Selectors Serialization Format for Testing (SSFT) Specification

Serializing Tokens

To normalize an IDENT (n), the following algorithm MUST be used:

1. Replace the escape sequences (\ and following characters) in n by characters represented by them respectively.
2. If there is any character that is not one of U+002D HYPHEN-MINUS (-), U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), U+0041 LATIN CAPITAL LETTER A (A) to U+005A LATIN CAPITAL LETTER Z (Z), U+005F LOW LINE (_), U+0061 LATIN SMALL LETTER A (a) to U+006A LATIN SMALL LETTER Z (z), U+0080 to U+D7FF, or U+E000 to U+10FFFF in n, then replace it by string \HHHHHH, where HHHHHH is the upper‐case zero‐padded hexadecimal representation of the character. If the character is outside the range of [U+0000, U+10FFFF], HHHHHH MUST be FFFFFF.
3. If the first character in n is one of U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), then prepend a string \00003 at the beginning of n.
4. If the first character in n is U+002D HYPHEN-MINUS (-) and the second character, if any, is not one of U+0041 LATIN CAPITAL LETTER A (A) to U+005A LATIN CAPITAL LETTER Z (Z), U+005F LOW LINE (_), U+0061 LATIN SMALL LETTER A (a) to U+006A LATIN SMALL LETTER Z (z), U+0080 to U+D7FF, or U+E000 to U+10FFFF, or n is equal to U+002D HYPHEN-MINUS (-), then replace the U+002D HYPHEN-MINUS (-) character by string \00002D.
5. Then, n is the result of the algorithm.

To normalize a STRING (s), the following algorithm MUST be used:

1. Replace the escape sequences (\ and following characters) in s by characters represented by them (or an empty string if \ is immediately followed by newline character(s)) respectively.

2. Remove the quotation characters in s if s is a STRING.

   The input s to this algorithm may be an IDENT.

3. If there is any character that is not one of U+0020 SPACE, U+0021 EXCLAMATION MARK (!), U+0023 NUMBER SIGN (#) to U+005B LEFT SQUARE BRACKET, U+005D RIGHT SQUARE BRACKET to U+D7FF, or U+E000 to U+10FFFF in s, then replace it by string \HHHHHH, where HHHHHH is the upper‐case zero‐padded hexadecimal representation of the character. If the character is outside the range of [U+0000, U+10FFFF], HHHHHH MUST be FFFFFF.

4. Insert a U+0022 QUOTATION MARK (") at the beginning of s.

5. Insert a U+0022 QUOTATION MARK (") at the end of s.

6. Then, s is the result of the algorithm.

A newline SHOULD be represented as a U+000A LINE FEED character. However, depending on the context where the SSFT representation is in use, a sequence of U+000D CARRIAGE RETURN followed by a U+000A LINE FEED (i.e. a CRLF sequence) or a character U+000D CARRIAGE RETURN MAY be used as a newline instead. Newline representations SHOULD be consistent in an SSFT representation.

Serializing Simple Selectors

No SSFT representation is defined for an invalid simple selector selector.

To serialize a simple selector (ss), the following algorithm MUST be used:

If ss is a type or universal selector

1. If a namespace URI is specified (via namespace prefix, or by omitting namespace prefix where a default namespace is specified)

   @@

   If the null namespace is specified (by zero‐length namespace prefix)

   Append a U+007C VERTICAL BAR (|) character to result.

   If no namespace is specified (by namespace prefix *, or by omitting namespace prefix where no default namespace is specified)

   Append a U+002A ASTERISK (*) character, followed by a U+007C VERTICAL BAR (|) character, to result.

2. If ss is a type selector, append the normalized local name to result.
3. If ss is a universal selector, append a U+002A ASTERISK (*) character to result.

If ss is an attribute selector

1. Append a U+005B LEFT SQUARE BRACKET ([) to result.
2. Append a namespace prefix as following:

   If a namespace URI is specified

   @@

   @@ Current reference implementation is wrong, since its result of sorting depends on namespace prefix.

   If the null namespace is specified

   Append a U+007C VERTICAL BAR character to result.

