Yet another array merging issue: root node array

[noraj]

I'm seen most of the issues are related to merging arrays but yet I didn't find the solution reading them.

The issue: root node array

root node array is not merging properly like is does when it's a sub-node array

file1.json

[
  {"title": "A"},
  {"title": "B"}
]

file2.json

[
  {"title": "C"},
  {"title": "D"}
]

expected result

[
  {"title": "A"},
  {"title": "B"},
  {"title": "C"},
  {"title": "D"}
]

with the 4 possible combinations of concatArrays, + mergeArrays

concatArrays	mergeArrays	output
true	true	❌
true	false	❌
false	true	❌
false	false	❌

{
  "0": {
    "title": "C"
  },
  "1": {
    "title": "D"
  }
}

Similar but not exactly the same issues

• Still problem with array merging #19, mergeArrays: false #22, Merging multiple files keeps only keys from last file in array #18, Cant merge an json Array #11 the array there is an element not the root node

Working example of sub-node array

file1.json

{
  "array": [
    {"title": "A"},
    {"title": "B"}
  ]
}

file2.json

{
  "array": [
    {"title": "C"},
    {"title": "D"}
  ]
}

concatArrays: true + mergeArrays: true

{
  "array": [
    {
      "title": "A"
    },
    {
      "title": "B"
    },
    {
      "title": "C"
    },
    {
      "title": "D"
    }
  ]
}

[joshswan]

You need to override the startObj for root level arrays or it attempts to merge those arrays into the default starting object: {}. There's a test case that covers this scenario and looks like:

gulp.src(['test/json/array1.json', 'test/json/array2.json']).pipe(merge({
  startObj: [],
}));

Let me know if you have further issues and happy to accept a PR for improving the docs if needed :)

[noraj]

@joshswan Thanks.