Refactor DecoderUtilTest

@RunWith(K9LibRobolectricTestRunner.class)

public class DecoderUtilTest {

    private String body, expect;

    private MimeMessage message;

    @Test

    public void decodeEncodedWords_with_unencoded_data_returns_original_text() {

        body = "abc";

        expect = "abc";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("abc", "abc");

    }

    @Test

    public void decodeEncodedWords_withAsciiCharset_encoded_data_returns_text() {

        body = "=?us-ascii?q?abc?=";

        expect = "abc";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=?us-ascii?q?abc?=", "abc");

    }

    @Test

    public void decodeEncodedWords_withStartOnly_encoding_format_returnAsText() {

        body = "=?";

        expect = "=?";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=?", "=?");

    }

    @Test

    public void decodeEncodedWords_withStartAndSeparatorOnly_returnAsText() {

        body = "=??";

        expect = "=??";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=??", "=??");

    }

    @Test

    public void decodeEncodedWords_withStartAnd2SeparatorOnly_returnAsText() {

        body = "=???";

        expect = "=???";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=???", "=???");

    }

    @Test

    public void decodeEncodedWords_withStartAnd3SeparatorOnly_returnAsText() {

        body = "=????";

        expect = "=????";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=????", "=????");

    }

    @Test

    public void decodeEncodedWords_withSeparatorsOnly_returnAsText() {

        body = "=????=";

        expect = "=????=";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=????=", "=????=");

    }

    @Test

    public void decodeEncodedWords_withMissingCharset_returnAsText() {

        body = "=??q??=";

        expect = "=??q??=";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=??q??=", "=??q??=");

    }

    @Test

    public void decodeEncodedWords_withTextAndMissingCharset_returnAsText() {

        body = "=??q?a?=";

        expect = "a";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=??q?a?=", "a");

    }

    @Test

    public void decodeEncodedWords_withNoTextCharsetOrEncoding_returnAsText() {

        body = "=??=";

        expect = "=??=";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=??=", "=??=");

    }

    @Test

    public void decodeEncodedWords_with_MissingEncodingAndData_returnAsText() {

        body = "=?x?=";

        expect = "=?x?=";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=?x?=", "=?x?=");

    }

    @Test

    public void decodeEncodedWords_withMissingEncoding_returnAsText() {

        body = "=?x??=";

        expect = "=?x??=";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=?x??=", "=?x??=");

    }

    @Test

    public void decodeEncodedWords_with_incompleteEncodingFormat_returnAsText() {

        body = "=?x?q?=";

        expect = "=?x?q?=";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=?x?q?=", "=?x?q?=");

    }

    @Test

    public void decodeEncodedWords_with_unrecognisedEncoding_withEmptyEncodedData_returnAsText() {

        body = "=?x?q??=";

        expect = "=?x?q??=";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=?x?q??=", "=?x?q??=");

    }

    @Test

    public void decodeEncodedWords_withUnrecognisedEncoding_withEncodedData_return_encoded_data() {

        body = "=?x?q?X?=";

        expect = "X";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=?x?q?X?=", "X");

    }

    @Test

    public void decodeEncodedWords_withInvalidBase64String_returnsEmptyString() {

        body = "=?us-ascii?b?abc?=";

        expect = "";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=?us-ascii?b?abc?=", "");

    }

    @Test

    public void decodeEncodedWords_withPartiallyEncoded_returnsBothSections() {

        body = "=?us-ascii?q?abc?= =?";

        expect = "abc =?";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=?us-ascii?q?abc?= =?", "abc =?");

    }

    @Test

    public void decodeEncodedWords_withPartiallyEncodedAfter_returnsBothSections() {

        body = "def=?us-ascii?q?abc?=";

        expect = "defabc";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("def=?us-ascii?q?abc?=", "defabc");

    }

    @Test

    public void decodeEncodedWords_withUnrecognisedCharset_returnsEncodedData() {

        body = "=?x?= =?";

        expect = "=?x?= =?";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=?x?= =?", "=?x?= =?");

