Jolt spec to handle the JSON when the nested array is present and when it is not present

Question

Dynamic Jolt spec to handle when one nested array is present and and if nested array is not present

My jolt spec is working perfectly fine if we receive the nested array, but if they send a JSON without the nested array, its failing. Is there a way to make it work for both cases

Input 1 :

[
  {
    "payload": {
      "header": {
        "sender": "GRPSPM"
      },
      "article": {
        "groupModelNumber": "LPZ48",
        "groupArticleNumber": "IF5561",
        "rmh": [
          {
            "rmhMarketingDivision": "1",
            "rmhProductDivision": "1",
            "rmhGender": "2",
            "rmhCategory": "20",
            "rmhProductType": "09",
            "retailDepartment": "11",
            "retailSubDepartment": "112",
            "retailClass": "11220",
            "retailSubClass": "1122009"
          }
        ],
        "sku": [
          {
            "skuChange": false,
            "sourcingSizeScale": "T1",
            "sourcingSizeCode2": "28",
            "sourcingSizeCode3": "610",
            "eanNumber": "4066765529183",
            "upcNumber": "196472210778",
            "feasibilityIndicator": true,
            "activeIndicator": true
          },
          {
            "skuChange": false,
            "sourcingSizeScale": "T1",
            "sourcingSizeCode2": "31",
            "sourcingSizeCode3": "640",
            "eanNumber": "4066765529169",
            "upcNumber": "196472210761",
            "feasibilityIndicator": true,
            "activeIndicator": true
          }
        ]
      }
    }
  }
]

Input 2 :

[
  {
    "payload": {
      "header": {
        "sender": "GRPSPM"
      },
      "article": {
        "groupModelNumber": "LPZ48",
        "groupArticleNumber": "IF5561",
        "rmh": [
          {
            "rmhMarketingDivision": "1",
            "rmhProductDivision": "1",
            "rmhGender": "2",
            "rmhCategory": "20",
            "rmhProductType": "09",
            "retailDepartment": "11",
            "retailSubDepartment": "112",
            "retailClass": "11220",
            "retailSubClass": "1122009"
          }
        ]
      }
    }
  }
]

Jolt Spec which i am currently using

[
  {
    "operation": "shift",
    "spec": {
      "@": "input",
      "@(0)": "val0"
    }
  },
  {
    "operation": "modify-overwrite-beta",
    "spec": {
      "val0": "=toString",
      "chr": ["=substring(@(1,val0),0,1)", "["]
    }
  },
  {
    "operation": "shift",
    "spec": {
      "chr": {
        "{": {
          "@(2,input)": "[]"
        },
        "*": {
          "@(2,input)": ""
        }
      }
    }
  },
  {
    "operation": "shift",
    "spec": {
      "*": {
        "payload": {
          "article": {
            "groupModelNumber": "groupModelNumber",
            "groupArticleNumber": "groupArticleNumber",
            "sku": {
              "*": {
                "sourcingSizeCode3": "sourcingSizeCode3",
                "feasibilityIndicator": "feasibilityIndicator",
                "activeIndicator": "activeIndicator"
              }
            },
            "rmh": {
              "*": {
                "retailClass": "retailClass",
                "retailSubClass": "retailSubClass",
                "retailDepartment": "retailDepartment",
                "retailSubDepartment": "retailSubDepartment",
                "rmhProductDivision": "rmhProductDivision",
                "rmhCategory": "rmhCategory",
                "rmhProductType": "rmhProductType"
              }
            }
          }
        }
      }
    }
  }, 
  {
    "operation": "shift",
    "spec": {
      "sourcingSizeCode3": {
        "*": {
          "@(2,groupModelNumber)": "[#2].groupModelNumber",
          "@": "[#2].&2",
          "@(2,retailClass)": "[#2].retailClass",
          "@(2,retailSubClass)": "[#2].retailSubClass",
          "@(2,retailDepartment)": "[#2].retailDepartment",
          "@(2,retailSubDepartment)": "[#2].retailSubDepartment",
          "@(2,rmhProductDivision)": "[#2].rmhProductDivision",
          "@(2,rmhCategory)": "[#2].rmhCategory",
          "@(2,rmhProductType)": "[#2].rmhProductType"
        }
      },
      "activeIndicator": {
        "*": {
          "@": "[#2].&2"
        }
      },
      "feasibilityIndicator": {
        "*": {
          "@": "[#2].&2"
        }
      }
    }
  }
]

Output Expected for Input 1 :

[
  {
    "groupModelNumber": "LPZ48",
    "sourcingSizeCode3": "610",
    "retailClass": "11220",
    "retailSubClass": "1122009",
    "retailDepartment": "11",
    "retailSubDepartment": "112",
    "rmhProductDivision": "1",
    "rmhCategory": "20",
    "rmhProductType": "09",
    "activeIndicator": true,
    "feasibilityIndicator": true
  },
  {
    "groupModelNumber": "LPZ48",
    "sourcingSizeCode3": "640",
    "retailClass": "11220",
    "retailSubClass": "1122009",
    "retailDepartment": "11",
    "retailSubDepartment": "112",
    "rmhProductDivision": "1",
    "rmhCategory": "20",
    "rmhProductType": "09",
    "activeIndicator": true,
    "feasibilityIndicator": true
  }
]

Output Expected for Input 2 :

{
  "groupModelNumber" : "LPZ48",
  "groupArticleNumber" : "IF5561",
  "retailClass" : "11220",
  "retailSubClass" : "1122009",
  "retailDepartment" : "11",
  "retailSubDepartment" : "112",
  "rmhProductDivision" : "1",
  "rmhCategory" : "20",
  "rmhProductType" : "09"
}

Answer 1

You can combine the cases while shortening the whole transformation as

[
  {
    "operation": "shift",
    "spec": {
      "*": {
        "payload": {
          "article": {
            "sku|rmh": {
              "*": {
                "@(2,groupModelNumber)": "[#2].groupModelNumber",
                "@(2,groupArticleNumber)": "[#2].groupArticleNumber",
                "sourcingSizeCode3|feasibilityIndicator|activeIndicator": "[#2].&",
                "@(2,rmh[0].retailClass)": "[#2].retailClass",
                "@(2,rmh[0].retailSubClass)": "[#2].retailSubClass",
                "@(2,rmh[0].retailDepartment)": "[#2].retailDepartment",
                "@(2,rmh[0].retailSubDepartment)": "[#2].retailSubDepartment",
                "@(2,rmh[0].rmhProductDivision)": "[#2].rmhProductDivision",
                "@(2,rmh[0].rmhCategory)": "[#2].rmhCategory",
                "@(2,rmh[0].rmhProductType)": "[#2].rmhProductType"
              }
            }
          }
        }
      }
    }
  },
  { // only pick one component from the repeating components for the innermost arrays (if they're array) 
    "operation": "cardinality",
    "spec": {
      "*": {
        "*": "ONE"
      }
    }
  },
  { // remove array wrapper if the current array contains single object 
    "operation": "shift",
    "spec": {
      "*": {
        "@": ""
      }
    }
  }
]