feat(parse/tailwind): parse negative candidates, other misc cleanup/refactors

Author: dyc3

.github/labeler.yml

@@ -110,3 +110,8 @@ L-Grit:
 - changed-files:
   - any-glob-to-any-file:
     - crates/biome_grit_*/**
+
+L-Tailwind:
+- changed-files:
+  - any-glob-to-any-file:
+    - crates/biome_tailwind_*/**

crates/biome_parser/src/lexer.rs

@@ -201,6 +201,8 @@ pub trait Lexer<'src> {
     }
 
     /// Returns the byte at position `self.position + offset` or `None` if it is out of bounds.
+    ///
+    /// See also: [`Self::prev_byte_at`]
     #[inline]
     fn byte_at(&self, offset: usize) -> Option<u8> {
         self.source()
@@ -218,6 +220,18 @@ pub trait Lexer<'src> {
         }
     }
 
+    /// Returns the byte at position `self.position - offset` or `None` if it is out of bounds. Looks backwards instead of forwards.
+    #[inline]
+    fn prev_byte_at(&self, offset: usize) -> Option<u8> {
+        if offset > self.position() {
+            return None;
+        }
+        self.source()
+            .as_bytes()
+            .get(self.position() - offset)
+            .copied()
+    }
+
     #[inline]
     fn text_position(&self) -> TextSize {
         TextSize::try_from(self.position()).expect("Input to be smaller than 4 GB")

crates/biome_tailwind_factory/src/generated/node_factory.rs

@@ -71,6 +71,21 @@ impl<'src> TailwindLexer<'src> {
         }
     }
 
+    fn consume_token_saw_negative(&mut self, current: u8) -> TailwindSyntaxKind {
+        match current {
+            b'\n' | b'\r' | b'\t' | b' ' => self.consume_newline_or_whitespaces(),
+            bracket @ (b'[' | b']' | b'(' | b')') => self.consume_bracket(bracket),
+            _ if self.current_kind == T!['['] => self.consume_bracketed_thing(TW_SELECTOR, b']'),
+            _ if self.current_kind == T!['('] => self.consume_bracketed_thing(TW_VALUE, b')'),
+            b':' => self.consume_byte(T![:]),
+            b'-' => self.consume_byte(T![-]),
+            b'!' => self.consume_byte(T![!]),
+            b'/' => self.consume_byte(T![/]),
+            _ if current.is_ascii_alphabetic() => self.consume_base(),
+            _ => self.consume_unexpected_character(),
+        }
+    }
+
     /// Consume a token in the arbitrary context
     fn consume_token_arbitrary(&mut self, current: u8) -> TailwindSyntaxKind {
         match current {
@@ -252,6 +267,7 @@ impl<'src> Lexer<'src> for TailwindLexer<'src> {
             match self.current_byte() {
                 Some(current) => match context {
                     TailwindLexContext::Regular => self.consume_token(current),
+                    TailwindLexContext::SawNegative => self.consume_token_saw_negative(current),
                     TailwindLexContext::Arbitrary => self.consume_token_arbitrary(current),
                     TailwindLexContext::ArbitraryVariant => {
                         self.consume_token_arbitrary_variant(current)

crates/biome_tailwind_factory/src/generated/syntax_factory.rs

@@ -191,3 +191,13 @@ fn variant_multiple_full() {
         TW_VALUE:7
     );
 }
+
+#[test]
+fn negative() {
+    assert_lex!(
+        TailwindLexContext::SawNegative,
+        "-mt",
+        DASH:1,
+        TW_BASE:2,
+    );
+}

crates/biome_tailwind_parser/src/lexer/mod.rs

@@ -56,7 +56,8 @@ impl ParseSeparatedList for CandidateList {
     ) -> biome_parser::parse_recovery::RecoveryResult {
         parsed_element.or_recover_with_token_set(
             p,
-            &ParseRecoveryTokenSet::new(TW_BOGUS_CANDIDATE, token_set![WHITESPACE, NEWLINE, EOF]),
+            &ParseRecoveryTokenSet::new(TW_BOGUS_CANDIDATE, token_set![WHITESPACE])
+                .enable_recovery_on_line_break(),
             expected_candidate,
         )
     }
@@ -68,11 +69,16 @@ fn parse_full_candidate(p: &mut TailwindParser) -> ParsedSyntax {
 
     VariantList.parse_list(p);
 
