feat: ExtensionBasedMapper no longer throws if there is no file

src/storage/accessors/FileDataAccessor.ts

@@ -350,8 +350,8 @@ export class FileDataAccessor implements DataAccessor {
         await fsPromises.unlink(oldLink.filePath);
       }
     } catch (error: unknown) {
-      // Ignore it if the file didn't exist yet
+      // Ignore it if the file didn't exist yet and couldn't be unlinked
-      if (!(error instanceof NotFoundHttpError)) {
+      if (!isSystemError(error) || error.code !== 'ENOENT') {
         throw error;
       }
     }

src/storage/mapping/ExtensionBasedMapper.ts

@@ -4,7 +4,6 @@ import * as mime from 'mime-types';
 import type { ResourceIdentifier } from '../../ldp/representation/ResourceIdentifier';
 import { getLoggerFor } from '../../logging/LogUtil';
 import { APPLICATION_OCTET_STREAM, TEXT_TURTLE } from '../../util/ContentTypes';
-import { NotFoundHttpError } from '../../util/errors/NotFoundHttpError';
 import { NotImplementedHttpError } from '../../util/errors/NotImplementedHttpError';
 import {
   encodeUriPathComponents,
@@ -98,22 +97,18 @@ export class ExtensionBasedMapper implements FileIdentifierMapper {
         );
       } catch {
         // Parent folder does not exist (or is not a folder)
-        this.logger.warn(`No parent folder for ${identifier.path} found at ${folder}`);
-        throw new NotFoundHttpError();
       }
 
-      // File doesn't exist
+      // Matching file found
-      if (!fileName) {
+      if (fileName) {
-        this.logger.warn(`File for URL ${identifier.path} does not exist in ${folder}`);
+        filePath = joinPath(folder, fileName);
-        throw new NotFoundHttpError();
       }
 
-      filePath = joinPath(folder, fileName);
       this.logger.info(`The path for ${identifier.path} is ${filePath}`);
       return {
         identifier,
         filePath,
-        contentType: this.getContentTypeFromExtension(fileName),
+        contentType: this.getContentTypeFromExtension(filePath),
       };
     }
 

src/storage/mapping/FileIdentifierMapper.ts

@@ -29,7 +29,8 @@ export interface FileIdentifierMapper {
   mapFilePathToUrl: (filePath: string, isContainer: boolean) => Promise<ResourceLink>;
   /**
    * Maps the given resource identifier / URL to a file path.
-   * Determines the content-type if no content-type was provided.
+   * Determines the content-type if no content-type was provided by finding the corresponding file.
+   * If there is no corresponding file a file path will be generated.
    * For containers the content-type input gets ignored.
    * @param identifier - The input identifier.
    * @param contentType - The (optional) content-type of the resource.

test/unit/storage/accessors/FileDataAccessor.test.ts

@@ -223,20 +223,27 @@ describe('A FileDataAccessor', (): void => {
       });
     });
 
+    it('does not try to update the content-type if there is no original file.', async(): Promise<void> => {
+      metadata.identifier = DataFactory.namedNode(`${base}resource.txt`);
+      metadata.contentType = 'text/turtle';
+      metadata.add('new', 'metadata');
+      await expect(accessor.writeDocument({ path: `${base}resource.txt` }, data, metadata))
+        .resolves.toBeUndefined();
+      expect(cache.data).toEqual({
+        'resource.txt$.ttl': 'data',
+        'resource.txt.meta': expect.stringMatching(`<${base}resource.txt> <new> "metadata".`),
+      });
+    });
+
     it('throws an error if there is an issue deleting the original file.', async(): Promise<void> => {
       cache.data = { 'resource$.ttl': '<this> <is> <data>.' };
       jest.requireMock('fs').promises.unlink = (): any => {
         const error = new Error('error') as SystemError;
-        error.code = 'ENOENT';
+        error.code = 'EISDIR';
         error.syscall = 'unlink';
         throw error;
       };
 
-      // `unlink` throwing ENOENT should not be an issue if the content-type does not change
-      metadata.contentType = 'text/turtle';
-      await expect(accessor.writeDocument({ path: `${base}resource` }, data, metadata))
-        .resolves.toBeUndefined();
-
       metadata.contentType = 'text/plain';
       await expect(accessor.writeDocument({ path: `${base}resource` }, data, metadata))
         .rejects.toThrow(new Error('error'));

test/unit/storage/mapping/ExtensionBasedMapper.test.ts

@@ -50,16 +50,24 @@ describe('An ExtensionBasedMapper', (): void => {
         .rejects.toThrow(new BadRequestHttpError('Identifiers cannot contain a dollar sign before their extension'));
     });
 
-    it('throws 404 when looking in a folder that does not exist.', async(): Promise<void> => {
+    it('determines content-type by extension when looking in a folder that does not exist.', async(): Promise<void> => {
       fsPromises.readdir.mockImplementation((): void => {
         throw new Error('does not exist');
       });
-      await expect(mapper.mapUrlToFilePath({ path: `${base}no/test.txt` })).rejects.toThrow(NotFoundHttpError);
+      await expect(mapper.mapUrlToFilePath({ path: `${base}no/test.txt` })).resolves.toEqual({
+        identifier: { path: `${base}no/test.txt` },
+        filePath: `${rootFilepath}no/test.txt`,
+        contentType: 'text/plain',
+      });
     });
 
-    it('throws 404 when looking for a file that does not exist.', async(): Promise<void> => {
+    it('determines content-type by extension when looking for a file that does not exist.', async(): Promise<void> => {
       fsPromises.readdir.mockReturnValue([ 'test.ttl' ]);
-      await expect(mapper.mapUrlToFilePath({ path: `${base}test.txt` })).rejects.toThrow(NotFoundHttpError);
+      await expect(mapper.mapUrlToFilePath({ path: `${base}test.txt` })).resolves.toEqual({
+        identifier: { path: `${base}test.txt` },
+        filePath: `${rootFilepath}test.txt`,
+        contentType: 'text/plain',
+      });
     });
 
     it('determines the content-type based on the extension.', async(): Promise<void> => {