[types] Add typings for slug

packages/@sanity/types/src/index.ts

@@ -1,3 +1,4 @@
+export * from './slug'
 export * from './paths'
 export * from './schema'
 export * from './documents'

packages/@sanity/types/src/schema/types.ts

@@ -1,5 +1,7 @@
 // Note: INCOMPLETE, but it's a start
 
+import {SlugOptions} from '../slug'
+
 export interface Schema {
   name: string
   get: (name: string) => SchemaType
@@ -49,6 +51,11 @@ export interface BlockSchemaType extends ObjectSchemaType {
   of?: SchemaType[]
 }
 
+export interface SlugSchemaType extends ObjectSchemaType {
+  jsonType: 'object'
+  options?: SlugOptions
+}
+
 export interface ObjectField<T extends SchemaType = SchemaType> {
   name: string
   fieldset?: string

packages/@sanity/types/src/slug/index.ts

@@ -0,0 +1 @@
+export * from './types'

packages/@sanity/types/src/slug/types.ts

@@ -0,0 +1,42 @@
+import {SlugSchemaType} from '../schema'
+import {SanityDocument} from '../documents'
+import {Path} from '../paths'
+
+export interface Slug {
+  _type: 'slug'
+  current: string
+}
+
+export type SlugParent = Record<string, unknown> | Record<string, unknown>[]
+
+export interface SlugSourceOptions {
+  parentPath: Path
+  parent: SlugParent
+}
+
+export type SlugSourceFn = (
+  document: SanityDocument,
+  options: SlugSourceOptions
+) => string | Promise<string>
+
+export type SlugifierFn = (source: string, schemaType: SlugSchemaType) => string | Promise<string>
+
+export interface SlugUniqueOptions {
+  parent: SlugParent
+  type: SlugSchemaType
+  document: SanityDocument
+  defaultIsUnique: UniqueCheckerFn
+  path: Path
+}
+
+export type UniqueCheckerFn = (
+  slug: string,
+  options: SlugUniqueOptions
+) => boolean | Promise<boolean>
+
+export interface SlugOptions {
+  source?: string | Path | SlugSourceFn
+  maxLength?: number
+  slugify?: SlugifierFn
+  isUnique?: UniqueCheckerFn
+}