Unexpected tailing comma

[g-chao]

Suppose we have the following JS code

const jju = require('jju');
const rawJsonString = `{
  "entry1": [
    {
      "path1": "path1"
    }
  ],
  "entry2": "value2"
}
`
const jsonObject = jju.parse(rawJsonString);

// add new entries to object
jsonObject["entry3"] = {
  "value2": {
    "2": true
  },
  "value3": {
    "3": true
  }
}

// call the update API
const newRawJsonString = jju.update(rawJsonString, jsonObject);

// print out to check the value
console.log(newRawJsonString);

Execute it, it will see following output

{
  "entry1": [
    {
      "path1": "path1"
    }
  ],
  "entry2": "value2",
  "entry3": {
    "value2": {
      "2": true
    },
    "value3": {
      "3": true
    }
  }
}

Which is correct.

Now, let's change the rawJsonString in the code, the only difference, is now the entry1 has two elements

const jju = require('jju');
const rawJsonString = `{
  "entry1": [
    {
      "path1": "path1"
    },
    {
      "path2": "path2"
    }
  ],
  "entry2": "value2"
}
`
const jsonObject = jju.parse(rawJsonString);

// add new entries to object
jsonObject["entry3"] = {
  "value2": {
    "2": true
  },
  "value3": {
    "3": true
  }
}

// call the update API
const newRawJsonString = jju.update(rawJsonString, jsonObject);

// print out to check the value
console.log(newRawJsonString);

Execute it, it will see following output

{
  "entry1": [
    {
      "path1": "path1"
    },
    {
      "path2": "path2"
    }
  ],
  "entry2": "value2",
  "entry3": {
    "value2": {
      "2": true, // <--- this tailing comma should not be here
    },
    "value3": {
      "3": true, // <--- this tailing comma should not be here
    }, // <--- this tailing comma should not be here
  }
}

Which is not correct, you can see there are unexpected tailing commas on the new added entries.