   If no namespace is specified

   Append a U+002A ASTERISK (*) character, followed by a U+007C VERTICAL BAR (|) character, to result.

3. Append the normalized local name to result.
4. If a value is specified in ss:
   1. Depending on the way to match, append =, ~=, |=, ^=, $=, or *= to result.
   2. Append the normalized value to result.
5. Append a U+005D RIGHT SQUARE BRACKET (]) to result.

If ss is a class selector

Append a U+002E FULL STOP (.) character, followed by normalized class name, result.

If ss is an ID selector

Append a U+0023 NUMBER SIGN (#) character, followed by normalized ID, to result.

If ss is a pseudo‐class selector

1. Append a U+003A COLON (:) character to result.
2. Append the normalized name of the pseudo‐class to result.
3. Append any arguments as following:

   If the name of the pseudo‐class is lang

   1. Append a U+0028 LEFT PARENTHESIS (() character to result.
   2. Append the normalized language tag (the argument) to result.
   3. Append a U+0029 RIGHT PARENTHESIS ()) character to result.

   If the name of the pseudo‐class is -manakai-contains

   1. Append a U+0028 LEFT PARENTHESIS (() character to result.
   2. Append the normalized string (the argument) to result.
   3. Append a U+0029 RIGHT PARENTHESIS ()) character to result.

   If name of the pseudo‐class is either nth-child, nth-last-child, nth-of-type, or nth-last-of-type

   1. Append a U+0028 LEFT PARENTHESIS (() character to result.
   2. Append @@ normalized integer a to result. If the argument is a keyword odd or even, a is 2. If a and n is omitted, a is assumed as 0. Otherwise, if a is omitted, it is assumed as 1 (or -1, if there is a U+002D HYPHEN-MINUS (-) character).
   3. Append a U+006E LATIN SMALL LETTER N (n) character to result.
   4. Append @@ normalized integer b to result. It MUST be preceded by a sign, either U+002B PLUS SIGN (+) or U+002D HYPHEN-MINUS (-) character. If the argument is a keyword odd, b is 1. If the argument is a keyword even, b is 0. If b is omitted, it is assumed as 0. The sign of 0 MUST be U+002B PLUS SIGN (+).
   5. Append a U+0029 RIGHT PARENTHESIS ()) character to result.

   If the name of the pseudo‐class is not

   1. Append a string of U+003A COLON, U+006E LATIN SMALL LETTER N, U+006F LATIN SMALL LETTER O, U+0074 LATIN SMALL LETTER T, and U+0028 LEFT PARENTHESIS (:not(), followed by a newline, to result.
   2. Append four U+0020 SPACE characters to result.
   3. Append four U+0020 SPACE characters to result again.
   4. Serialize the simple selector specified as the argument to the not pseudo‐class.
   5. Append a newline to result.
   6. Append four U+0020 SPACE characters to result.
   7. Append a U+0029 RIGHT PARENTHESIS ()) character to result.

If ss is a pseudo‐element

1. Append two U+003A COLON characters (::) to result.
2. Append the normalized name of the pseudo‐element to result.

Serializing Groups of Selectors

No SSFT representation is defined for an invalid group of selectors.

To serialize a group of selectors (gs), the following algorithm MUST be used:

1. Let result an empty string.
2. For each selector (selector) in gs:
   1. If selector is not the first selector in the group of selectors, then append a U+002C COMMA (,) followed by a newline to result.
   2. Append four U+0020 SPACE characters to result.
   3. Process each sequence of simple selectors or combinator in selector by following algorithm:

      If it is a sequence of simle selector (sss)

      1. Serialize each simple selector in sss.
      2. sort
      3. Append a newline to result.

      If it is a combinator (c)

      1. Append two U+0020 SPACE characters to result.

      2. If c is descendant combinator (white space)

         Append a U+0020 SPACE character to result.

         If c is child combinator (>)

         Append a U+003E GREATER-THAN SIGN (>) character to result.

         If c is adjacent sibling combinator (+)

         Append a U+002B PLUS SIGN (+) character to result.

         If c is general sibling combinator (~)

         Append a U+007E TILDE (~) character to result.

      3. Append a U+0020 SPACE character to result.

3. Then, result is the SSFT representation of gs.