From dbc307455632ba6d51899c0cbe5df0fb897e361b Mon Sep 17 00:00:00 2001
From: Jeff Muizelaar <jrmuizel@gmail.com>
Date: Sun, 3 Feb 2019 10:06:09 -0500
Subject: [PATCH] Make sure we match the entire pattern

---
 crates/ra_mbe/src/lib.rs          | 32 ++++++++++++++++++++++++++++++-
 crates/ra_mbe/src/mbe_expander.rs |  3 +++
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/crates/ra_mbe/src/lib.rs b/crates/ra_mbe/src/lib.rs
index 922256c03b..ec12192cc5 100644
--- a/crates/ra_mbe/src/lib.rs
+++ b/crates/ra_mbe/src/lib.rs
@@ -176,7 +176,7 @@ impl_froms!(TokenTree: Leaf, Subtree);
     }
 
     #[test]
-    fn test_fail_match_pattern_by_token() {
+    fn test_fail_match_pattern_by_first_token() {
         let macro_definition = r#"
         macro_rules! foo {
             ($ i:ident) => (
@@ -206,4 +206,34 @@ impl_froms!(TokenTree: Leaf, Subtree);
         assert_expansion(&rules, "foo! { + Baz }", "struct Baz ;");
     }
 
+    #[test]
+    fn test_fail_match_pattern_by_last_token() {
+        let macro_definition = r#"
+        macro_rules! foo {
+            ($ i:ident) => (
+                mod $ i {}
+            );
+            ($ i:ident =) => (
+                fn $ i() {}
+            );
+            ($ i:ident +) => (
+                struct $ i;
+            )
+        }
+"#;
+
+        let source_file = ast::SourceFile::parse(macro_definition);
+        let macro_definition = source_file
+            .syntax()
+            .descendants()
+            .find_map(ast::MacroCall::cast)
+            .unwrap();
+
+        let definition_tt = ast_to_token_tree(macro_definition.token_tree().unwrap()).unwrap();
+        let rules = crate::MacroRules::parse(&definition_tt).unwrap();
+
+        assert_expansion(&rules, "foo! { foo }", "mod foo {}");
+        assert_expansion(&rules, "foo! { bar = }", "fn bar () {}");
+        assert_expansion(&rules, "foo! { Baz + }", "struct Baz ;");
+    }
 }
diff --git a/crates/ra_mbe/src/mbe_expander.rs b/crates/ra_mbe/src/mbe_expander.rs
index af5beb786c..2945e73590 100644
--- a/crates/ra_mbe/src/mbe_expander.rs
+++ b/crates/ra_mbe/src/mbe_expander.rs
@@ -13,6 +13,9 @@ pub(crate) fn exapnd(rules: &crate::MacroRules, input: &tt::Subtree) -> Option<t
 fn expand_rule(rule: &crate::Rule, input: &tt::Subtree) -> Option<tt::Subtree> {
     let mut input = TtCursor::new(input);
     let bindings = match_lhs(&rule.lhs, &mut input)?;
+    if !input.is_eof() {
+        return None;
+    }
     expand_subtree(&rule.rhs, &bindings, &mut Vec::new())
 }