Where is verification for "loading an unknown type raises loading document failed"?

[ariutta]

I don't understand how this JS code passes this test. I don't see any code verifying that the content type of the response is correct.

(Moved the issue over from the json-ld.org repo: json-ld/json-ld.org#410)

[dlongley]

@ariutta,

The jsonld.js processor accepts content if it can be parsed as JSON:

jsonld.js/js/jsonld.js

Lines 276 to 293 in e63baf5

	try {
	if(!remoteDoc.document) {
	throw new JsonLdError(
	'No remote document found at the given URL.',
	'jsonld.NullRemoteDocument');
	}
	if(typeof remoteDoc.document === 'string') {
	remoteDoc.document = JSON.parse(remoteDoc.document);
	}
	} catch(ex) {
	return callback(new JsonLdError(
	'Could not retrieve a JSON-LD document from the URL. URL ' +
	'dereferencing not implemented.', 'jsonld.LoadDocumentError', {
	code: 'loading document failed',
	cause: ex,
	remoteDoc: remoteDoc
	}));
	}

jsonld.js/tests/test.js

Lines 671 to 676 in e63baf5

	try {
	doc.document = readJson(filename);
	} catch(ex) {
	throw {name: 'loading document failed'};
	}
	return doc;

That test provides content that cannot be parsed as JSON (regardless of the content type presented), so it fails to load -- which causes the test to pass.

[ariutta]

That makes sense. Thanks for the explanation.

I'm trying an experiment to see whether the library superagent-cache could be a solution for issue #127.

When there is no response, superagent returns an empty object as res.body instead of null, which caused the test to not pass. I was able to change that here so it now passes.

[dlongley]

@ariutta,

Ah, ok, makes sense.

[dlongley]

@ariutta,

There is also this: https://www.npmjs.com/package/cached-request

Which supposedly works with request -- which the node.js document loader is presently using.