Annotations and tooling

mobx_codegen generates accessors and action wrappers; mobx supplies the runtime they call. Keep them as separate dependencies: the runtime in dependencies, the generator and build_runner in dev_dependencies.

Control generated state

Declaration	Meaning
@observable	Track reads and writes to a field
@readonly	Generate public read access to a private observable field
@computed	Derive a value from observable reads in a getter
@action	Wrap a method's writes in an action; async methods use AsyncAction
@alwaysNotify	Use observableAlwaysNotEqual to notify even for equal assignments
@MakeObservable(equals: ...)	Select a top-level or static equality comparer
@ComputedMethod(keepAlive: true)	Retain a computed beyond ordinary observation; use deliberately
@StoreConfig(hasToString: false)	Disable the generated store string representation

bool sameId(Item? a, Item? b) => a?.id == b?.id;

// Inside a generated Store; Item is your domain type.
@MakeObservable(equals: sameId)
Item? selected;

@readonly
int _revision = 0;

An equality comparer returns true for equal values, suppressing notification. alwaysNotify deliberately returns false. Deep comparison is an option for generated values; it is not recursive observation and may be expensive for large collections. Prefer equality that matches the value's meaning.

Generate and inspect

Run dart run build_runner build --delete-conflicting-outputs. Keep the part declaration and mixin name aligned with the file and store class. Do not hand-edit generated .g.dart files. Build output explains the generated structure.

StoreGenerator is the exported generator entry point for build integrations. Ordinary app code uses annotations, not the generator object. build.yaml defines the builder integration. The package version constants expose the installed package version for diagnostics; alias imports if reading several packages' identically named constants.

Lint support

mobx_lint supplies a custom-lint plugin and an assist for wrapping widgets with Observer. Enable the analyzer plugin and configure custom_lint in the consuming project's development toolchain. Its plugin entry point is tooling, not a reactive application API. The lint package is resolved separately in this repository because its analyzer constraints differ from the generator workspace.

Keep SDK and generator upgrades coordinated. Run generator tests and regenerate examples whenever changing analyzer or source-generation dependencies.

The secondary package:mobx_codegen/builder.dart entry point exports storeGenerator(BuilderOptions), which creates the SharedPartBuilder consumed by build_runner. The isolated package:mobx_lint/mobx_lint.dart entry point exports createPlugin(). The lint reference documents that tooling boundary; neither belongs in a Flutter application's runtime imports.