[BugFix] Fix MammothModa2 Text-to-Image Bug (#4299)

Signed-off-by: menjiantong <menjiantong@foxmail.com>
Co-authored-by: menjiantong <menjiantong@foxmail.com>
Co-authored-by: Didan Deng <33117903+wtomin@users.noreply.github.com>

tests/unit/mammoth_moda2/test_mammoth_moda2_config.py

@@ -0,0 +1,91 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+"""
+Unit tests for MammothModa2 config classes.
+
+These tests verify the correct behavior of the Mammothmoda2Config class,
+particularly the get_text_config() method which is called during parent
+class initialization (PretrainedConfig.__init__ -> validation -> get_text_config).
+
+Regression test for: AttributeError: 'Mammothmoda2Config' object has no attribute 'llm_config'
+"""
+
+import pytest
+
+from vllm_omni.transformers_utils.configs.mammoth_moda2 import (
+    Mammothmoda2Config,
+    Mammothmoda2Qwen2_5_VLConfig,
+    Mammothmoda2Qwen2_5_VLTextConfig,
+)
+
+
+@pytest.mark.cpu
+class TestMammothmoda2Config:
+    """Tests for Mammothmoda2Config class."""
+
+    def test_get_text_config_returns_nested_text_config(self):
+        """
+        Verify that get_text_config() returns the nested text_config from llm_config.
+
+        This is a regression test for the AttributeError that occurred when
+        get_text_config() was called during parent class initialization before
+        llm_config was set.
+        """
+        config = Mammothmoda2Config(
+            llm_config={
+                "model_type": "mammothmoda2_qwen2_5_vl",
+            }
+        )
+
+        assert config.llm_config is not None
+        assert isinstance(config.llm_config, Mammothmoda2Qwen2_5_VLConfig)
+
+        text_config = config.get_text_config()
+        assert text_config is not None
+        assert isinstance(text_config, Mammothmoda2Qwen2_5_VLTextConfig)
+
+        # The text_config should be the same object as llm_config.text_config
+        assert text_config is config.llm_config.text_config
+
+    def test_get_text_config_returns_none_when_llm_config_is_none(self):
+        """Verify that get_text_config() returns None when llm_config is None."""
+        config = Mammothmoda2Config(llm_config=None)
+
+        assert config.llm_config is None
+        assert config.get_text_config() is None
+
+    def test_init_sets_llm_config_before_parent_init(self):
+        """
+        Verify that llm_config is set before parent __init__ is called.
+
+        This is critical because the parent PretrainedConfig.__init__ calls
+        validation which in turn calls get_text_config(). If llm_config is not
+        set before super().__init__(), an AttributeError will be raised.
+        """
+        # This should not raise an AttributeError
+        config = Mammothmoda2Config(
+            llm_config={
+                "model_type": "mammothmoda2_qwen2_5_vl",
+            }
+        )
+        assert config.llm_config is not None
+
+
+@pytest.mark.cpu
+class TestMammothmoda2Qwen2_5_VLConfig:
+    """Tests for Mammothmoda2Qwen2_5_VLConfig class."""
+
+    def test_has_text_config_attribute(self):
+        """Verify that Mammothmoda2Qwen2_5_VLConfig has text_config attribute."""
+        config = Mammothmoda2Qwen2_5_VLConfig()
+        assert hasattr(config, "text_config")
+        assert isinstance(config.text_config, Mammothmoda2Qwen2_5_VLTextConfig)
+
+    def test_text_config_has_expected_attributes(self):
+        """Verify that the nested text_config has expected attributes for token validation."""
+        config = Mammothmoda2Qwen2_5_VLConfig()
+        text_config = config.text_config
+
+        assert hasattr(text_config, "vocab_size")
+        assert hasattr(text_config, "image_token_id")
+        assert hasattr(text_config, "video_token_id")