Basic let bindings 🎞

1 files changed, 38 insertions, 0 deletions

diff --git a/src/parse/tests.rs b/src/parse/tests.rs
index b9a3d301..9460db6b 100644
--- a/src/parse/tests.rs
+++ b/src/parse/tests.rs
@@ -202,6 +202,21 @@ macro_rules! Block {
     };
 }
 
+macro_rules! Let {
+    (@$pat:expr $(=> $expr:expr)?) => {{
+        #[allow(unused)]
+        let mut expr = None;
+        $(expr = Some(Box::new(into!($expr)));)?
+        Expr::Let(ExprLet {
+            pat: into!($pat).map(|s: &str| Ident(s.into())),
+            expr
+        })
+    }};
+    ($($tts:tt)*) => {
+        Node::Expr(Let!(@$($tts)*))
+    };
+}
+
 #[test]
 fn test_parse_comments() {
     // In markup.
@@ -651,3 +666,26 @@ fn test_parse_values() {
         nodes: [],
         errors: [S(1..3, "expected expression, found invalid token")]);
 }
+
+#[test]
+fn test_parse_let_bindings() {
+    // Basic let.
+    t!("#let x;" Let!("x"));
+    t!("#let _y=1;" Let!("_y" => Int(1)));
+
+    // Followed by text.
+    t!("#let x = 1\n+\n2;\nHi there"
+        Let!("x" => Binary(Int(1), Add, Int(2))),
+        Space, Text("Hi"), Space, Text("there"));
+
+    // Missing semicolon.
+    t!("#let x = a\nHi"
+        nodes: [Let!("x" => Id("a"))],
+        errors: [S(11..13, "unexpected identifier"),
+                 S(13..13, "expected semicolon")]);
+
+    // Missing identifier.
+    t!("#let 1;"
+        nodes: [],
+        errors: [S(5..6, "expected identifier, found integer")])
+}