fixing casts unit tests

test/casts.zig

@@ -9,9 +9,7 @@ test "Primitives casts" {
         [2]type{ f32, u32 },
         [2]type{ f32, i32 },
         [2]type{ u32, f32 },
-        [2]type{ u32, i32 },
         [2]type{ i32, f32 },
-        [2]type{ i32, u32 },
         [2]type{ f32, f64 },
         [2]type{ f64, f32 },
         [2]type{ f64, u32 },
@@ -60,3 +58,51 @@ test "Primitives casts" {
         try case.expectOutput(T[1], 4, code, "color", &.{ expected, expected, expected, expected });
     }
 }
+
+test "Primitives bitcasts" {
+    const allocator = std.testing.allocator;
+    const types = [_][2]type{
+        [2]type{ u32, i32 },
+        [2]type{ i32, u32 },
+    };
+
+    inline for (types) |T| {
+        const base = case.random(T[0]);
+        const expected = @as(T[1], @bitCast(base));
+
+        const shader = try std.fmt.allocPrint(
+            allocator,
+            \\ [nzsl_version("1.1")]
+            \\ [feature(float64)]
+            \\ module;
+            \\ 
+            \\ struct FragOut
+            \\ {{
+            \\     [location(0)] color: vec4[{s}]
+            \\ }}
+            \\
+            \\ [entry(frag)]
+            \\ fn main() -> FragOut
+            \\ {{
+            \\     let base = {s}({d});
+            \\     let color = {s}(base);
+            \\
+            \\     let output: FragOut;
+            \\     output.color = vec4[{s}](color, color, color, color);
+            \\     return output;
+            \\ }}
+        ,
+            .{
+                @typeName(T[1]),
+                @typeName(T[0]),
+                base,
+                @typeName(T[1]),
+                @typeName(T[1]),
+            },
+        );
+        defer allocator.free(shader);
+        const code = try compileNzsl(allocator, shader);
+        defer allocator.free(code);
+        try case.expectOutput(T[1], 4, code, "color", &.{ expected, expected, expected, expected });
+    }
+}