JSONata to flatten an object with two array values

Question

I am starting with an object having two values that are arrays. For each one I want to match all non-array values with the array values but with the index values in order e.g, index zero from each array, index 1 from each array, etc.:

The object:

{
  "taxedLineItems": [
    {
      "taxCodeNo": [
        "39050",
        "39051"
      ],
      "invoiceLink": "20265654",
      "lineItemNo": 99274137,
      "taxCode": [
        "VAT-A6",
        "Other"
      ]
    },
    {
      "taxCodeNo": [
        "39050",
        "39051"
      ],
      "invoiceLink": "20265654",
      "lineItemNo": 99274137,
      "taxCode": [
        "VAT-A6",
        "Other"
      ]
    },
    {
      "taxCodeNo": [
        "39050",
        "39051"
      ],
      "invoiceLink": "20265656",
      "lineItemNo": 99274142,
      "taxCode": [
        "VAT-A6",
        "Other"
      ]
    },
    {
      "taxCodeNo": [
        "39050",
        "39051"
      ],
      "invoiceLink": "20265656",
      "lineItemNo": 99274142,
      "taxCode": [
        "VAT-A6",
        "Other"
      ]
    }
  ]
}

I am wanting to "flatten" it so that all the combinations are expressed with no array values - desired output:

{
  "taxedLineItems": [
    {
      "taxCodeNo": "39050",
      "invoiceLink": "20265654",
      "lineItemNo": 99274137,
      "taxCode": "VAT-A6"
    },
    {
      "taxCodeNo": "39051",
      "invoiceLink": "20265654",
      "lineItemNo": 99274137,
      "taxCode": "Other"
    },
    {
      "taxCodeNo": "39050",
      "invoiceLink": "20265656",
      "lineItemNo": 99274142,
      "taxCode": "VAT-A6"
    },
    {
      "taxCodeNo": "39051",
      "invoiceLink": "20265656",
      "lineItemNo": 99274142,
      "taxCode": "Other"
    }
  ]
}

I have tried and failed with various $map attempts, etc. One failed attempt:

{
"taxedLineItemDetails":
$.taxedLineItems.$map(taxCode, function($v, $i, $a) {
    {
  "invoiceLink":$$.taxedLineItems[$i].invoiceLink,
  "lineItemNo":$$.taxedLineItems[$i].lineItemNo,
  "taxCode":$v  }
})
}

Some advice please!

Answer 1

The following is one option:

{
    "taxedLineItems":$reduce(
        $map($distinct(taxedLineItems.invoiceLink), function($link, $linkIndex) {
            $map($filter(taxedLineItems, function($v, $i) {$v.invoiceLink = $link}), function($item, $itemIndex) {
                {
                    "taxCodeNo": $item.taxCodeNo[$itemIndex],
                    "invoiceLink": $item.invoiceLink,
                    "lineItemNo": $item.lineItemNo,
                    "taxCode": $item.taxCode[$itemIndex]
                }
            })        
        }), $append)
}

With the following parts: This identifies the unique invoiceLinks:

$distinct(taxedLineItems.invoiceLink)

Mapping over those with:

$map($filter(taxedLineItems, function($v, $i) {$v.invoiceLink = $link})...

Will allow just dealing with the objects that relate to the invoiceLink.

Then the $itemIndex is relevant to the arrays for taxCodeNo and taxCode:

{
    "taxCodeNo": $item.taxCodeNo[$itemIndex],
    "invoiceLink": $item.invoiceLink,
    "lineItemNo": $item.lineItemNo,
    "taxCode": $item.taxCode[$itemIndex]
}

The wrapper of:

$reduce(..., $append)

Is per this link.

Working example:

(async function () {

  const transform = `{
      "taxedLineItems":$reduce(
          $map($distinct(taxedLineItems.invoiceLink), function($link, $linkIndex) {
              $map($filter(taxedLineItems, function($v, $i) {$v.invoiceLink = $link}), function($item, $itemIndex) {
                  {
                      "taxCodeNo": $item.taxCodeNo[$itemIndex],
                      "invoiceLink": $item.invoiceLink,
                      "lineItemNo": $item.lineItemNo,
                      "taxCode": $item.taxCode[$itemIndex]
                  }
              })        
          }), $append)
  }`;

  const result = await jsonata(transform).evaluate(obj);
  
  console.log(result);
  
})()

.as-console-wrapper { max-height: 100% !important; top: 0; }

<script src="https://cdn.jsdelivr.net/npm/jsonata/jsonata.min.js"></script>
<script>
const obj = {
  "taxedLineItems": [
    {
      "taxCodeNo": [
        "39050",
        "39051"
      ],
      "invoiceLink": "20265654",
      "lineItemNo": 99274137,
      "taxCode": [
        "VAT-A6",
        "Other"
      ]
    },
    {
      "taxCodeNo": [
        "39050",
        "39051"
      ],
      "invoiceLink": "20265654",
      "lineItemNo": 99274137,
      "taxCode": [
        "VAT-A6",
        "Other"
      ]
    },
    {
      "taxCodeNo": [
        "39050",
        "39051"
      ],
      "invoiceLink": "20265656",
      "lineItemNo": 99274142,
      "taxCode": [
        "VAT-A6",
        "Other"
      ]
    },
    {
      "taxCodeNo": [
        "39050",
        "39051"
      ],
      "invoiceLink": "20265656",
      "lineItemNo": 99274142,
      "taxCode": [
        "VAT-A6",
        "Other"
      ]
    }
  ]
}
</script>