fix oneof methods name (#3177)

When there is a oneof with at least two similar type, ie List<string> and List<int> this cause some conflict.

Author: MintsInc

.generator/src/generator/cli.py

@@ -68,6 +68,7 @@ def cli(specs, output):
     env.globals["get_default"] = openapi.get_default
     env.globals["get_container_type"] = openapi.get_container_type
     env.globals["get_security_names"] = openapi.get_security_names
+    env.globals["prepare_oneof_methods"] = formatter.prepare_oneof_methods
 
     api_j2 = env.get_template("Api.j2")
     model_j2 = env.get_template("model.j2")

.generator/src/generator/formatter.py

@@ -650,3 +650,76 @@ def get_response_type(schema, version):
 
 def attribute_path(attribute):
     return ".".join(attribute_name(a) for a in attribute.split("."))
+
+
+def prepare_oneof_methods(model, get_type_func):
+    """
+    Pre-compute method information for oneOf types to handle erasure collisions.
+
+    Returns a list of dicts with:
+    - schema: the original oneOf schema
+    - param_type: full parameterized type (e.g., "List<String>")
+    - unparam_type: unparameterized type (e.g., "List")
+    - use_factory: True if factory method needed (collision detected)
+    - constructor_name: name for constructor/factory method
+    - getter_name: name for getter method
+    """
+    # Handle both dict-style and object-style access
+    if isinstance(model, dict):
+        one_of = model.get('oneOf', [])
+    elif hasattr(model, 'oneOf'):
+        one_of = model.oneOf
+    elif hasattr(model, 'get'):
+        one_of = model.get('oneOf', [])
+    else:
+        return []
+
+    if not one_of:
+        return []
+
+    # First pass: count unparameterized types
+    unparam_counts = {}
+    for oneOf in one_of:
+        param_type = get_type_func(oneOf)
+        unparam_type = un_parameterize_type(param_type)
+        unparam_counts[unparam_type] = unparam_counts.get(unparam_type, 0) + 1
+
+    # Second pass: compute method names
+    result = []
+    for oneOf in one_of:
+        param_type = get_type_func(oneOf)
+        unparam_type = un_parameterize_type(param_type)
+        has_collision = unparam_counts[unparam_type] > 1
+
+        # Compute constructor/factory method name
+        if has_collision:
+            if param_type.startswith('List<'):
+                inner_type = param_type[5:-1]
+                constructor_name = f"from{inner_type}List"
+            else:
+                safe_type = param_type.replace('<', '').replace('>', '').replace(' ', '').replace(',', '')
+                constructor_name = f"from{safe_type}"
+        else:
+            constructor_name = None  # Regular constructor
+
+        # Compute getter method name
+        if has_collision:
+            if param_type.startswith('List<'):
+                inner_type = param_type[5:-1]
+                getter_name = f"get{inner_type}List"
+            else:
+                safe_type = param_type.replace('<', '').replace('>', '').replace(' ', '').replace(',', '')
+                getter_name = f"get{safe_type}"
+        else:
+            getter_name = f"get{unparam_type}"
+
+        result.append({
+            'schema': oneOf,
+            'param_type': param_type,
+            'unparam_type': unparam_type,
+            'use_factory': has_collision,
+            'constructor_name': constructor_name,
+            'getter_name': getter_name,
+        })
+
+    return result

.generator/src/generator/templates/modelOneOf.j2

@@ -139,11 +139,20 @@ public class {{ name }} extends AbstractOpenApiSchema {
         super("oneOf", Boolean.{{ "TRUE" if model.nullable else "FALSE" }});
     }
 
-    {%- for oneOf in model.oneOf %}
-    public {{ name }}({{ get_type(oneOf) }} o) {
+    {%- set oneof_methods = prepare_oneof_methods(model, get_type) %}
+    {%- for method_info in oneof_methods %}
+    {%- if method_info.use_factory %}
+    public static {{ name }} {{ method_info.constructor_name }}({{ method_info.param_type }} o) {
+        {{ name }} instance = new {{ name }}();
+        instance.setActualInstance(o);
+        return instance;
+    }
+    {%- else %}
+    public {{ name }}({{ method_info.param_type }} o) {
         super("oneOf", Boolean.{{ "TRUE" if model.nullable else "FALSE" }});
         setActualInstance(o);
     }
+    {%- endif %}
     {%- endfor  %}
 
     static {
@@ -204,19 +213,18 @@ public class {{ name }} extends AbstractOpenApiSchema {
         return super.getActualInstance();
     }
 
-    {%- for oneOf in model.oneOf %}
-    {%- set dataType = get_type(oneOf) %}
-    {%- set unParameterizedDataType = get_type(oneOf)|un_parameterize_type %}
+    {%- set oneof_methods = prepare_oneof_methods(model, get_type) %}
+    {%- for method_info in oneof_methods %}
 
     /**
-     * Get the actual instance of `{{ dataType|escape_html }}`. If the actual instance is not `{{ dataType|escape_html }}`,
+     * Get the actual instance of `{{ method_info.param_type|escape_html }}`. If the actual instance is not `{{ method_info.param_type|escape_html }}`,
      * the ClassCastException will be thrown.
      *
-     * @return The actual instance of `{{ dataType|escape_html }}`
-     * @throws ClassCastException if the instance is not `{{ dataType|escape_html }}`
+     * @return The actual instance of `{{ method_info.param_type|escape_html }}`
+     * @throws ClassCastException if the instance is not `{{ method_info.param_type|escape_html }}`
      */
-    public {{ dataType }} get{{ unParameterizedDataType }}() throws ClassCastException {
-        return ({{ dataType }})super.getActualInstance();
+    public {{ method_info.param_type }} {{ method_info.getter_name }}() throws ClassCastException {
+        return ({{ method_info.param_type }})super.getActualInstance();
     }
 
     {%- endfor %}