Added tests.

2 files changed, 37 insertions, 0 deletions

diff --git a/test/stage1/behavior.zig b/test/stage1/behavior.zig
index 61b0c1aa56..a420fd6886 100644
--- a/test/stage1/behavior.zig
+++ b/test/stage1/behavior.zig
@@ -40,6 +40,7 @@ comptime {
     _ = @import("behavior/bugs/3384.zig");
     _ = @import("behavior/bugs/3586.zig");
     _ = @import("behavior/bugs/3742.zig");
+    _ = @import("behavior/bugs/4328.zig");
     _ = @import("behavior/bugs/4560.zig");
     _ = @import("behavior/bugs/4769_a.zig");
     _ = @import("behavior/bugs/4769_b.zig");
diff --git a/test/stage1/behavior/bugs/4328.zig b/test/stage1/behavior/bugs/4328.zig
new file mode 100644
index 0000000000..631c213df1
--- /dev/null
+++ b/test/stage1/behavior/bugs/4328.zig
@@ -0,0 +1,36 @@
+const expectEqual = @import("std").testing.expectEqual;
+
+const FILE = extern struct { dummy_field: u8, };
+extern fn printf([*c]const u8, ...) c_int;
+extern fn fputs([*c]const u8, noalias [*c]FILE) c_int;
+extern fn ftell([*c]FILE) c_long;
+
+test "Extern function call in @TypeOf" {
+    const Test = struct {
+        fn test_fn(a: var, b: var) @TypeOf(printf("%d %s\n", a, b)) {
+            return 0;
+        }
+
+        fn doTheTest() void {
+            expectEqual(c_int, @TypeOf(test_fn(0, 42)));
+        }
+    };
+
+    Test.doTheTest();
+    comptime Test.doTheTest();
+}
+
+test "Peer resolution of extern function calls in @TypeOf" {
+    const Test = struct {
+        fn test_fn() @TypeOf(ftell(null), fputs(null, null)) {
+            return 0;
+        }
+
+        fn doTheTest() void {
+            expectEqual(c_long, @TypeOf(test_fn()));
+        }
+    };
+
+    Test.doTheTest();
+    comptime Test.doTheTest();
+}