feat: Specifiy constants in separate file

src/ldp/http/SimpleBodyParser.ts

@@ -1,4 +1,5 @@
 import { BodyParser } from './BodyParser';
+import { DATA_TYPE_QUAD } from '../../util/ContentTypes';
 import { HttpRequest } from '../../server/HttpRequest';
 import { PassThrough } from 'stream';
 import { QuadRepresentation } from '../representation/QuadRepresentation';
@@ -53,7 +54,7 @@ export class SimpleBodyParser extends BodyParser {
     data.on('error', (error): boolean => errorStream.emit('error', new UnsupportedHttpError(error.message)));
 
     return {
-      dataType: 'quad',
+      dataType: DATA_TYPE_QUAD,
       data: errorStream,
       metadata,
     };

src/ldp/http/SimpleResponseWriter.ts

@@ -1,3 +1,4 @@
+import { DATA_TYPE_BINARY } from '../../util/ContentTypes';
 import { HttpError } from '../../util/errors/HttpError';
 import { HttpResponse } from '../../server/HttpResponse';
 import { ResponseDescription } from '../operations/ResponseDescription';
@@ -11,8 +12,8 @@ export class SimpleResponseWriter extends ResponseWriter {
   public async canHandle(input: { response: HttpResponse; result: ResponseDescription | Error }): Promise<void> {
     if (!(input.result instanceof Error)) {
       const dataType = input.result.body?.dataType;
-      if (dataType && dataType !== 'binary' && dataType !== 'string') {
-        throw new UnsupportedHttpError('Only string or binary results are supported.');
+      if (dataType && dataType !== DATA_TYPE_BINARY) {
+        throw new UnsupportedHttpError('Only binary results are supported.');
       }
     }
   }

src/storage/SimpleResourceStore.ts

@@ -11,6 +11,7 @@ import { ResourceStore } from './ResourceStore';
 import streamifyArray from 'streamify-array';
 import { StreamWriter } from 'n3';
 import { UnsupportedMediaTypeHttpError } from '../util/errors/UnsupportedMediaTypeHttpError';
+import { CONTENT_TYPE_QUADS, DATA_TYPE_BINARY, DATA_TYPE_QUAD } from '../util/ContentTypes';
 
 /**
  * Resource store storing its data as Quads in an in-memory map.
@@ -113,7 +114,7 @@ export class SimpleResourceStore implements ResourceStore {
    * @returns Promise of array of Quads pulled from the stream.
    */
   private async parseRepresentation(representation: Representation): Promise<Quad[]> {
-    if (representation.dataType !== 'quad') {
+    if (representation.dataType !== DATA_TYPE_QUAD) {
       throw new UnsupportedMediaTypeHttpError('SimpleResourceStore only supports quad representations.');
     }
     return arrayifyStream(representation.data);
@@ -134,7 +135,7 @@ export class SimpleResourceStore implements ResourceStore {
    */
   private generateRepresentation(data: Quad[], preferences: RepresentationPreferences): Representation {
     // Always return turtle unless explicitly asked for quads
-    if (preferences.type?.some((preference): boolean => preference.value.includes('internal/quads'))) {
+    if (preferences.type?.some((preference): boolean => preference.value.includes(CONTENT_TYPE_QUADS))) {
       return this.generateQuadRepresentation(data);
     }
     return this.generateBinaryRepresentation(data);
@@ -148,7 +149,7 @@ export class SimpleResourceStore implements ResourceStore {
    */
   private generateBinaryRepresentation(data: Quad[]): BinaryRepresentation {
     return {
-      dataType: 'binary',
+      dataType: DATA_TYPE_BINARY,
       data: streamifyArray([ ...data ]).pipe(new StreamWriter({ format: 'text/turtle' })),
       metadata: { raw: [], profiles: [], contentType: 'text/turtle' },
     };
@@ -162,7 +163,7 @@ export class SimpleResourceStore implements ResourceStore {
    */
   private generateQuadRepresentation(data: Quad[]): QuadRepresentation {
     return {
-      dataType: 'quad',
+      dataType: DATA_TYPE_QUAD,
       data: streamifyArray([ ...data ]),
       metadata: { raw: [], profiles: []},
     };

src/storage/patch/SimpleSparqlUpdatePatchHandler.ts

@@ -11,6 +11,7 @@ import { someTerms } from 'rdf-terms';
 import { SparqlUpdatePatch } from '../../ldp/http/SparqlUpdatePatch';
 import { Store } from 'n3';
 import { UnsupportedHttpError } from '../../util/errors/UnsupportedHttpError';
+import { CONTENT_TYPE_QUADS, DATA_TYPE_QUAD } from '../../util/ContentTypes';
 
 /**
  * PatchHandler that supports specific types of SPARQL updates.
@@ -55,7 +56,7 @@ export class SimpleSparqlUpdatePatchHandler extends PatchHandler {
 
     const lock = await this.locker.acquire(input.identifier);
     const quads = await this.source.getRepresentation(input.identifier,
-      { type: [{ value: 'internal/quads', weight: 1 }]});
+      { type: [{ value: CONTENT_TYPE_QUADS, weight: 1 }]});
     const store = new Store<BaseQuad>();
     const importEmitter = store.import(quads.data);
     await new Promise((resolve, reject): void => {
@@ -66,11 +67,11 @@ export class SimpleSparqlUpdatePatchHandler extends PatchHandler {
     store.addQuads(inserts);
     const representation: Representation = {
       data: store.match() as Readable,
-      dataType: 'quad',
+      dataType: DATA_TYPE_QUAD,
       metadata: {
         raw: [],
         profiles: [],
-        contentType: 'internal/quads',
+        contentType: CONTENT_TYPE_QUADS,
       },
     };
     await this.source.setRepresentation(input.identifier, representation);

src/util/ContentTypes.ts

@@ -0,0 +1,4 @@
+export const DATA_TYPE_BINARY = 'binary';
+export const DATA_TYPE_QUAD = 'quad';
+
+export const CONTENT_TYPE_QUADS = 'internal/quads';