jq to merge two files with different formats

November 2, 2022

I have two files

file 1

{
    "version": "2",
    "run_id": "1",
    "crn": "crn",
    "date": "2022-11-02T02:09:30.629Z",
    "evidences": [
        {
            "version": "2",
            "id": "2d"
        },
        {
            "version": "2",
            "id": "3e"
        }  
]

file 2

[
        {
            "version": "3",
            "id": "3d"
        },
        {
            "version": "2",
            "id": "3f"
        }    
]

can we use jq to merge contents from file 2 into evidences section of file 1? which the result should like below

file 1

{
    "version": "2",
    "run_id": "1",
    "crn": "crn",
    "date": "2022-11-02T02:09:30.629Z",
    "evidences": [
        {
            "version": "2",
            "id": "2d"
        },
        {
            "version": "2",
            "id": "3e"
        },
        {
            "version": "3",
            "id": "3d"
        },
        {
            "version": "2",
            "id": "3f"
        }    
]

>Solution :

All you need is += to add up arrays while retaining the context, and input to access the second file:

jq '.evidences += input' file1.json file2.json

{
  "version": "2",
  "run_id": "1",
  "crn": "crn",
  "date": "2022-11-02T02:09:30.629Z",
  "evidences": [
    {
      "version": "2",
      "id": "2d"
    },
    {
      "version": "2",
      "id": "3e"
    },
    {
      "version": "3",
      "id": "3d"
    },
    {
      "version": "2",
      "id": "3f"
    }
  ]
}

Demo