    }

    @Test

    public void decodeEncodedWords_withMultipleEncodedSections_decodesBoth() {

        body = "=?us-ascii?q?abc?= =?us-ascii?q?def?=";

        expect = "abcdef";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("=?us-ascii?q?abc?= =?us-ascii?q?def?=", "abcdef");

    }

    @Test

    public void decodeEncodedWords_withMultipleEncodedSections_decodesSequentialSectionTogether() {

        //Splitting mid-character is RFC2047 non-compliant but seen in practice.

        body = "=?utf-8?B?5Liq5Lq66YKu566xOkJVRyAjMzAyNDY6OumCruS7tuato+aWh+mZhOS7tuWQ?=\n" +

        String input = "=?utf-8?B?5Liq5Lq66YKu566xOkJVRyAjMzAyNDY6OumCruS7tuato+aWh+mZhOS7tuWQ?=\n" +

                "=?utf-8?B?jeensOecgeeVpeaYvuekuuS8mOWMlg==?=";

        expect = "个人邮箱:BUG #30246::邮件正文附件名称省略显示优化";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected(input, "个人邮箱:BUG #30246::邮件正文附件名称省略显示优化");

    }

    @Test

    public void decodeEncodedWords_withGB2312_decodes_correctly() {

        body = "=?gb2312?B?Obv9t9az6cnu29rHsLqju6rHyLPHSlfN8rrAvsa16qOsuPzT0DIwvNIzOTnU?= " +

        String input = "=?gb2312?B?Obv9t9az6cnu29rHsLqju6rHyLPHSlfN8rrAvsa16qOsuPzT0DIwvNIzOTnU?= " +

                "=?gb2312?B?qr6r0aG439DHytTLr77Gteq1yMTjwLSjoaOoQUSjqQ?=";

        expect = "9积分抽深圳前海华侨城JW万豪酒店，更有20家399元精选高星试睡酒店等你来！（AD�";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected(input, "9积分抽深圳前海华侨城JW万豪酒店，更有20家399元精选高星试睡酒店等你来！（AD�");

    }

    @Test

    public void decodeEncodedWords_withRFC2047examples_decodesCorrectly() {

        body = "(=?ISO-8859-1?Q?a?=)";

        expect = "(a)";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        body = "(=?ISO-8859-1?Q?a?= b)";

        expect = "(a b)";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        body = "(=?ISO-8859-1?Q?a?= =?ISO-8859-1?Q?b?=)";

        expect = "(ab)";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        body = "(=?ISO-8859-1?Q?a?=  =?ISO-8859-1?Q?b?=)";

        expect = "(ab)";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        body = "(=?ISO-8859-1?Q?a?=     \n    =?ISO-8859-1?Q?b?=)";

        expect = "(ab)";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        body = "(=?ISO-8859-1?Q?a_b?=)";

        expect = "(a b)";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        body = "(=?ISO-8859-1?Q?a?= =?ISO-8859-2?Q?_b?=)";

        expect = "(a b)";

        message = null;

        assertEquals(expect, DecoderUtil.decodeEncodedWords(body, message));

        assertInputDecodesToExpected("(=?ISO-8859-1?Q?a?=)", "(a)");

        assertInputDecodesToExpected("(=?ISO-8859-1?Q?a?= b)", "(a b)");

        assertInputDecodesToExpected("(=?ISO-8859-1?Q?a?= =?ISO-8859-1?Q?b?=)", "(ab)");

        assertInputDecodesToExpected("(=?ISO-8859-1?Q?a?=  =?ISO-8859-1?Q?b?=)", "(ab)");

        assertInputDecodesToExpected("(=?ISO-8859-1?Q?a?=     \n    =?ISO-8859-1?Q?b?=)", "(ab)");

        assertInputDecodesToExpected("(=?ISO-8859-1?Q?a_b?=)", "(a b)");

        assertInputDecodesToExpected("(=?ISO-8859-1?Q?a?= =?ISO-8859-2?Q?_b?=)", "(a b)");

    }

    private void assertInputDecodesToExpected(String input, String expected) {

        String decodedText = DecoderUtil.decodeEncodedWords(input, null);

        assertEquals(expected, decodedText);

    }

}