Why does .location return a differently formatted value?

[Kerryliu]

For context, the problem I'm trying to solve.
Azure Front Door Private Link is only supported in certain regions. My Azure Functions do not have a 1:1 mapping with these supported regions, so I need to manually map these regions.

E.g.:

var locationToPrivateLinkRegion = {
  'westus': 'westus3'
  'westus2': 'westus3'
  'westus3': 'westus3'  // Even if there is a 1:1 mapping, include it here to keep the pattern consistent.
}

Later I would use it as such:

privateLinkLocation: locationToPrivateLinkRegion[myFunctionApp.location]

However, what I found out is that myFunctionApp.location does not return westus, westus2, westus3, etc, as expected. Instead what i get back is West US, West US 2, West US 3.

So now my map needs to look like:

var locationToPrivateLinkRegion = {
  'West US': 'westus3'
  'West US 2': 'westus3'
  'West US 3': 'westus3'
}

If a resource is created with something like location: westus. Why does it poop out a differently formatted value (West US) when I call .location? This behavior seems very questionable to me. Is there a different method/field/function I should be using?

[GABRIELNGBTUC]

It's likely that it is a provider bug since most other providers return the real name of the region instead of the display name.

The only solution for this is to open a support ticket and hope their team takes the feedback.

[slavizh]

You can always do toLower(replace(myFunctionApp.location, ' ', '')) to format location to its value even if it is returned in display name value.

[anthony-c-martin]

This is the most practical way to handle this. Azure Resource Manager's built-in location string comparison logic is implemented very similarly - it performs a case-insensitive comparison of alphanumeric characters to determine equality. In practice, the only non-alphanumeric characters that are used in location strings are spaces.

Here's an approximation in C# of what ARM's location comparison logic looks like:

public static bool AreLocationsEqual(string first, string second)
    => Enumerable.SequenceEqual(
        first.ToLowerInvariant().Where(char.IsLetterOrDigit),
        second.ToLowerInvariant().Where(char.IsLetterOrDigit));

So technically, all of the following strings would be considered "equal" by ARM:

• "WestUS3"
• "West US 3"
• "westus3"
• "west-us-3"
• "west US 3"