Code generator produces invalid Python identifiers from generic type names with angle brackets

[bennerv]

Bug Description

When a Swagger/OpenAPI spec contains a $ref with angle brackets in the type name (e.g., Record<UserAssignedIdentityResourceId>), the code generator produces Python identifiers that contain < and > characters, which are invalid in Python. This causes a syntax error when the generated Azure CLI extension is loaded.

Error

cli.azure.cli.core: Unable to load extension 'aro-hcp: cannot assign to comparison (_create.py, line 403)'. Use --debug for more information.

Root Cause

In src/aaz_dev/swagger/model/schema/cmd_builder.py, the method _get_cls_definition_name() extracts the ref name (e.g., Record<UserAssignedIdentityResourceId>) and passes it through to_camel_case() without stripping angle brackets. This produces a cls name like Record<UserAssignedIdentityResourceId>_CreateOrUpdate_create, which then flows through to_snake_case() in the code generation templates to produce Python identifiers like:

_args_record<userassignedidentityresourceid>_create_or_update_create = None

Python interprets < and > as comparison operators, so this line becomes an attempt to assign to a comparison expression — a syntax error.

Affected Code Paths

The invalid identifier appears in multiple generated patterns:

• _args_record<...> (class attributes in arg group generators)
• _build_args_record<...> (method names in arg group generators)
• _schema_record<...> (class attributes in operation generators)
• _build_schema_record<...> (method names in operation generators)

Generated from:

• src/aaz_dev/cli/controller/az_arg_group_generator.py (lines 84, 168)
• src/aaz_dev/cli/controller/az_operation_generator.py (lines 599, 1021)

Reproduction

1. Use an API spec that contains a $ref to a type with angle brackets (e.g., #/definitions/Record<UserAssignedIdentityResourceId> from the Microsoft.RedHatOpenShift resource provider, API version 2025-12-23-preview)
2. Generate CLI commands using aaz-dev
3. Attempt to load the generated extension — it fails with the syntax error above

Suggested Fix

Strip angle brackets from ref names in _get_cls_definition_name() before converting to a cls name:

def _get_cls_definition_name(self, schema):
    assert isinstance(schema, ReferenceSchema)
    ref_name = schema.ref.split('/')[-1]
    ref_name = re.sub(r'[<>]', '', ref_name)
    schema_cls_name = f"{to_camel_case(ref_name.replace('.', ' '))}_{self.mutability}"
    ...

And as defense-in-depth, strip non-identifier characters in to_snake_case() in src/aaz_dev/utils/case.py:

def to_snake_case(name, separator='_'):
    assert isinstance(name, str)
    name = re.sub(r'[^a-zA-Z0-9_\-]', '', name)
    ...

Additional Note

The CMDClassField validation regex in src/aaz_dev/command/model/configuration/_fields.py uses re.match() which only checks from the start of the string, so Record<...> passes validation because Record matches [A-Z][a-zA-Z0-9_]+. This could be tightened to use a full-match anchor ($) to catch invalid names at validation time.

[bennerv]

here's a .patch file that appears to fix it.

diff --git a/src/aaz_dev/swagger/model/schema/cmd_builder.py b/src/aaz_dev/swagger/model/schema/cmd_builder.py
index 9e8e6ce9..eb9f6610 100644
--- a/src/aaz_dev/swagger/model/schema/cmd_builder.py
+++ b/src/aaz_dev/swagger/model/schema/cmd_builder.py
@@ -238,7 +238,11 @@ class CMDBuilder:
 
     def _get_cls_definition_name(self, schema):
         assert isinstance(schema, ReferenceSchema)
-        schema_cls_name = f"{to_camel_case(schema.ref.split('/')[-1].replace('.', ' '))}_{self.mutability}"
+        ref_name = schema.ref.split('/')[-1]
+        # Strip characters that are invalid in Python identifiers (e.g. angle brackets from
+        # generic type names like "Record<UserAssignedIdentityResourceId>")
+        ref_name = re.sub(r'[<>]', '', ref_name)
+        schema_cls_name = f"{to_camel_case(ref_name.replace('.', ' '))}_{self.mutability}"
         if self.mutability != MutabilityEnum.Read:
             if self.read_only:
                 schema_cls_name += "_read"
diff --git a/src/aaz_dev/utils/case.py b/src/aaz_dev/utils/case.py
index e58e010c..dceca47a 100644
--- a/src/aaz_dev/utils/case.py
+++ b/src/aaz_dev/utils/case.py
@@ -12,6 +12,8 @@ def to_camel_case(name, delimeters=""):
 
 def to_snake_case(name, separator='_'):
     assert isinstance(name, str)
+    # Strip angle brackets from generic type names (e.g. "Record<UserAssignedIdentityResourceId>")
+    name = re.sub(r'[<>]', '', name)
     name = re.sub('(.)([A-Z][a-z]+)', r'\1' + separator + r'\2', name)
     name = re.sub('([a-z0-9])([A-Z])', r'\1' + separator + r'\2', name).lower()
     return name.replace('-', separator).replace('_', separator)

[bennerv]

TSP file: https://github.com/Azure/azure-rest-api-specs-pr/blob/release-aro-hcp/2026-06-30-preview/specification/redhatopenshift/resource-manager/Microsoft.RedHatOpenShift/hcpopenshiftclusters/hcpCluster-models.tsp