macros: add build tests for #[tokio::main] and #[tokio::test] (#1591)

build-tests/tests/fail/macros_invalid_input.rs

@@ -0,0 +1,28 @@
+use build_tests::tokio;
+
+#[tokio::main]
+fn main_is_not_async() {}
+
+#[tokio::main]
+async fn main_fn_has_args(_x: u8) {}
+
+#[tokio::main(foo)]
+async fn main_attr_has_unknown_args() {}
+
+#[tokio::main(multi_thread::bar)]
+async fn main_attr_has_path_args() {}
+
+#[tokio::test]
+fn test_is_not_async() {}
+
+#[tokio::test]
+async fn test_fn_has_args(_x: u8) {}
+
+#[tokio::test(foo)]
+async fn test_attr_has_args() {}
+
+#[tokio::test]
+#[test]
+async fn test_has_second_test_attr() {}
+
+fn main() {}

build-tests/tests/fail/macros_invalid_input.stderr

@@ -0,0 +1,47 @@
+error: the async keyword is missing from the function declaration
+ --> $DIR/macros_invalid_input.rs:4:1
+  |
+4 | fn main_is_not_async() {}
+  | ^^
+
+error: the main function cannot accept arguments
+ --> $DIR/macros_invalid_input.rs:7:27
+  |
+7 | async fn main_fn_has_args(_x: u8) {}
+  |                           ^^^^^^
+
+error: Unknown attribute foo is specified
+ --> $DIR/macros_invalid_input.rs:9:15
+  |
+9 | #[tokio::main(foo)]
+  |               ^^^
+
+error: Must have specified ident
+  --> $DIR/macros_invalid_input.rs:12:15
+   |
+12 | #[tokio::main(multi_thread::bar)]
+   |               ^^^^^^^^^^^^^^^^^
+
+error: the async keyword is missing from the function declaration
+  --> $DIR/macros_invalid_input.rs:16:1
+   |
+16 | fn test_is_not_async() {}
+   | ^^
+
+error: the test function cannot accept arguments
+  --> $DIR/macros_invalid_input.rs:19:27
+   |
+19 | async fn test_fn_has_args(_x: u8) {}
+   |                           ^^^^^^
+
+error: unexpected token
+  --> $DIR/macros_invalid_input.rs:21:15
+   |
+21 | #[tokio::test(foo)]
+   |               ^^^
+
+error: second test attribute is supplied
+  --> $DIR/macros_invalid_input.rs:25:1
+   |
+25 | #[test]
+   | ^^^^^^^