diff --git a/Partner-Core/src/test/java/work/slhaf/partner/core/action/runner/execution/CommandExecutionServiceTest.java b/Partner-Core/src/test/java/work/slhaf/partner/core/action/runner/execution/CommandExecutionServiceTest.java
new file mode 100644
index 00000000..86f028fd
--- /dev/null
+++ b/Partner-Core/src/test/java/work/slhaf/partner/core/action/runner/execution/CommandExecutionServiceTest.java
@@ -0,0 +1,93 @@
+package work.slhaf.partner.core.action.runner.execution;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+class CommandExecutionServiceTest {
+
+    private final CommandExecutionService service = new CommandExecutionService();
+
+    @Test
+    void testBuildFileExecutionCommandsWithOrderedParams() {
+        Map<String, Object> params = new LinkedHashMap<>();
+        params.put("name", "demo");
+        params.put("count", 2);
+
+        String[] commands = service.buildFileExecutionCommands("python3", params, "/tmp/demo.py");
+
+        Assertions.assertArrayEquals(
+                new String[]{"python3", "/tmp/demo.py", "--name=demo", "--count=2"},
+                commands
+        );
+    }
+
+    @Test
+    void testFileCommandsAndExecution() throws IOException {
+
+        String content = "print(111)";
+
+        Path file = Path.of("/tmp/demo.py");
+        Files.writeString(file, "print(111)\n");
+
+        CommandExecutionService.Result catResult = service.exec("cat", "/tmp/demo.py");
+        System.out.println(catResult.toString());
+        Assertions.assertEquals(content, catResult.getTotal());
+
+        String[] commands = service.buildFileExecutionCommands("python3", null, "/tmp/demo.py");
+
+        CommandExecutionService.Result execResult = service.exec(commands);
+        System.out.println(execResult.toString());
+        Assertions.assertEquals("111", execResult.getTotal());
+    }
+
+    @Test
+    void testExecListCollectsStdoutLines() {
+        CommandExecutionService.Result result = service.exec(List.of(
+                "sh", "-lc", "printf 'hello\\nworld\\n'"
+        ));
+
+        Assertions.assertTrue(result.isOk());
+        Assertions.assertEquals(List.of("hello", "world"), result.getResultList());
+        Assertions.assertEquals("hello\nworld", result.getTotal());
+    }
+
+    @Test
+    void testExecVarargsCollectsStdout() {
+        CommandExecutionService.Result result = service.exec(
+                "sh", "-lc", "printf 'ok'"
+        );
+
+        Assertions.assertTrue(result.isOk());
+        Assertions.assertEquals(List.of("ok"), result.getResultList());
+        Assertions.assertEquals("ok", result.getTotal());
+    }
+
+    @Test
+    void testExecReturnsStderrWhenCommandFailsWithoutStdout() {
+        CommandExecutionService.Result result = service.exec(
+                "sh", "-lc", "echo fail >&2; exit 7"
+        );
+
+        Assertions.assertFalse(result.isOk());
+        Assertions.assertEquals(List.of("fail"), result.getResultList());
+        Assertions.assertEquals("fail", result.getTotal());
+    }
+
+    @Test
+    void testExecPrefersStdoutWhenStdoutAndStderrBothExist() {
+        CommandExecutionService.Result result = service.exec(
+                "sh", "-lc", "echo out; echo err >&2; exit 0"
+        );
+
+        Assertions.assertTrue(result.isOk());
+        Assertions.assertEquals(List.of("out"), result.getResultList());
+        Assertions.assertEquals("out", result.getTotal());
+    }
+}