feat: allow custom context parser as a parameter to the parser & fix …

…context mutations

lib/JsonLdParser.ts

@@ -1,7 +1,7 @@
 import * as RDF from "@rdfjs/types";
 // tslint:disable-next-line:no-var-requires
 const Parser = require('@bergos/jsonparse');
-import {ERROR_CODES, ErrorCoded, IDocumentLoader, JsonLdContext, Util as ContextUtil} from "jsonld-context-parser";
+import {ERROR_CODES, ErrorCoded, IDocumentLoader, JsonLdContext, Util as ContextUtil, ContextParser} from "jsonld-context-parser";
 import {PassThrough, Transform, Readable} from "readable-stream";
 import {EntryHandlerArrayValue} from "./entryhandler/EntryHandlerArrayValue";
 import {EntryHandlerContainer} from "./entryhandler/EntryHandlerContainer";
@@ -672,4 +672,8 @@ export interface IJsonLdParserOptions {
    * Defaults to false.
    */
   rdfstarReverseInEmbedded?: boolean;
+  /**
+   * The the context parser to use.
+   */
+  contextParser?: ContextParser;
 }

lib/ParsingContext.ts

@@ -86,7 +86,7 @@ export class ParsingContext {
 
   constructor(options: IParsingContextOptions) {
     // Initialize settings
-    this.contextParser = new ContextParser({ documentLoader: options.documentLoader, skipValidation: options.skipContextValidation });
+    this.contextParser = options.contextParser ?? new ContextParser({ documentLoader: options.documentLoader, skipValidation: options.skipContextValidation });
     this.streamingProfile = !!options.streamingProfile;
     this.baseIRI = options.baseIRI;
     this.produceGeneralizedRdf = !!options.produceGeneralizedRdf;
@@ -207,11 +207,11 @@ export class ParsingContext {
           || scopedContext[key]['@context']['@propagate']; // Propagation is true by default
 
         if (propagate !== false || i === keysOriginal.length - 1 - offset) {
-          contextRaw = scopedContext;
+          contextRaw = { ...scopedContext };
 
           // Clean up final context
           delete contextRaw['@propagate'];
-          contextRaw[key] = { ...contextRaw[key] };
+          contextRaw[key] = { ...contextRaw[key], };
           if ('@id' in contextKeyEntry) {
             contextRaw[key]['@id'] = contextKeyEntry['@id'];
           }

lib/entryhandler/keyword/EntryHandlerKeywordType.ts

@@ -69,18 +69,13 @@ export class EntryHandlerKeywordType extends EntryHandlerKeyword {
     if (hasTypedScopedContext) {
       // Do not propagate by default
       scopedContext = scopedContext.then((c) => {
-        if (!('@propagate' in c.getContextRaw())) {
-          c.getContextRaw()['@propagate'] = false;
-        }
+        let contextRaw = c.getContextRaw();
 
-        // Set the original context at this depth as a fallback
-        // This is needed when a context was already defined at the given depth,
-        // and this context needs to remain accessible from child nodes when propagation is disabled.
-        if (c.getContextRaw()['@propagate'] === false) {
-          c.getContextRaw()['@__propagateFallback'] = context.getContextRaw();
+        if (!('@propagate' in contextRaw) || contextRaw['@propagate'] === false) {
+          contextRaw = { ...contextRaw, '@propagate': false, '@__propagateFallback': context.getContextRaw() };
         }
 
-        return c;
+        return new JsonLdContextNormalized(contextRaw);
       });
 
       // Set the new context in the context tree

test/JsonLdParser-test.ts

@@ -6,14 +6,31 @@ import { EventEmitter } from 'events';
 import {DataFactory} from "rdf-data-factory";
 import each from 'jest-each';
 import "jest-rdf";
-import {ERROR_CODES, ErrorCoded, FetchDocumentLoader, JsonLdContextNormalized} from "jsonld-context-parser";
+import {ContextParser, ERROR_CODES, ErrorCoded, FetchDocumentLoader, IParseOptions, JsonLdContext, JsonLdContextNormalized} from "jsonld-context-parser";
 import {PassThrough} from "stream";
 import {Util} from "../lib/Util";
 import { ParsingContext } from '../lib/ParsingContext';
 import contexts, { MockedDocumentLoader } from '../mocks/contexts';
 
 const DF = new DataFactory<RDF.BaseQuad>();
 
+const deepFreeze = obj => {
+  Object.keys(obj).forEach(prop => {
+    if (typeof obj[prop] === 'object' && !Object.isFrozen(obj[prop])) deepFreeze(obj[prop]);
+  });
+  return Object.freeze(obj);
+};
+
+class FrozenContextParser extends ContextParser {
+  constructor(options: ConstructorParameters<typeof ContextParser>[0]) {
+    super(options);
+  }
+
+  public parse(context: JsonLdContext, options?: IParseOptions): Promise<JsonLdContextNormalized> {
+    return super.parse(context, options)// .then(deepFreeze);
+  }
+}
+
 describe('JsonLdParser', () => {
 
   describe('Parsing a Verifiable Credential', () => {
@@ -22,7 +39,11 @@ describe('JsonLdParser', () => {
     beforeEach(() => {
       parser = new JsonLdParser({
         dataFactory: DF,
-        documentLoader: new MockedDocumentLoader(),
+        // Use the frozen context parser so we can detect if there are
+        // any attempts at mutations in the unit tests
+        contextParser: new FrozenContextParser({
+          documentLoader: new MockedDocumentLoader()
+        }),
       })
     });