@studnicky/known-types-outside-adapters

Bans any and unknown types outside the adapters layer of a hexagonal architecture. Adapters are the only layer permitted to hold untyped intake data — their job is converting it into known shapes at the boundary; every other layer must consume already-converted, known types. The rule resolves each file's layer the same way layer-import-boundary does (via layers/sourceRoot), then — for any file not resolved to the adapters layer (configurable via adapterLayerName, default "adapters") — reports every TSAnyKeyword and TSUnknownKeyword node. Files outside the configured layer tree are never checked, and a file resolved to the adapters layer is fully exempt; notably, infrastructure — which can otherwise import any configured layer — is still bound by this restriction. This rule is typically wired together with layer-import-boundary, domain-purity, and adapter-only-import via the HexagonalSuite.create({...}) factory export, since all four share the same layers/sourceRoot configuration — but it is fully usable and configurable on its own.

Fixable: No · Options: Yes · Suggested severity: error

Options

Name	Type	Default	Description
layers	string[]	(required)	Ordered list of enforced layer names, e.g. ["domain", "ports", "application", "adapters", "infrastructure"].
sourceRoot	string	(required)	Path segment(s) after which the layer name appears, e.g. "src".
aliasPrefixes	object	undefined	Map of path-alias prefixes (e.g. "@domain/") to their layer name.
allowedImports	object	undefined	Override of the default allow-matrix: source layer name → list of layers it may import from.
adapterLayerName	string	"adapters"	Name of the layer exempted from this ban — the layer responsible for converting untyped intake data into known shapes.

✗ Incorrect

// domain-layer file (/repo/src/domain/user/User.ts) using 'any' — forbidden
function parse(input: any): void {}

// domain-layer file using 'unknown' — forbidden
function parse(input: unknown): void {}

// infrastructure-layer file using 'any' — forbidden despite infrastructure
// otherwise being able to import any configured layer
function parse(input: any): void {}

// domain-layer file using both 'any' and 'unknown' — both flagged
let value: any; let other: unknown;

✓ Correct

// adapters-layer file (/repo/src/adapters/HttpAdapter.ts) using 'any'/'unknown'
// — allowed, adapters are exempt
function parse(input: any): unknown { return input; }

// domain-layer file using only known types — not flagged
function parse(input: string): number { return input.length; }

// file outside the configured layer tree (/repo/scripts/build.ts) — out of scope
function parse(input: any): void {}