Invalid auto-complete when `const` is an object

[michaeltlombardi]

Describe the bug

When the value of const is an object, the auto-complete for the property/instance is garbled and invalid.

Instead of:

foo:
  bar: baz

It auto-completes as:

foo: 
  bar}: ${2:baz

Expected Behavior

Auto-complete for constant values should insert correctly, even when the constant is an object, as it does when the constant is an array, string, number, or null.

Current Behavior

Auto-complete inserts what appears to be a broken internal string.

Steps to Reproduce

1. Define a test schema as test.schema.json:

   {
       "$schema": "https://json-schema.org/draft/2020-12/schema",
       "title": "Schema with an object constant",
       "description": "Defines a schema with an object constant.",
       "type": "object",
       "properties": {
           "foo": {
               "title": "Property with an object constant",
               "const": {
                   "bar": "baz"
               }
           }
       }
   }
   

2. Define a test instance using that schema as test.instance.yaml:

   # yaml-language-server: $schema=test.schema.json
   

3. Type foo, wait for IntelliSense, then press enter.

4. Result:

   # yaml-language-server: $schema=test.schema.yaml
   foo: 
     bar}: ${2:baz
   

5. Define a test instance as test.schema.json

   {
       "$schema": "test.schema.json"
   }
   

6. Add a comma, then use IntelliSense to find the foo property and press enter to auto-complete.

7. Result:

      {
       "$schema": "test.schema.json",
       "foo": {
           "bar": "baz"
       }
   }
   

Environment

• [x] Windows
• [ ] Mac
• [ ] Linux
• [ ] other (please specify)