Fix: binary data representation when sending data through HTTP & MQTT #690

[MayankSingh-NEC]

Hi @mapedraza and @fgalan,

This PR originates from #696
Issue: #690

[MayankSingh-NEC]

Hi @mapedraza and @fgalan ,

I have performed the UTs on my local environment and all the test cases are getting passed.
Please find the below attachment:

MQTT: Commands
When a command with payloadtype arrives to the Agent for a device with the MQTT_JSON protocol
✓ should return a 204 OK without errors
✓ should update the status in the Context Broker
✓ binaryfromhex - should publish the transformed command information in the MQTT topic (146ms)
✓ text - should publish the transformed command information in the MQTT topic (140ms)

The above UT (CI / Unit Tests (14.x)) is not failed due to this PR. Please let me know your opinion. Thanks!

[mapedraza]

Suggested change

	mqttClient.publish('/1234/MQTT_2/attrs/humidity', '0x4D', null, function (error) {
	mqttClient.publish('/1234/MQTT_2/attrs/humidity', '0x4D', null, function (error) {

This case is not totally correct. You are not sending binary data through MQTT here. When sending '0x4D', you are sending a string of ascii chars. In that case, the binary representation (in Hex) is made of 4 bytes:

Hex representation

0x30,0x78,0x34,0x44

Binary representation

00110000 01111000 00110100 01000100

So, the expected value persisted in that case should be:

"value": "30783444"

So, the initial part (0x), should not be removed

In order to don't lead to confusion, I suggest to change the test string without including the initial part 0x.
Additionally, the part of the code that removes 0x should be removed

[mapedraza]

Overpassed by #736