How to have JSON subquery return empty array rather than null when there are no rows

I have a (hypothetical) JSON schema that calls for a document to look like:

[
  {
    "tableName": "Embeddings",
    "object_id": 1301579675,
    "type_desc": "USER_TABLE",
    "create_date": "2023-05-03T19:41:56.940",
    "indexes": [
      {
        "name": "PK_Embeddings",
        "type_desc": "CLUSTERED",
        "is_unique": true,
        "is_primary_key": true
      },
      {
        "name": "IX_Embeddings_DimValue",
        "type_desc": "NONCLUSTERED",
        "is_unique": false,
        "is_primary_key": false
      }
    ]
  }
]

Which you can generate using the query:

SELECT 
    t.Name,
    t.object_id,
    t.type_desc,
    t.create_date,
    (
        SELECT name, type_desc, is_unique, is_primary_key
        FROM sys.indexes si
        WHERE si.object_id = t.object_id
        AND type <> 0
        FOR JSON PATH) indexes
FROM sys.tables t
FOR JSON PATH

You’ll notice the indexes array.

• if there are indexes, they appear in the array.
• If there are no indexes, i want the array to be empty.

But unfortunately in reality, if the list of indexes is empty the indexes array won’t be empty, but instead be omitted:

  {
    "Name": "DateTests",
    "object_id": 901578250,
    "type_desc": "USER_TABLE",
    "create_date": "2020-01-20T10:56:27.757"
  }

when it should return:

  {
    "Name": "DateTests",
    "object_id": 901578250,
    "type_desc": "USER_TABLE",
    "create_date": "2020-01-20T10:56:27.757",
    "indexes": []
  }

How can I instruct SQL Server to return an empty of array of results, rather than no array of results, if there are no results, when running a query FOR JSON?

Bonus Chatter

It’s odd that it returns nothing, rather than an "empty array", because SQL loves to return an empty set of something:

SELECT name, type_desc, is_unique, is_primary_key FROM sys.indexes WHERE 0=1

name	type_desc	is_unique	is_primary_key

0 row(s) affected

It doesn’t return nothing, it returns an empty something.

So how can I make JSON return an empty something?