update tests

tests/wgsl-errors.rs

@@ -1624,13 +1624,56 @@ fn assign_to_let() {
         }
         ",
         r###"error: invalid left-hand side of assignment
-  ┌─ wgsl:4:10
+  ┌─ wgsl:3:17
   │
+3 │             let a = 10;
+  │                 ^ this is an immutable binding
 4 │             a = 20;
   │             ^ cannot assign to this expression
   │
-  = note: 'a' is an immutable binding
-  = note: consider declaring it with `var` instead of `let`
+  = note: consider declaring 'a' with `var` instead of `let`
+
+"###,
+    );
+
+    check(
+        "
+        fn f() {
+            let a = array(1, 2);
+			a[0] = 1;
+        }
+        ",
+        r###"error: invalid left-hand side of assignment
+  ┌─ wgsl:3:17
+  │
+3 │             let a = array(1, 2);
+  │                 ^ this is an immutable binding
+4 │             a[0] = 1;
+  │             ^^^^ cannot assign to this expression
+  │
+  = note: consider declaring 'a' with `var` instead of `let`
+
+"###,
+    );
+
+    check(
+        "
+        struct S { a: i32 }
+
+        fn f() {
+            let a = S(10);
+	        a.a = 20;
+        }
+        ",
+        r###"error: invalid left-hand side of assignment
+  ┌─ wgsl:5:17
+  │
+5 │             let a = S(10);
+  │                 ^ this is an immutable binding
+6 │             a.a = 20;
+  │             ^^^ cannot assign to this expression
+  │
+  = note: consider declaring 'a' with `var` instead of `let`
 
 "###,
     );