1 files changed, 58 insertions, 0 deletions
diff --git a/third_party/rust/glsl/tests/left_associativity.rs b/third_party/rust/glsl/tests/left_associativity.rs
new file mode 100644
index 0000000000..7e2a19cfb4
--- /dev/null
+++ b/third_party/rust/glsl/tests/left_associativity.rs
@@ -0,0 +1,58 @@
+use glsl::parser::Parse;
+use glsl::syntax;
+
+#[test]
+fn left_associativity() {
+  for (opstr, opname) in [
+    ("+", syntax::BinaryOp::Add),
+    ("&&", syntax::BinaryOp::And),
+    ("||", syntax::BinaryOp::Or),
+  ]
+  .iter()
+  {
+    let r = syntax::TranslationUnit::parse(format!(
+      "
+      void main() {{
+        x = a {op} b {op} c;
+      }}
+    ",
+      op = opstr
+    ));
+
+    let expected = syntax::TranslationUnit::from_non_empty_iter(vec![
+      syntax::ExternalDeclaration::FunctionDefinition(syntax::FunctionDefinition {
+        prototype: syntax::FunctionPrototype {
+          ty: syntax::FullySpecifiedType {
+            qualifier: None,
+            ty: syntax::TypeSpecifier {
+              ty: syntax::TypeSpecifierNonArray::Void,
+              array_specifier: None,
+            },
+          },
+          name: "main".into(),
+          parameters: Vec::new(),
+        },
+        statement: syntax::CompoundStatement {
+          statement_list: vec![syntax::Statement::Simple(Box::new(
+            syntax::SimpleStatement::Expression(Some(syntax::Expr::Assignment(
+              Box::new(syntax::Expr::Variable("x".into())),
+              syntax::AssignmentOp::Equal,
+              Box::new(syntax::Expr::Binary(
+                opname.clone(),
+                Box::new(syntax::Expr::Binary(
+                  opname.clone(),
+                  Box::new(syntax::Expr::Variable("a".into())),
+                  Box::new(syntax::Expr::Variable("b".into())),
+                )),
+                Box::new(syntax::Expr::Variable("c".into())),
+              )),
+            ))),
+          ))],
+        },
+      }),
+    ])
+    .unwrap();
+
+    assert_eq!(r, Ok(expected));
+  }
+}