### Question:
ModeProcessor { static String processModeType(ModeType modeType, String input) { if (modeType == null || input == null || input.isEmpty()) { return input; } switch (modeType) { case FORWARD: input = input.replace("\\", "/"); break; case DOUBLE: input = input.replace("\\", "\\\\"); input = input.replace(":", "\\:"); break; case POLICY: input = input.replace(File.separator, "${/}"); break; default: _logger.log(Level.WARNING, SLogger.NO_PROCESSOR_DEFINED, modeType.toString()); break; } return input; }    }### Answer:
@Test public void testNullInput() { String outputStr = ModeProcessor.processModeType(ModeType.DOUBLE, null); Assert.assertNull(outputStr); }
@Test public void testInvalidMode() { String inputStr = "TEST"; Assert.assertEquals(inputStr, ModeProcessor.processModeType(null, inputStr)); }
@Test public void testEmptyInput() { String outputStr = ModeProcessor.processModeType(ModeType.DOUBLE, ""); Assert.assertTrue(outputStr.isEmpty()); }
@Test public void testForwardMode() { String inputStr = "First Slash \\ Second Double Slash \\\\"; String expectedOutput = "First Slash / Second Double Slash String outputStr = ModeProcessor.processModeType(ModeType.FORWARD, inputStr); Assert.assertEquals(outputStr, expectedOutput); }
@Test public void testDoubleMode() { String inputStr = "First Slash \\ First Colon : Second Double Slash \\\\ Second Double Colon ::"; String expectedOutput = "First Slash \\\\ First Colon \\: Second Double Slash \\\\\\\\ Second Double Colon \\:\\:"; String outputStr = ModeProcessor.processModeType(ModeType.DOUBLE, inputStr); Assert.assertEquals(outputStr, expectedOutput); }
@Test public void testPolicyMode() { StringBuilder builder = new StringBuilder(); builder.append("First Separator "); builder.append(File.separator); builder.append(" Second Double Separator "); builder.append(File.separator); builder.append(File.separator); String expectedOutput = "First Separator ${/} Second Double Separator ${/}${/}"; String outputStr = ModeProcessor.processModeType(ModeType.POLICY, builder.toString()); Assert.assertEquals(outputStr, expectedOutput); }