Add preliminary resource relationship support

Define resource methods for adding relationships to other resources.

packages/core/src/common/resource.ts

@@ -13,12 +13,19 @@ export const PATCH_CONTENT_MAP_TYPE: Record<PatchContentType, CanPatchSpec> = {
 
 type CanPatchObject = Record<CanPatchSpec, boolean>;
 
+export interface Relationship<SubjectSchema extends v.BaseSchema, ObjectSchema extends v.BaseSchema> {
+	objectResource: Resource<BaseResourceType & { schema: ObjectSchema }>,
+	name: string;
+	// points to object ID
+	subjectAttr: string;
+}
+
 export interface ResourceState<
 	ItemName extends string = string,
 	RouteName extends string = string
 > {
 	shared: Map<string, unknown>;
-	relationships: Set<Resource>;
+	relationships: Map<string, Relationship<any, any>>;
 	itemName: ItemName;
 	routeName: RouteName;
 	canCreate: boolean;
@@ -52,12 +59,17 @@ export interface Resource<ResourceType extends BaseResourceType = BaseResourceTy
 	canPatch(b?: CanPatch): this;
 	canEmplace(b?: boolean): this;
 	canDelete(b?: boolean): this;
-	relatedTo<RelatedSchema extends v.BaseSchema>(resource: Resource<ResourceType & { schema: RelatedSchema }>): this;
+	relatesTo<RelatedSchema extends v.BaseSchema>(
+		resource: Resource<ResourceType & { schema: RelatedSchema }>,
+		relationshipParams: Relationship<ResourceType['schema'], RelatedSchema>,
+	): this;
 	dataSource?: DataSource;
 	id<NewIdAttr extends ResourceType['idAttr'], TheIdSchema extends ResourceType['idSchema']>(
 		newIdAttr: NewIdAttr,
 		params: ResourceIdConfig<TheIdSchema>
 	): Resource<ResourceType & { idAttr: NewIdAttr, idSchema: TheIdSchema }>;
+	addMetadata(id: string, value: unknown): this;
+	setMetadata(id: string, value: unknown): this;
 	createdAt<NewCreatedAtAttr extends ResourceType['createdAtAttr']>(n: NewCreatedAtAttr): Resource<ResourceType & { createdAtAttr: NewCreatedAtAttr }>;
 	updatedAt<NewUpdatedAtAttr extends ResourceType['updatedAtAttr']>(n: NewUpdatedAtAttr): Resource<ResourceType & { updatedAtAttr: NewUpdatedAtAttr }>;
 }
@@ -65,7 +77,7 @@ export interface Resource<ResourceType extends BaseResourceType = BaseResourceTy
 export const resource = <ResourceType extends BaseResourceType = BaseResourceType>(schema: ResourceType['schema']): Resource<ResourceType> => {
 	const resourceState = {
 		shared: new Map(),
-		relationships: new Set<Resource>(),
+		relationships: new Map<string, Relationship<any, any>>(),
 		canCreate: false,
 		canFetchCollection: false,
 		canFetchItem: false,
@@ -131,10 +143,14 @@ export const resource = <ResourceType extends BaseResourceType = BaseResourceTyp
 			resourceState.shared.set('idConfig', config);
 			return this;
 		},
-		fullText(attrName: string) {
-			const fullTextAttrs = (resourceState.shared.get('fullText') ?? new Set()) as Set<string>;
-			fullTextAttrs.add(attrName);
-			resourceState.shared.set('fullText', fullTextAttrs);
+		addMetadata(key: string, value: unknown) {
+			const fullTextAttrs = (resourceState.shared.get(key) ?? new Set()) as Set<unknown>;
+			fullTextAttrs.add(value);
+			this.setMetadata(key, fullTextAttrs);
+			return this;
+		},
+		setMetadata(key: string, value: unknown) {
+			resourceState.shared.set(key, value);
 			return this;
 		},
 		name<NewName extends ResourceType['name']>(n: NewName) {
@@ -154,8 +170,14 @@ export const resource = <ResourceType extends BaseResourceType = BaseResourceTyp
 		get schema() {
 			return schema;
 		},
-		relatedTo<RelatedSchema extends v.BaseSchema>(resource: Resource<ResourceType & { schema: RelatedSchema }>) {
-			resourceState.relationships.add(resource);
+		relatesTo<RelatedSchema extends v.BaseSchema>(
+			objectResource: Resource<ResourceType & { schema: RelatedSchema }>,
+			relationshipParams: Relationship<ResourceType['schema'], RelatedSchema>,
+		) {
+			resourceState.relationships.set(relationshipParams.name, {
+				...relationshipParams,
+				objectResource,
+			});
 			return this;
 		},
 		createdAt<NewCreatedAtAttr extends ResourceType['createdAtAttr']>(n: NewCreatedAtAttr) {