public commit

app/src/data/relations/OneToOneRelation.ts

@@ -0,0 +1,77 @@
+import type { Entity, EntityManager } from "../entities";
+import { ManyToOneRelation, type ManyToOneRelationConfig } from "./ManyToOneRelation";
+import type { MutationInstructionResponse } from "./RelationMutator";
+import { type RelationType, RelationTypes } from "./relation-types";
+
+/**
+ * Both source and target receive a mapping field
+ * @todo: determine if it should be removed
+ */
+export type OneToOneRelationConfig = ManyToOneRelationConfig;
+
+/* export type OneToOneRelationConfig = {
+   mappedBy?: string; // author|users
+   inversedBy?: string; // posts
+   required?: boolean;
+}; */
+
+export class OneToOneRelation extends ManyToOneRelation {
+   constructor(source: Entity, target: Entity, config?: OneToOneRelationConfig) {
+      const { mappedBy, inversedBy, required } = config || {};
+      super(source, target, {
+         mappedBy,
+         inversedBy,
+         sourceCardinality: 1,
+         required
+      });
+   }
+
+   override type(): RelationType {
+      return RelationTypes.OneToOne;
+   }
+
+   /**
+    * One-to-one relations are not listable in either direction
+    */
+   override isListableFor(): boolean {
+      return false;
+   }
+
+   // need to override since it inherits manytoone
+   override async $set(
+      em: EntityManager<any>,
+      key: string,
+      value: object
+   ): Promise<MutationInstructionResponse> {
+      throw new Error("$set is not allowed");
+   }
+
+   override async $create(
+      em: EntityManager<any>,
+      key: string,
+      value: unknown
+   ): Promise<void | MutationInstructionResponse> {
+      if (value === null || typeof value !== "object") {
+         throw new Error(`Invalid value for relation field "${key}" given, expected object.`);
+      }
+
+      const target = this.other(this.source.entity).entity;
+      const helper = this.helper(this.source.entity.name);
+      const info = helper.getMutationInfo();
+      const primary = info.primary;
+      const local_field = info.local_field;
+      if (!info.$create || !primary || !local_field) {
+         throw new Error(`Cannot perform $create for relation "${key}"`);
+      }
+
+      // create the relational entity
+      try {
+         const { data } = await em.mutator(target).insertOne(value);
+
+         const retrieved_value = data[primary];
+         return [local_field, retrieved_value] satisfies MutationInstructionResponse;
+      } catch (e) {
+         throw new Error(`Error performing $create on "${target.name}".`);
+      }
+   }
+}