@systemfsoftware/oxlint-plugin-effect-schema

Oxlint rules for Effect Schema declarations — how a schema is declared, and what an authored schema property test is allowed to assert.

Rules

| Rule | What it enforces | | ---------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | ban-effect-schema-imports | Import Schema from effect, never from the deprecated @effect/schema package. | | ban-data-taggederror | Use Schema.TaggedError, never Data.TaggedError. | | no-manual-tag-member | A type alias, interface, or type literal must not declare a _tag property signature; derive the type from TaggedStruct / TaggedError with Schema.Type, or inherit it from a tag carrier. | | no-manual-tag-property | A class must not declare its own _tag; use TaggedClass / TaggedError. | | no-schema-law-duplicate | A *.schema.property.test.ts may state only refusals — never ruleOfSchemas, Schema.equivalence, Schema.encodedSchema. | | schema-declaration-location | A schema declaration (a class extending a Schema factory, or a module-scope const initialized to a Schema.<member>(...) call) must live in a *.schema.ts file or the <stem>.workflow.ts that owns it. | | schema-file-exports-schemas-only | A *.schema.ts may export nothing but schemas: schema declarations plus the type vocabulary (type aliases, enums) the schemas are built from. An exported codec const (S.encodeSync, S.decodeSync, S.toArbitrary, ...) and every re-export form are banned — the file declares its schemas, the caller applies them at the point of use. |

Why a schema property test exists at all

ruleOfSchemas generates a round-trip pair for every exported schema, and draws every input from that schema's own arbitrary. So each input already satisfies the refinement under test, and the law reduces to "values built to match the refinement match the refinement". No generated law can reach rejection.

That gap — and only that gap — is what a *.schema.property.test.ts is for. Its generators must be derived from the domain contract, never from the refinement literal, or the test inherits the same circularity it exists to escape.

Enrollment

Turned on by @systemfsoftware/oxlint-config/base, which spreads configs.recommended.rules.

Testing

Each rule ships a RuleTester suite at src/rules/__tests__/<rule>.test.ts, with 100% mutation coverage required.