Fix VMSizes-Must-Match-Template to support nested output properties

[Copilot]

The VMSizes-Must-Match-Template test only checked first-level output properties, causing false negatives when VM SizeSelector references were nested 2+ levels deep.

Problem

When outputs were structured with nested objects:

"outputs": {
  "clusters": {
    "slurm": {
      "schedulerNode": {
        "sku": "[steps('scheduler').schedulerSection.vmsize]"
      }
    }
  }
}

The test would fail with "Could not find VM SizeSelector 'vmsize' in outputs" because it only iterated top-level properties where $out.Value is an object, not a string.

Changes

• Added Find-OutputProperty helper function: Recursively traverses nested objects to locate VM SizeSelector patterns at any depth while preserving the top-level property name for template parameter matching
• Updated search logic: Replaced flat property iteration with recursive search call
• Added test coverage: 2-level, 3-level, and multi-selector nested output scenarios

The recursive function checks if a value is a string matching the pattern, or an object requiring further traversal. It returns the top-level property name (e.g., "clusters") needed for $MainTemplateParameters lookup, not the full nested path.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• aka.ms
  • Triggering command: /usr/bin/pwsh pwsh -Command Import-Module ./arm-ttk/arm-ttk.psd1 -Force; Test-AzTemplate -TemplatePath './unit-tests/VMSizes-Must-Match-Template/Pass/Nested-Outputs-2-Levels' -Test 'VMSizes-Must-Match-Template' (dns block)
  • Triggering command: /usr/bin/pwsh pwsh -Command Import-Module ./arm-ttk/arm-ttk.psd1 -Force; Test-AzTemplate -TemplatePath './unit-tests/VMSizes-Must-Match-Template/Pass/Nested-Outputs-3-Levels' -Test 'VMSizes-Must-Match-Template' (dns block)
  • Triggering command: /usr/bin/pwsh pwsh -Command Import-Module ./arm-ttk/arm-ttk.psd1 -Force; Test-AzTemplate -TemplatePath './unit-tests/VMSizes-Must-Match-Template/Pass/Element-Nested-In-Section' -Test 'VMSizes-Must-Match-Template' (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

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This section details on the original issue you should resolve

<issue_title>Can't use VM SizeSelector in nested outputs</issue_title>
<issue_description>Hello,

I have the following output object in my uidefinition.json file:

"clusters": {
        "slurm": {
          "startCluster": "[steps('scheduler').clusterSettings.startCluster]",
          "version": "[steps('scheduler').schedulerSection.slurmVersion]",
          "healthCheckEnabled": "[steps('scheduler').clusterSettings.healthCheck]",
          "schedulerNode": {
            "sku": "[steps('scheduler').schedulerSection.vmsize]",
            "osImage": "[if(equals(steps('scheduler').schedulerSection.ImageName,'custom'),steps('scheduler').schedulerSection.customImageName,steps('scheduler').schedulerSection.ImageName)]"
          },
          "loginNodes": {
            "sku": "[steps('scheduler').loginNodesSection.vmsize]",
            "osImage": "[if(not(steps('scheduler').schedulerSection.universalImage),if(equals(steps('scheduler').loginNodesSection.ImageName,'custom'),steps('scheduler').loginNodesSection.customImageName,steps('scheduler').loginNodesSection.ImageName),if(equals(steps('scheduler').schedulerSection.ImageName,'custom'),steps('scheduler').schedulerSection.customImageName,steps('scheduler').schedulerSection.ImageName))]",
            "initialNodes": "[int(steps('scheduler').loginNodesSection.initialNodes)]",
            "maxNodes": "[int(steps('scheduler').loginNodesSection.maxNodes)]"
          },
          "htc": {
            "sku": "[steps('slurmSettings').HTCSection.vmsize]",
            "maxNodes": "[int(steps('slurmSettings').HTCSection.maxNodes)]",
            "osImage": "[if(not(steps('scheduler').schedulerSection.universalImage),if(equals(steps('slurmSettings').HTCSection.ImageName,'custom'),steps('slurmSettings').HTCSection.customImageName,steps('slurmSettings').HTCSection.ImageName),if(equals(steps('scheduler').schedulerSection.ImageName,'custom'),steps('scheduler').schedulerSection.customImageName,steps('scheduler').schedulerSection.ImageName))]",
            "useSpot": "[steps('slurmSettings').HTCSection.spotHTC]"
          },
          "hpc": {
            "sku": "[steps('slurmSettings').HPCSection.vmsize]",
            "maxNodes": "[int(steps('slurmSettings').HPCSection.maxNodes)]",
            "osImage": "[if(not(steps('scheduler').schedulerSection.universalImage),if(equals(steps('slurmSettings').HPCSection.ImageName,'custom'),steps('slurmSettings').HPCSection.customImageName,steps('slurmSettings').HPCSection.ImageName),if(equals(steps('scheduler').schedulerSection.ImageName,'custom'),steps('scheduler').schedulerSection.customImageName,steps('scheduler').schedulerSection.ImageName))]"
          },
          "gpu": {
            "sku": "[steps('slurmSettings').GPUSection.vmsize]",
            "maxNodes": "[int(steps('slurmSettings').GPUSection.maxNodes)]",
            "osImage": "[if(not(steps('scheduler').schedulerSection.universalImage),if(equals(steps('slurmSettings').GPUSection.ImageName,'custom'),steps('slurmSettings').GPUSection.customImageName,steps('slurmSettings').GPUSection.ImageName),if(equals(steps('scheduler').schedulerSection.ImageName,'custom'),steps('scheduler').schedulerSection.customImageName,steps('scheduler').schedulerSection.ImageName))]"
          }
        },
        "ood": {
          "type": "[if(steps('ood').OODSection.deployOOD,'enabled','disabled')]",
          "startCluster": "[if(steps('ood').OODSection.deployOOD,steps('ood').OODSection.startCluster,basics('nullValue'))]",
          "sku": "[if(steps('ood').OODSection.deployOOD,steps('ood').OODSection.vmsize,basics('nullValue'))]",
          "osImage": "[if(steps('ood').OODSection.deployOOD,if(equals(steps('ood').OODSection.ImageName,'custom'),steps('ood').OODSection.customImageName,steps('ood').OODSection.ImageName),basics('nullValue'))]",
          "userDomain": "[if(steps('ood').OODSection.deployOOD,steps('ood').OODSection.userDomain,basics('nullValue'))]",
          "fqdn": "[if(not(equals(steps('ood').OODSection.fqdn,'')),steps('ood').OODSection.fqdn,basics('nullValue'))]",
          "registerEntraIDApp": "[if(steps('ood').OODSection.deployOOD,equals(steps('ood').OODSection.registerEntraIDApp,'autoregister'),basics('nullValue'))]",
          "appId": "[if(equals(steps('ood').OODSection.registerEntraIDApp,'existing'),steps('ood').OODSection.clientId,basics('nullValue'))]",
          "appManagedIdentityId": "[if(equals(steps('ood').OODSection.registerEntraIDApp,'existing'),steps('ood').OODSection.managedIdentity.id,basics('nullValue'))]"
        }
      }

This fails validation because ARM-ttk doesn't recognize that the VM SizeSelector elements are present in the outputs when they're multiple levels deep into an object. Here's the result from using the above in a UI definition JSON:

Validation passes, however, when one level ...

• Fixes Can't use VM SizeSelector in nested outputs #786

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