Check expression is tuple

1 files changed, 24 insertions, 1 deletions

diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerAssignTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerAssignTests.java
index 20f3ef5d..b71db8f7 100644
--- a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerAssignTests.java
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerAssignTests.java
@@ -85,7 +85,7 @@ public class TypeCheckerAssignTests {
         ));
         var context = TypeCheckerContext.EMPTY
             .enterNamespace(P.map(
-                Map.entry("x", Variable.defined(tupleType, VariableType.VAR))
+                Map.entry("x", Variable.defined(tupleType, VariableType.VAL))
             ));
 
         var typed = typeCheckFunctionStatement(untyped, context);
@@ -100,6 +100,29 @@ public class TypeCheckerAssignTests {
         ));
     }
 
+    @Test
+    public void givenExpressionIsNotTupleWhenTargetIsTupleThenErrorIsThrown() {
+        var untyped = Untyped.assign(
+            Untyped.targetTuple(List.of(
+                Untyped.targetVal("a"),
+                Untyped.targetVal("b")
+            )),
+            Untyped.reference("x")
+        );
+        var context = TypeCheckerContext.EMPTY
+            .enterNamespace(P.map(
+                Map.entry("x", Variable.defined(Types.INT, VariableType.VAL))
+            ));
+
+        var error = assertThrows(
+            UnexpectedTypeError.class,
+            () -> typeCheckFunctionStatement(untyped, context)
+        );
+
+        assertThat(error.actual(), equalTo(Types.INT));
+        assertThat(error.expected(), equalTo(TypeSets.TUPLE));
+    }
+
     private static TypeCheckerResult<? extends TypedFunctionStatementNode> typeCheckFunctionStatement(
         UntypedFunctionStatementNode untyped,
         TypeCheckerContext context