feat: add support for parsing more RDF formats using rdf-parse

src/storage/conversion/RdfToQuadConverter.ts

@@ -0,0 +1,41 @@
+import { PassThrough } from 'stream';
+import rdfParser from 'rdf-parse';
+import { Representation } from '../../ldp/representation/Representation';
+import { RepresentationMetadata } from '../../ldp/representation/RepresentationMetadata';
+import { CONTENT_TYPE_QUADS, DATA_TYPE_QUAD } from '../../util/ContentTypes';
+import { UnsupportedHttpError } from '../../util/errors/UnsupportedHttpError';
+import { checkRequest } from './ConversionUtil';
+import { RepresentationConverter, RepresentationConverterArgs } from './RepresentationConverter';
+
+/**
+ * Converts most major RDF serializations to `internal/quads`.
+ */
+export class RdfToQuadConverter extends RepresentationConverter {
+  public async canHandle(input: RepresentationConverterArgs): Promise<void> {
+    checkRequest(input, await rdfParser.getContentTypes(), [ CONTENT_TYPE_QUADS ]);
+  }
+
+  public async handle(input: RepresentationConverterArgs): Promise<Representation> {
+    return this.rdfToQuads(input.representation, input.identifier.path);
+  }
+
+  private rdfToQuads(representation: Representation, baseIRI: string): Representation {
+    const metadata: RepresentationMetadata = { ...representation.metadata, contentType: CONTENT_TYPE_QUADS };
+
+    // Catch parsing errors and emit correct error
+    // Node 10 requires both writableObjectMode and readableObjectMode
+    const errorStream = new PassThrough({ writableObjectMode: true, readableObjectMode: true });
+    const data = rdfParser.parse(representation.data, {
+      contentType: representation.metadata.contentType as string,
+      baseIRI,
+    });
+    data.pipe(errorStream);
+    data.on('error', (error): boolean => errorStream.emit('error', new UnsupportedHttpError(error.message)));
+
+    return {
+      dataType: DATA_TYPE_QUAD,
+      data: errorStream,
+      metadata,
+    };
+  }
+}