Shared settings

Three settings describe your project, not a rule, so they are declared once under settings["dl-effect"] in the oxlint config and every rule that uses them reads them from there. Their defaults fit a Node CLI; on another layout (Next.js, a monorepo) set them before reading the warnings.

The settings

Setting	Default	Used by
entryFiles: the files allowed to run Effects and import adapters	**/main.ts, **/cli.ts, **/bin/**	run-only-in-runner, adapter-import-boundary
testFiles: the test files, exempt from the rules that tests legitimately break	**/*.test.*, **/*.spec.*, **/__tests__/**, **/test/**, **/tests/**	run-only-in-runner, adapter-import-boundary, no-effect-promise, provide-named-layer, no-provide-on-definition, split-success-path-from-error-handling, all-errors-handled-at-boundary, anti-slop-no-service-constructor-imports, no-throw-or-primitive-failure, single-style-per-function, prefer-effect-vitest
discriminants: the fields that discriminate a closed union	_tag	no-manual-discriminant-comparison, no-manual-discriminant-construction

The default entryFiles leave out index.ts on purpose: it is usually a barrel, and exempting it would let adapters reach the rest of the application through re-exports.

Most rules skip testFiles entirely. Three use them differently: no-throw-or-primitive-failure skips only primitive failures there, single-style-per-function treats their helpers like tests, and prefer-effect-vitest checks only them. A helper directory such as src/testing/ does not count as tests: it is support code.

Add to discriminants the fields your unions discriminate on, such as type or kind.

File globs are matched against the path relative to oxlint’s working directory, with / on every platform.

Setting a value

Set one only where its default does not fit: it replaces the default instead of extending it. To extend a default in a TypeScript config, spread the one the package exports: defaultEntryFiles, defaultTestFiles or defaultDiscriminants. A JSON config cannot import them: copy the default from the table above. An unknown key or a value that is not an array of strings stops the lint with an error, so a typo is never silently ignored.

import { defaultTestFiles } from "@doubleloop-io/oxlint-plugin-effect"
import dlEffectAll from "@doubleloop-io/oxlint-plugin-effect/presets/all"
import { defineConfig } from "oxlint"

export default defineConfig({
    extends: [dlEffectAll],
    settings: {
        "dl-effect": {
            entryFiles: ["apps/web/src/app/**/route.ts", "apps/web/src/runtime.ts"],
            testFiles: [...defaultTestFiles, "e2e/**"],
        },
    },
})

{
    "extends": ["./node_modules/@doubleloop-io/oxlint-plugin-effect/dist/presets/all.json"],
    "settings": {
        "dl-effect": {
            "entryFiles": ["apps/web/src/app/**/route.ts", "apps/web/src/runtime.ts"],
            "testFiles": [
                "**/*.test.*",
                "**/*.spec.*",
                "**/__tests__/**",
                "**/test/**",
                "**/tests/**",
                "e2e/**"
            ]
        }
    }
}

Where settings go

Settings belong to the config that lints: oxlint does not inherit them from a preset in extends, and rejects them in overrides. For a value that differs by group of files, use overrides on the rules instead.