Fix Core Data model duplication test flakiness - #25932
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The unit tests share one process, and Core Data registers every loaded model's entities in a process-global class-to-entity table. Loading a historical schema version alongside the current one leaves two entity descriptions claiming the same NSManagedObject subclass, so +[X entity] can no longer resolve uniquely and crashes unrelated Core Data tests depending on execution order. Reset a loaded historical model's entity classes to the generic NSManagedObject so it never claims the concrete subclasses. The migration tests only reach their data by entity name and key-value coding, so they keep working.
Move currentObjectModel to a public extension so callers (including tests) can reuse the single process-wide model instance instead of loading a second copy of the same schema, which would register duplicate entity-to-class mappings.
createContext defaulted to a freshly merged copy of the current model, adding a second registration of the current schema's NSManagedObject subclasses to Core Data's process-global class-to-entity table and making unrelated tests crash depending on execution order. Use the shared ContextManager.currentObjectModel instead, and neutralize the entity classes of the older model versions the tests load on purpose so they no longer register duplicate concrete subclasses either.
It only covered migrations between the legacy model versions 103 and 104.
crazytonyli
marked this pull request as ready for review
August 24, 2026 03:48
crazytonyli
enabled auto-merge
August 24, 2026 03:48
Contributor
|
| App Name | WordPress | |
| Configuration | Release-Alpha | |
| Build Number | 33901 | |
| Version | PR #25932 | |
| Bundle ID | org.wordpress.alpha | |
| Commit | 62a74d9 | |
| Installation URL | 5mlg079n75o9g |
Contributor
|
| App Name | Jetpack | |
| Configuration | Release-Alpha | |
| Build Number | 33901 | |
| Version | PR #25932 | |
| Bundle ID | com.jetpack.alpha | |
| Commit | 62a74d9 | |
| Installation URL | 0ucugq3njukvg |
jkmassel
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Aug 24, 2026
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Aug 26, 2026
…mobile#25941) The test built its context from NSManagedObjectModel.mergedModel(from: [Bundle.main]), loading a second copy of the current schema. Every loaded model registers its entities in Core Data's process-global class-to-entity table, so this left two entity descriptions claiming ReaderPost, Blog, and the other subclasses. When a later test in the same process saved, Core Data's change processing hit the ambiguity and crashed with "-[__NSCFSet addObject:]: attempt to insert nil", failing unrelated tests depending on execution order. Use ContextManager.forTesting(), which reuses the single process-wide current model, and pass that stack straight to SharedDataIssueSolver. This completes the deduplication started in wordpress-mobile#25932, which covered DataMigratorTests but not this call site.
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The migration tests load previous versions of Core Data models, which lead to the same Core Data type names (
Blog,Post, etc) can be resolved is mapped to different in-memory representation.This PR made two main changes:
neutralizingEntityClassesto avoid mapping multiple Core Data type names. This function is duplicated in different modules, because it's small and narrow enough that I feel it's an overkill to share it.