User defined type causes invalid resources loop generation

[yfakariya]

Bicep version

0.28.1

Describe the bug

Loop for user defined array should be treated as built-in array.
That is, following two bicep sources should be built as same:

param p arrray
resource r 'Microsoft.Storage/storageAccounts@2023-05-01' = [
  for item in p : {
    name: item.name
  }
]

and

param p object[]
resource r 'Microsoft.Storage/storageAccounts@2023-05-01' = [
  for item in p : {
    name: item.name
  }
]

should be built as identically except parameter type declaration.
However, 2nd source is built as invalid ARM template as following:

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "languageVersion": "2.0",
  "contentVersion": "1.0.0.0",
  "metadata": {...},
  "parameters": {
    "p": {
      "type": "array",
      "items": {
        "type": "object"
      }
    }
  },
  "resources": {
    "r": {
      "copy": {
        "name": "r",
        "count": "[length(parameters('p'))]"
      },
      "type": "Microsoft.Storage/storageAccounts",
      "apiVersion": "2023-05-01",
      "name": "[parameters('p')[copyIndex()].name]"
    }
  }
}

The resources must be array with objects as following:

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "metadata": {...},
  "parameters": {
    "p": {
      "type": "array"
    }
  },
  "resources": [
    {
      "copy": {
        "name": "r",
        "count": "[length(parameters('p'))]"
      },
      "type": "Microsoft.Storage/storageAccounts",
      "apiVersion": "2023-05-01",
      "name": "[parameters('p')[copyIndex()].name]"
    }
  ]
}

More strangely, just declaring user defined array type causes such breaking for resources:

param p array
type objArray = object[]
resource r 'Microsoft.Storage/storageAccounts@2023-05-01' = [
  for item in p : {
    name: item.name
  }
]

It is built as:

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "languageVersion": "2.0",
  "contentVersion": "1.0.0.0",
  "metadata": {...},
  "definitions": {
    "objArray": {
      "type": "array",
      "items": {
        "type": "object"
      }
    }
  },
  "parameters": {
    "p": {
      "type": "array"
    }
  },
  "resources": {
    "r": {
      "copy": {
        "name": "r",
        "count": "[length(parameters('p'))]"
      },
      "type": "Microsoft.Storage/storageAccounts",
      "apiVersion": "2023-05-01",
      "name": "[parameters('p')[copyIndex()].name]"
    }
  }
}

It looks that declaration of user defined array causes this bug.

To Reproduce

Run az bicep build for above example, then check result json.

Additional context

(none)

[jeskew]

Hi @yfakariya,

The example with a user-defined type is built as a "symbolic name" template, which requires that the value of the resources property be an object rather than an array. User-defined types in ARM require the use of language version 2.0, which in turn requires the "symbolic name" (object-based) syntax for resources.

Did you encounter any errors deploying the template compiled with user-defined types? I don't see any errors in the built ARM artifacts, but I may be missing something.

[yfakariya]

@jeskew

Thank you for quick and detailed response. As you say, I missed out languageVersion and symbllic name. It was absolutely my misunderstanding. Sorry for noise.