Refactor

src/entities/catalog.ts

@@ -1,41 +1,32 @@
 import { QuerySpec } from ".";
-import { JsonLdId, JsonLdValue } from "./jsonld";
+import { JsonLdId } from "./jsonld";
 
 export interface CatalogRequest {
   providerUrl: string;
   querySpec?: QuerySpec;
 }
 
 export class Catalog extends JsonLdId {
-  "https://www.w3.org/ns/dcat/dataset": Dataset[];
 
   get datasets(): Dataset[] {
-    return this["https://www.w3.org/ns/dcat/dataset"].map((it) =>
-      Object.assign(new Dataset(), it),
-    );
+    return this.arrayOf(() => new Dataset(), 'dcat', 'dataset');
   }
 }
 
 export class Dataset extends JsonLdId {
-  "http://www.w3.org/ns/odrl/2/hasPolicy": Offer[];
 
   get offers(): Offer[] {
-    return this["http://www.w3.org/ns/odrl/2/hasPolicy"].map((it) =>
-      Object.assign(new Offer(), it),
-    );
+    return this.arrayOf(() => new Offer(), 'odrl', 'hasPolicy');
   }
 }
 
 export class Offer extends JsonLdId {
-  "http://www.w3.org/ns/odrl/2/target": JsonLdValue<string>[];
 
   get assetId(): string {
     return this.target;
   }
 
   get target(): string {
-    return this["http://www.w3.org/ns/odrl/2/target"].map((it) =>
-      Object.assign(new JsonLdValue(), it),
-    )[0].value;
+    return this.mandatoryValue('odrl', 'target');
   }
 }

src/entities/contract-agreement.ts

@@ -1,19 +1,24 @@
 import { Policy } from "./policy";
-import { JsonLdId, JsonLdValue } from "./jsonld"
+import { JsonLdId } from "./jsonld"
 
 export class ContractAgreement extends JsonLdId {
-  'https://w3id.org/edc/v0.0.1/ns/assetId': JsonLdValue<string>[];
-  consumerAgentId?: string;
-  contractEndDate?: number;
-  constractSigningDate?: number;
-  constractStartDate?: number;
+
   policy?: Policy;
-  providerAgentId?: string;
 
   get assetId(): string {
-    return this['https://w3id.org/edc/v0.0.1/ns/assetId']
-      .map(it => Object.assign(new JsonLdValue(), it))[0]
-      .value
+    return this.mandatoryValue('edc', 'assetId');
+  }
+
+  get providerId(): string {
+    return this.mandatoryValue('edc', 'providerId');
+  }
+
+  get consumerId(): string {
+    return this.mandatoryValue('edc', 'providerId');
+  }
+
+  get contractSigningDate(): number {
+    return this.mandatoryValue('edc', 'providerId');
   }
 
 }

src/entities/jsonld.ts

@@ -1,4 +1,38 @@
-export class JsonLdId {
+import { EDC_CONTEXT } from "./context";
+
+export class JsonLdObject {
+
+  [propertyName: string]: any;
+
+  mandatoryValue<T>(prefix: string, name: string): T {
+    return this.optionalValue(prefix, name)!;
+  }
+
+  optionalValue<T>(prefix: string, name: string): T | undefined {
+    var namespace = this.getNamespaceUrl(prefix);
+    return (this[`${namespace}${name}`] as JsonLdValue<T>[])
+      ?.map(it => Object.assign(new JsonLdValue(), it))
+      ?.at(0)?.value;
+  }
+
+  arrayOf<T extends Object>(newInstance: (() => T), prefix: string, name: string): T[] {
+    var namespace = this.getNamespaceUrl(prefix);
+    return (this[`${namespace}${name}`] as T[]).map(it =>
+      Object.assign(newInstance(), it),
+    );
+  }
+
+  private getNamespaceUrl(prefix: string): string {
+    switch (prefix) {
+      case 'edc': return EDC_CONTEXT;
+      case 'odrl': return 'http://www.w3.org/ns/odrl/2/';
+      case 'dcat': return 'https://www.w3.org/ns/dcat/';
+      default: throw new Error(`JSON-LD context ${prefix} not supported`);
+    }
+  }
+}
+
+export class JsonLdId extends JsonLdObject {
   '@id': string;
 
   get id() {

src/entities/policy.ts

@@ -21,7 +21,7 @@ export interface Policy {
   obligations?: Duty[];
   permissions?: Permission[];
   prohibitions?: Prohibition[];
-  traget?: string;
+  target?: string;
 }
 
 export class PolicyDefinition extends JsonLdId {

tests/test-utils.ts

@@ -118,10 +118,11 @@ export async function createContractNegotiation(
     providerUrl: providerContext.protocol,
   });
 
+
   const offer = catalog
     .datasets
-    .flatMap((it) => it.offers)
-    .find((offer) => offer.assetId === assetId)!;
+    .flatMap(it => it.offers)
+    .find(offer => offer.assetId === assetId)!;
 
   // Initiate contract negotiation on the consumer's side
   const idResponse = await client.management.initiateContractNegotiation(