feat: Added resourceExists method to ResourceStore

* feat: added resourceExists method to ResourceStore

* Merge remote-tracking branch 'origin/main' into feat/add-resourceExists-method-to-ResourceStore

* fix: adapted to review

* fix: adapted to review

src/storage/BaseResourceStore.ts

@@ -11,6 +11,10 @@ import type { ResourceStore } from './ResourceStore';
  */
 /* eslint-disable @typescript-eslint/no-unused-vars */
 export class BaseResourceStore implements ResourceStore {
+  public async resourceExists(identifier: ResourceIdentifier, conditions?: Conditions): Promise<boolean> {
+    throw new NotImplementedHttpError();
+  }
+
   public async getRepresentation(identifier: ResourceIdentifier, preferences: RepresentationPreferences,
     conditions?: Conditions): Promise<Representation> {
     throw new NotImplementedHttpError();

src/storage/DataAccessorBasedStore.ts

@@ -67,6 +67,19 @@ export class DataAccessorBasedStore implements ResourceStore {
     this.auxiliaryStrategy = auxiliaryStrategy;
   }
 
+  public async resourceExists(identifier: ResourceIdentifier): Promise<boolean> {
+    try {
+      this.validateIdentifier(identifier);
+      await this.accessor.getMetadata(identifier);
+      return true;
+    } catch (error: unknown) {
+      if (NotFoundHttpError.isInstance(error)) {
+        return false;
+      }
+      throw error;
+    }
+  }
+
   public async getRepresentation(identifier: ResourceIdentifier): Promise<Representation> {
     this.validateIdentifier(identifier);
 

src/storage/LockingResourceStore.ts

@@ -35,6 +35,11 @@ export class LockingResourceStore implements AtomicResourceStore {
     this.strategy = strategy;
   }
 
+  public async resourceExists(identifier: ResourceIdentifier, conditions?: Conditions): Promise<boolean> {
+    return this.locks.withReadLock(this.getLockIdentifier(identifier),
+      async(): Promise<boolean> => this.source.resourceExists(identifier, conditions));
+  }
+
   public async getRepresentation(identifier: ResourceIdentifier, preferences: RepresentationPreferences,
     conditions?: Conditions): Promise<Representation> {
     return this.lockedRepresentationRun(this.getLockIdentifier(identifier),

src/storage/MonitoringStore.ts

@@ -19,6 +19,10 @@ export class MonitoringStore<T extends ResourceStore = ResourceStore>
     this.source = source;
   }
 
+  public async resourceExists(identifier: ResourceIdentifier, conditions?: Conditions): Promise<boolean> {
+    return this.source.resourceExists(identifier, conditions);
+  }
+
   public async getRepresentation(identifier: ResourceIdentifier, preferences: RepresentationPreferences,
     conditions?: Conditions): Promise<Representation> {
     return this.source.getRepresentation(identifier, preferences, conditions);

src/storage/PassthroughStore.ts

@@ -17,6 +17,15 @@ export class PassthroughStore<T extends ResourceStore = ResourceStore> implement
     this.source = source;
   }
 
+  public async resourceExists(identifier: ResourceIdentifier, conditions?: Conditions): Promise<boolean> {
+    return this.source.resourceExists(identifier, conditions);
+  }
+
+  public async getRepresentation(identifier: ResourceIdentifier, preferences: RepresentationPreferences,
+    conditions?: Conditions): Promise<Representation> {
+    return this.source.getRepresentation(identifier, preferences, conditions);
+  }
+
   public async addResource(container: ResourceIdentifier, representation: Representation,
     conditions?: Conditions): Promise<ResourceIdentifier> {
     return this.source.addResource(container, representation, conditions);
@@ -27,11 +36,6 @@ export class PassthroughStore<T extends ResourceStore = ResourceStore> implement
     return this.source.deleteResource(identifier, conditions);
   }
 
-  public async getRepresentation(identifier: ResourceIdentifier, preferences: RepresentationPreferences,
-    conditions?: Conditions): Promise<Representation> {
-    return this.source.getRepresentation(identifier, preferences, conditions);
-  }
-
   public async modifyResource(identifier: ResourceIdentifier, patch: Patch,
     conditions?: Conditions): Promise<ResourceIdentifier[]> {
     return this.source.modifyResource(identifier, patch, conditions);

src/storage/ResourceStore.ts

@@ -16,6 +16,15 @@ import type { Conditions } from './Conditions';
  * should those be relevant to the store.
  */
 export interface ResourceStore {
+
+  /**
+   * Check if a resource exists.
+   * @param identifier - Identifier of resource to check.
+   *
+   * @returns A promise resolving if the resource already exists
+   */
+  resourceExists: (identifier: ResourceIdentifier, conditions?: Conditions) => Promise<boolean>;
+
   /**
    * Retrieves a representation of a resource.
    * @param identifier - Identifier of the resource to read.

src/storage/RoutingResourceStore.ts

@@ -20,6 +20,11 @@ export class RoutingResourceStore implements ResourceStore {
     this.rule = rule;
   }
 
+  public async resourceExists(identifier: ResourceIdentifier, conditions?: Conditions):
+  Promise<boolean> {
+    return (await this.getStore(identifier)).resourceExists(identifier, conditions);
+  }
+
   public async getRepresentation(identifier: ResourceIdentifier, preferences: RepresentationPreferences,
     conditions?: Conditions): Promise<Representation> {
     return (await this.getStore(identifier)).getRepresentation(identifier, preferences, conditions);

src/storage/StoreUtil.ts

@@ -1,16 +0,0 @@
-import type { ResourceIdentifier } from '../ldp/representation/ResourceIdentifier';
-import { NotFoundHttpError } from '../util/errors/NotFoundHttpError';
-import type { ResourceStore } from './ResourceStore';
-
-export async function containsResource(store: ResourceStore, identifier: ResourceIdentifier): Promise<boolean> {
-  try {
-    const result = await store.getRepresentation(identifier, {});
-    result.data.destroy();
-    return true;
-  } catch (error: unknown) {
-    if (NotFoundHttpError.isInstance(error)) {
-      return false;
-    }
-    throw error;
-  }
-}

src/storage/routing/ConvertingRouterRule.ts

@@ -1,6 +1,5 @@
 import type { Representation } from '../../ldp/representation/Representation';
 import type { ResourceIdentifier } from '../../ldp/representation/ResourceIdentifier';
-import { containsResource } from '../../storage/StoreUtil';
 import type { ResourceStore } from '../ResourceStore';
 import type { PreferenceSupport } from './PreferenceSupport';
 import { RouterRule } from './RouterRule';
@@ -40,8 +39,7 @@ export class ConvertingRouterRule extends RouterRule {
         entry.supportChecker.supports({ identifier, representation }));
     } else {
       // No content-type given so we can only check if one of the stores has data for the identifier
-      store = await this.findStore(async(entry): Promise<boolean> =>
-        containsResource(entry.store, input.identifier));
+      store = await this.findStore(async(entry): Promise<boolean> => entry.store.resourceExists(input.identifier));
     }
     return store;
   }