave as before.

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ℹ️ Recent review info

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Review profile: CHILL

Plan: Advanced

Run ID: c59b10af-1b74-45a7-a154-9ae7f6115cf9

📥 Commits

Reviewing files that changed from the base of the PR and between bc35638 and 2dd281a.

📒 Files selected for processing (1)

• editor/inspector/editor_properties_array_dict.cpp

🚧 Files skipped from review as they are similar to previous changes (1)

• editor/inspector/editor_properties_array_dict.cpp

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Walkthrough

GDScript caches schema-backed defaults for eligible exported struct arrays. When the inspector grows an array and a non-null struct default is available, it assigns that default to each new element.

Changes

Struct array defaults

Layer / File(s)	Summary
Build and expose element defaults core/object/script_language.h, modules/gdscript/gdscript.h, modules/gdscript/gdscript.cpp, modules/gdscript/tests/gdscript_test_runner_suite.h	Script adds an array-element default query. GDScript caches schema defaults for exported arrays with typed, non-nullable struct elements and can retrieve them through the query, including through the base-script cache. A test checks that the returned struct preserves its declared field defaults.
Apply defaults when resizing arrays editor/inspector/editor_properties_array_dict.h, editor/inspector/editor_properties_array_dict.cpp	The inspector checks whether the edited object's script provides a non-null struct default. When it does, array resizing assigns the default to each newly added index. Otherwise, resizing leaves new elements as initialized by resize.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

Sequence Diagram(s)

sequenceDiagram
  actor Editor
  participant EditorPropertyArray
  participant GDScript
  Editor->>EditorPropertyArray: Increase array length
  EditorPropertyArray->>GDScript: Query element default
  GDScript-->>EditorPropertyArray: Return cached struct default
  EditorPropertyArray->>EditorPropertyArray: Duplicate default into new indices

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Suggested reviewers: mcdubhghlas, generalprotectionfault

Merge Risk: ⚪ Minimal · up to 2dd28

The change caches default values for struct array elements and applies them when the Inspector resizes an array. No actionable merge-blocking risk was identified from the supplied context.

Security Architecture Review

Security architecture risk: 🟡 Moderate · up to bc356

New array elements can share mutable data inside their struct defaults, so changing one element may unexpectedly affect other elements or defaults used later. The behavior is limited to editor initialization; no new privileged access path was identified.

Retained concerns

• Medium · reliability · inferred: New struct elements have independent top-level storage but can share mutable Array or Dictionary fields with each other and the cached schema default. Mutation through a retained nested field can therefore change sibling values or defaults returned for later elements.

Security review details

Security Blast Radius

• inferred — The identified mutable-state effect is bounded by uses of a script property's cached default and elements initialized from it in the editor. The reviewed path does not establish a service, tenant, credential, or network authority transition.

Trust Boundaries and Controls

• observed — User-authored script schema data reaches the inspector through export analysis and the Script query. Eligibility checks constrain cache population, and the inspector rejects unavailable, wrong-type, or null struct defaults; these controls do not deep-clone nested fields on copy-out.

Resilience and Maintainability Implications

• inferred — Ordinary Struct copying protects top-level field storage but leaves reference-backed nested fields shared. Property-value undo or replacement alone need not restore a cached default if that nested storage has been mutated through another copy.

Hardening Proposals

• proposed — Give each returned or inserted schema default independent nested mutable containers, and verify sibling isolation, later queries, undo, and failed-refresh behavior with lifecycle tests.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 14 functions across 6 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: fixing the editing of exported GDScript struct arrays in the Inspector.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create a new PR

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Actionable comments posted: 1

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Inline comments:
Review comments at @editor/inspector/editor_properties_array_dict.cpp:
- Line 880: Update the array population code around `array.set` to
deep-duplicate `element_default` for each new element, so nested Array and
Dictionary fields are not shared with other elements or the cached default.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository: Redot-Engine/redot-engine/.coderabbit.yaml

Review profile: CHILL

Plan: Advanced

Run ID: 0e9280dc-77a7-456e-9dbe-20213a35342f

📥 Commits

Reviewing files that changed from the base of the PR and between cfb04f1 and 7d52900.

📒 Files selected for processing (6)

• core/object/script_language.h
• editor/inspector/editor_properties_array_dict.cpp
• editor/inspector/editor_properties_array_dict.h
• modules/gdscript/gdscript.cpp
• modules/gdscript/gdscript.h
• modules/gdscript/tests/gdscript_test_runner_suite.h

Included review availability: This review used your included allowance. Your plan provides up to 8 included reviews per hour; 7 remain after this review.