Remove legacy NGSIv1 code - discover function

[mapedraza]

Some legacy NGSIv1 requests remain in the codebase after merging #253

This function returns the registrations for a given entity.

lightweightm2m-iotagent/lib/ngsiUtils.js

Lines 128 to 149 in c072213

	function discoverContextAvailability(host, port, service, subservice, id, type, attributes, callback) {
	const options = {
	url: 'http://' + host + ':' + port + '/v1/registry/discoverContextAvailability ',
	method: 'POST',
	headers: {
	'fiware-service': service,
	'fiware-servicepath': subservice
	},
	json: {
	entities: [
	{
	type,
	id,
	isPattern: 'false'
	}
	],
	attributes
	}
	};
	request(options, callback);
	}

Having in mind the NGSIv2 spec does not allow to query for a specific entity, there is not a direct equivalent. But this function is only used at test/unit/ngsiv2/registration-test.js

lightweightm2m-iotagent/test/unit/ngsiv2/registration-test.js

Line 98 in c072213

ngsiClient.discover('TestClient:Light', 'Light', undefined, function(error, response, body) {

Since the purpose of the function is just to check if the registration was created properly (and used just for testing), making the request GET v2/registrations in this case have the same effect (since the DB is cleaned between tests)

It was discovered here

[jason-fox]

lib/ngsiUtils.js should be deleted - it really doesn't deserve to exist within the IoT Agent itself. If it is just a test expectation, the code should be moved to the test itself, if this a common NGSI need then it should be pushed into the iotagent-node-lib.

IoT Agents should never make direct NGSI requests, that is the job of iotagent-node-lib.

[fgalan]

lib/ngsiUtils.js should be deleted - it really doesn't deserve to exist within the IoT Agent itself. If it is just a test expectation, the code should be moved to the test itself, if this a common NGSI need then it should be pushed into the iotagent-node-lib.

IoT Agents should never make direct NGSI requests, that is the job of iotagent-node-lib.

Is lightweightm2m-iotagent the only one in this situation? Is there a lib/ngsiUtils.js file in other agents (UL, JSON, etc.)?

[jason-fox]

It is the only one of the Telefónica IoT Agents with lib/ngsiUtils.js - I guess it is one of the oldest codebases

[mapedraza]

This IoTA or, at least, these tests, are a bit different compared with the other IoTAS. In the other IoTAS, the tests are executed without the need of having a CB running, verifying the requests that the IoTA makes with the mock server. In this case the agent is connected to a real CB, and what is checked is that the action has had an effect on the CB itself.

Moving ngsiUtils.jsto test/ folder would make more sense since the usage of those function are exclusively for testing purposes as helpers.

[fgalan]

PR #257

[fgalan]

After merging PR #257, this issue can be now closed. Some bits moved to #235 (comment)