From 57e6ef0bfbfda17276f7f9c62abee81f3f086f91 Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Sun, 12 Dec 2021 19:22:37 +0300
Subject: [PATCH] tighten up invariants

---
 crates/mbe/src/to_parser_tokens.rs |  4 +++-
 crates/parser/src/tokens.rs        |  7 ++-----
 crates/syntax/src/parsing.rs       | 20 ++++++++++++--------
 3 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/crates/mbe/src/to_parser_tokens.rs b/crates/mbe/src/to_parser_tokens.rs
index 435226342ec..644689f432a 100644
--- a/crates/mbe/src/to_parser_tokens.rs
+++ b/crates/mbe/src/to_parser_tokens.rs
@@ -62,7 +62,9 @@ pub(crate) fn to_parser_tokens(buffer: &TokenBuffer) -> parser::Tokens {
                         let kind = SyntaxKind::from_char(punct.char)
                             .unwrap_or_else(|| panic!("{:#?} is not a valid punct", punct));
                         res.push(kind);
-                        res.was_joint(punct.spacing == tt::Spacing::Joint);
+                        if punct.spacing == tt::Spacing::Joint {
+                            res.was_joint();
+                        }
                     }
                 }
                 cursor.bump()
diff --git a/crates/parser/src/tokens.rs b/crates/parser/src/tokens.rs
index de831f0f705..1128cfe99d6 100644
--- a/crates/parser/src/tokens.rs
+++ b/crates/parser/src/tokens.rs
@@ -51,11 +51,8 @@ impl Tokens {
     /// tokens.push(curr_joint)
     /// ```
     #[inline]
-    pub fn was_joint(&mut self, yes: bool) {
-        let idx = self.len();
-        if yes && idx > 0 {
-            self.set_joint(idx - 1);
-        }
+    pub fn was_joint(&mut self) {
+        self.set_joint(self.len() - 1);
     }
     #[inline]
     pub fn push_ident(&mut self, contextual_kw: SyntaxKind) {
diff --git a/crates/syntax/src/parsing.rs b/crates/syntax/src/parsing.rs
index 5cafe70dd7d..865e146482c 100644
--- a/crates/syntax/src/parsing.rs
+++ b/crates/syntax/src/parsing.rs
@@ -58,18 +58,22 @@ pub(crate) fn parse_text_as<T: AstNode>(
 pub(crate) fn to_parser_tokens(text: &str, lexer_tokens: &[lexer::Token]) -> ::parser::Tokens {
     let mut off = 0;
     let mut res = parser::Tokens::default();
-    let mut was_joint = true;
+    let mut was_joint = false;
     for t in lexer_tokens {
         if t.kind.is_trivia() {
             was_joint = false;
-        } else if t.kind == SyntaxKind::IDENT {
-            let token_text = &text[off..][..usize::from(t.len)];
-            let contextual_kw =
-                SyntaxKind::from_contextual_keyword(token_text).unwrap_or(SyntaxKind::IDENT);
-            res.push_ident(contextual_kw);
         } else {
-            res.was_joint(was_joint);
-            res.push(t.kind);
+            if t.kind == SyntaxKind::IDENT {
+                let token_text = &text[off..][..usize::from(t.len)];
+                let contextual_kw =
+                    SyntaxKind::from_contextual_keyword(token_text).unwrap_or(SyntaxKind::IDENT);
+                res.push_ident(contextual_kw);
+            } else {
+                if was_joint {
+                    res.was_joint();
+                }
+                res.push(t.kind);
+            }
             was_joint = true;
         }
         off += usize::from(t.len);