+    if p.at(T![-]) {
+        p.bump_with_context(T![-], TailwindLexContext::SawNegative);
+    }
+
     let candidate = parse_arbitrary_candidate(p)
         .or_else(|| parse_functional_or_static_candidate(p))
         .or_recover_with_token_set(
             p,
-            &ParseRecoveryTokenSet::new(TW_BOGUS_CANDIDATE, token_set![WHITESPACE, NEWLINE, EOF]),
+            &ParseRecoveryTokenSet::new(TW_BOGUS_CANDIDATE, token_set![WHITESPACE])
+                .enable_recovery_on_line_break(),
             expected_candidate,
         );
 
@@ -112,10 +118,11 @@ fn parse_functional_or_static_candidate(p: &mut TailwindParser) -> ParsedSyntax
         return Present(m.complete(p, TW_STATIC_CANDIDATE));
     }
 
-    p.bump(DASH);
+    p.expect(T![-]);
     match parse_value(p).or_recover_with_token_set(
         p,
-        &ParseRecoveryTokenSet::new(TW_BOGUS_VALUE, token_set![WHITESPACE, NEWLINE, T![!], EOF]),
+        &ParseRecoveryTokenSet::new(TW_BOGUS_VALUE, token_set![WHITESPACE, T![!]])
+            .enable_recovery_on_line_break(),
         expected_value,
     ) {
         Ok(_) => {}
@@ -192,10 +199,7 @@ fn parse_modifier(p: &mut TailwindParser) -> ParsedSyntax {
     }
     match parse_value(p).or_recover_with_token_set(
         p,
-        &ParseRecoveryTokenSet::new(
-            TW_BOGUS_MODIFIER,
-            token_set![WHITESPACE, NEWLINE, T![!], EOF],
-        ),
+        &ParseRecoveryTokenSet::new(TW_BOGUS_MODIFIER, token_set![WHITESPACE, NEWLINE, T![!]]),
         expected_value,
     ) {
         Ok(_) => {}

crates/biome_tailwind_parser/src/lexer/tests.rs

@@ -79,6 +79,10 @@ impl ParseSeparatedList for VariantList {
 }
 
 pub(crate) fn parse_variant(p: &mut TailwindParser) -> ParsedSyntax {
+    if p.at(T![-]) {
+        // variants can't start with a negative sign
+        return Absent;
+    }
     if p.at(T!['[']) {
         return parse_arbitrary_variant(p);
     }

crates/biome_tailwind_parser/src/syntax/mod.rs

@@ -22,6 +22,8 @@ pub(crate) enum TailwindLexContext {
     /// The default state.
     #[default]
     Regular,
+    /// The parser just encountered a `-` before a basename, e.g. in `-mt-4`. That meant that the next token should be a basename.
+    SawNegative,
     /// The lexer has encountered a `[` and the parser has yet to encounter the matching `]`.
     Arbitrary,
     /// Like Arbitrary, but specifically for arbitrary variants.

crates/biome_tailwind_parser/src/syntax/variant.rs

@@ -18,6 +18,7 @@ TwRoot {
     candidates: TwCandidateList [
         TwFullCandidate {
             variants: TwVariantList [],
+            negative_token: missing (optional),
             candidate: TwBogusCandidate {
                 items: [
                     L_BRACKET@0..1 "[" [] [],
@@ -30,6 +31,7 @@ TwRoot {
         WHITESPACE@7..8 " " [] [],
         TwFullCandidate {
             variants: TwVariantList [],
+            negative_token: missing (optional),
             candidate: TwFunctionalCandidate {
                 base_token: TW_BASE@8..9 "w" [] [],
                 minus_token: DASH@9..10 "-" [] [],
@@ -53,21 +55,23 @@ TwRoot {
   1: [email protected]
     0: [email protected]
       0: [email protected]
-      1: [email protected]
+      1: (empty)
+      2: [email protected]
         0: [email protected] "[" [] []
         1: [email protected] ":40px" [] []
         2: [email protected] "]" [] []
-      2: (empty)
+      3: (empty)
     1: [email protected] " " [] []
     2: [email protected]
       0: [email protected]
-      1: [email protected]
+      1: (empty)
+      2: [email protected]
         0: [email protected] "w" [] []
         1: [email protected] "-" [] []
         2: [email protected]
           0: [email protected] "5" [] [Newline("\n")]
         3: (empty)
-      2: (empty)
+      3: (empty)
   2: [email protected] "" [] []
 
 ```