mjhjmtu

I am trying to merge 4 JSON files (in the future maybe two more).
The only common factor between the newline delimited JSON files is "vulnid".

File 1: 
"vulnid":"cve1", "product":"product1"
"vulnid":"cve2", "product":"product2"
"vulnid":"cve3", "product":"product3"
"vulnid":"cve4", "product":""
"vulnid":"cve5", "product":""
"vulnid":"cve6", "product":""

File 2: 
"vulnid":"cve1", "version":"version1"
"vulnid":"cve2", "version":"version2"
"vulnid":"cve3", "version":"version3"
"vulnid":"cve4", "version":"version4"

File 3: 
"vulnid":"cve1", "patch":"patch1"
"vulnid":"cve2", "patch":"patch2"
"vulnid":"cve3", "patch":"patch3"
"vulnid":"cve4", "patch":""

File 4: 
"vulnid":"cve1", "speed":"speed1"
"vulnid":"cve2", "power":"power2"
"vulnid":"cve3", "amps":"amps3"
"vulnid":"cve4", "product":"product4"
"vulnid":"cve4", "patch":"patch4"


Required output:
"vulnid":"cve1", "product":"product1", "version":"version1", "patch":"patch1", "speed":"speed1"
"vulnid":"cve2", "product":"product2", "version":"version2", "patch":"patch2", "power":"power2"
"vulnid":"cve3", "product":"product3", "version":"version3", "patch":"patch3", "amps":"amps3"
"vulnid":"cve4", "product":"product4", "version":"version4", "patch":"patch4"
"vulnid":"cve5", "product":""
"vulnid":"cve6", "product":""

What I have tried so far:

jq -s '.[0] * .[1] * .[3] * .[4]' json1 json2 json3 json4
jq -s '.[0] + .[1] + .[3] + .[4]' json1 json2 json3 json4

... and multiple different combinations of jq, all of them provided incorrect results and proved the point that I am not understand the tool.

Is this even possible to accomplish such merging using the field "vulnid" with jq?

The shortest jq solution:

jq -sc 'group_by(.vulnid) | add' file*.json

The output:

"vulnid":"cve1","product":"product1","version":"version1","patch":"patch1","speed":"speed1"
"vulnid":"cve2","product":"product2","version":"version2","patch":"patch2","power":"power2"
"vulnid":"cve3","product":"product3","version":"version3","patch":"patch3","amps":"amps3"
"vulnid":"cve4","product":"product4","version":"version4","patch":"patch4"
"vulnid":"cve5","product":""
"vulnid":"cve6","product":""

Yeah, I think so.

If we change the data so that we have the vulnid strings as keys, with the object itself as the corresponding value (e.g. "cve1": "vulnid": "cve1", "product": "product1" ), then we can use reduce and * to combine the ones with the same keys. The first map() below produces the correct format for the reduce.

So, with your sample input in the file json:

$ < json jq -s 'map((.vulnid): . ) | reduce . as $item (; . * $item) '
{
 "cve1": 
 "vulnid": "cve1",
 "product": "product1",
 "version": "version1",
 "patch": "patch1",
 "speed": "speed1"
 ,
 ...

Then it's rather simple to drop the fluff around the objects to get the expected output:

$ < json jq -s 'map((.vulnid): . ) | 
 reduce . as $item (; . * $item) | map(.) | .'

 "vulnid": "cve1",
 "product": "product1",
 "version": "version1",
 "patch": "patch1",
 "speed": "speed1"

...

I wouldn't be surprised if there was a better way to do all of this, though.