assertEquals("underscore", ResourceUtil.resolve(value));

        // Clean up test properties
        System.clearProperty("var1");
        System.clearProperty("var2");
        System.clearProperty("special");
        System.clearProperty("123");
        System.clearProperty("test_var");
    }

    @Test
    public void test_resolve_edgeCases() {
        // Test empty property replacement

            String floatValue = fessConfig.get(floatKey);
            assertEquals("45.67", floatValue);
        } finally {
            System.clearProperty(Constants.FESS_CONFIG_PREFIX + intKey);
            System.clearProperty(Constants.FESS_CONFIG_PREFIX + floatKey);
        }
    }

    // Test getting boolean configuration values
    @Test
    public void test_get_booleanValues() {

    public void test_getSearchEngineHttpAddress_null() {
        // Clear the system property to test null case
        String originalValue = System.getProperty(Constants.FESS_SEARCH_ENGINE_HTTP_ADDRESS);
        System.clearProperty(Constants.FESS_SEARCH_ENGINE_HTTP_ADDRESS);

        try {
            String result = SystemUtil.getSearchEngineHttpAddress();
            assertNull(result);
        } finally {

        assertTrue(cmdList.contains("-Dapp.module.feature2=disabled"));

        // Clean up
        System.clearProperty("app.module.feature1");
        System.clearProperty("app.module.feature2");
        System.clearProperty("app.service.api");
        System.clearProperty("config.app.module");
    }

    // Test invalid regex in custom properties
    @Test

            assertFalse(content.contains("${fess.dictionary.path}"));
        } finally {
            // Restore original property
            if (originalPath.isEmpty()) {
                System.clearProperty("fess.dictionary.path");
            } else {
                System.setProperty("fess.dictionary.path", originalPath);
            }
        }
    }

    @Test

            assertEquals(Constants.PROCESS_TYPE_REPLACE, ptList.get(0));
        } finally {
            System.clearProperty("lasta.env");
        }
    }

    @Test
    public void test_getProcessTypeList_defaultMode() {
        System.clearProperty("lasta.env");
        final List<String> ptList = pathMappingHelper.getProcessTypeList();
        assertEquals(2, ptList.size());

        }
    }

    @Override
    protected void tearDown(TestInfo testInfo) throws Exception {
        // Clean up system properties
        System.clearProperty("fess.search_engine.http_address");
        System.clearProperty("fesen.http.url");
        super.tearDown(testInfo);
    }

        confDir = Files.createDirectories(tempDir.resolve("conf"));
    }

    @Override
    protected void tearDown(TestInfo testInfo) throws Exception {
        System.clearProperty("fess.var.path");
        System.clearProperty("fess.webapp.path");
        System.clearProperty("fess.conf.path");
        if (tempDir != null) {
            deleteRecursively(tempDir.toFile());
        }
        super.tearDown(testInfo);
    }

        try {
            suggestJob.executeSuggestCreator();
        } catch (Exception e) {
            // May fail in test environment
        } finally {
            System.clearProperty("os.name");
        }

        List<String> cmdList = mockProcessHelper.getLastCommandList();
        if (cmdList != null && cmdList.size() > 0) {

            assertEquals(customDir.getAbsolutePath(), manager.baseDir.getAbsolutePath());
            assertTrue(customDir.exists());
            manager.destroy();
        } finally {
            System.clearProperty(Constants.FESS_THUMBNAIL_PATH);
        }
    }

    // Test initialization with var path
    @Test
    public void test_init_withVarPath() {
        File varDir = new File(tempDir, "var");