test(dashscope): cover thinking mode null guards

Author: guslegend

agentscope-core/src/test/java/io/agentscope/core/model/DashScopeChatModelTest.java

@@ -705,6 +705,35 @@ void testApplyThinkingModeDegradesForcedToolChoice() throws Throwable {
         assertEquals("auto", request.getParameters().getToolChoice());
     }
 
+    @Test
+    @DisplayName("DashScope chat model should ignore a null request when degrading")
+    void testDegradeForcedToolChoiceWithNullRequest() throws Throwable {
+        DashScopeChatModel chatModel =
+                DashScopeChatModel.builder()
+                        .apiKey(mockApiKey)
+                        .modelName("qwen-plus")
+                        .enableThinking(true)
+                        .build();
+
+        assertDoesNotThrow(() -> invokeDegradeForcedToolChoiceForThinkingMode(chatModel, null));
+    }
+
+    @Test
+    @DisplayName("DashScope chat model should ignore missing parameters when degrading")
+    void testDegradeForcedToolChoiceWithNullParameters() throws Throwable {
+        DashScopeChatModel chatModel =
+                DashScopeChatModel.builder()
+                        .apiKey(mockApiKey)
+                        .modelName("qwen-plus")
+                        .enableThinking(true)
+                        .build();
+
+        assertDoesNotThrow(
+                () ->
+                        invokeDegradeForcedToolChoiceForThinkingMode(
+                                chatModel, DashScopeRequest.builder().build()));
+    }
+
     @Test
     @DisplayName("DashScope chat model apply thinking mode with null")
     void testApplyThinkingModeWithNull() {
@@ -1261,4 +1290,24 @@ private void invokeApplyThinkingMode(
             throw e.getTargetException();
         }
     }
+
+    /**
+     * Use reflection to invoke degradeForcedToolChoiceForThinkingMode.
+     *
+     * @param model the dashscope model
+     * @param request the dashscope API request DTO
+     * @throws Throwable throw the target exception
+     */
+    private void invokeDegradeForcedToolChoiceForThinkingMode(
+            DashScopeChatModel model, DashScopeRequest request) throws Throwable {
+        try {
+            Method method =
+                    DashScopeChatModel.class.getDeclaredMethod(
+                            "degradeForcedToolChoiceForThinkingMode", DashScopeRequest.class);
+            method.setAccessible(true);
+            method.invoke(model, request);
+        } catch (InvocationTargetException e) {
+            throw e.getTargetException();
+        }
+    }
 }