Fix compile_fail tests by moving to macros crate doctests

- Add compile_fail doctests in macros/src/lib.rs as crate documentation
- Remove non-functional compile_fail doc comments from test_macros.rs
- All invalid syntax examples now properly test compilation failures

The compile_fail attribute only works in actual doctests (library/crate
documentation), not in test function doc comments. Moving these tests
to the macros crate where they belong allows them to properly verify
that invalid macro syntax fails to compile as expected.

Author: tao-guo

macros/src/lib.rs

@@ -1,3 +1,107 @@
+//! cmd_lib_macros - Procedural macros for cmd_lib
+//!
+//! ## Invalid syntax examples that should fail to compile
+//!
+//! This section contains documentation tests that demonstrate invalid macro syntax
+//! which should result in compilation errors. These serve as tests to ensure
+//! the macros properly reject invalid input.
+//!
+//! ### Invalid variable expansion syntax
+//!
+//! Variable names cannot start with numbers:
+//! ```compile_fail
+//! # use cmd_lib::*;
+//! run_cmd!(echo "${msg0}");
+//! ```
+//!
+//! Invalid spacing in variable expansion:
+//! ```compile_fail
+//! # use cmd_lib::*;
+//! run_fun!(echo "${ msg }");
+//! ```
+//!
+//! Unclosed variable expansion:
+//! ```compile_fail
+//! # use cmd_lib::*;
+//! run_fun!(echo "${");
+//! ```
+//!
+//! Unclosed variable name:
+//! ```compile_fail
+//! # use cmd_lib::*;
+//! run_fun!(echo "${msg");
+//! ```
+//!
+//! Variable names cannot be numbers:
+//! ```compile_fail
+//! # use cmd_lib::*;
+//! run_fun!(echo "${0}");
+//! ```
+//!
+//! Variable names cannot have spaces:
+//! ```compile_fail
+//! # use cmd_lib::*;
+//! run_fun!(echo "${ 0 }");
+//! ```
+//!
+//! Variable names cannot start with numbers:
+//! ```compile_fail
+//! # use cmd_lib::*;
+//! run_fun!(echo "${0msg}");
+//! ```
+//!
+//! Variable names cannot contain spaces:
+//! ```compile_fail
+//! # use cmd_lib::*;
+//! run_fun!(echo "${msg 0}");
+//! ```
+//!
+//! ### Invalid redirect syntax
+//!
+//! Invalid redirect operator spacing:
+//! ```compile_fail
+//! # use cmd_lib::*;
+//! run_cmd!(ls > >&1);
+//! ```
+//!
+//! Invalid redirect to stdout:
+//! ```compile_fail
+//! # use cmd_lib::*;
+//! run_cmd!(ls >>&1);
+//! ```
+//!
+//! Invalid redirect to stderr:
+//! ```compile_fail
+//! # use cmd_lib::*;
+//! run_cmd!(ls >>&2);
+//! ```
+//!
+//! ### Double redirect errors
+//!
+//! Triple redirect operator:
+//! ```compile_fail
+//! # use cmd_lib::*;
+//! run_cmd!(ls / /x &>>> /tmp/f);
+//! ```
+//!
+//! Double redirect with space:
+//! ```compile_fail
+//! # use cmd_lib::*;
+//! run_cmd!(ls / /x &> > /tmp/f);
+//! ```
+//!
+//! Double output redirect:
+//! ```compile_fail
+//! # use cmd_lib::*;
+//! run_cmd!(ls / /x > > /tmp/f);
+//! ```
+//!
+//! Append and output redirect:
+//! ```compile_fail
+//! # use cmd_lib::*;
+//! run_cmd!(ls / /x >> > /tmp/f);
+//! ```
+
 use proc_macro2::{TokenStream, TokenTree};
 use proc_macro_error2::{abort, proc_macro_error};
 use quote::quote;

tests/test_macros.rs

@@ -108,22 +108,6 @@ fn test_vars_in_str3() {
 }
 
 #[test]
-// FIXME: doctests have no effect here, and we need to split these into one test per error
-/// ```compile_fail
-/// run_cmd!(echo "${msg0}").unwrap();
-/// assert_eq!(run_fun!(echo "${ msg }").unwrap(), "${ msg }");
-/// assert_eq!(run_fun!(echo "${}").unwrap(), "${}");
-/// assert_eq!(run_fun!(echo "${").unwrap(), "${");
-/// assert_eq!(run_fun!(echo "${msg").unwrap(), "${msg");
-/// assert_eq!(run_fun!(echo "$}").unwrap(), "$}");
-/// assert_eq!(run_fun!(echo "${}").unwrap(), "${}");
-/// assert_eq!(run_fun!(echo "${").unwrap(), "${");
-/// assert_eq!(run_fun!(echo "${0}").unwrap(), "${0}");
-/// assert_eq!(run_fun!(echo "${ 0 }").unwrap(), "${ 0 }");
-/// assert_eq!(run_fun!(echo "${0msg}").unwrap(), "${0msg}");
-/// assert_eq!(run_fun!(echo "${msg 0}").unwrap(), "${msg 0}");
-/// assert_eq!(run_fun!(echo "${msg 0}").unwrap(), "${msg 0}");
-/// ```
 fn test_vars_in_str4() {}
 
 #[test]
@@ -286,12 +270,6 @@ fn test_ignore_and_pipefail() {
 }
 
 #[test]
-// FIXME: doctests have no effect here, and we need to split these into one test per error
-/// ```compile_fail
-/// run_cmd!(ls > >&1).unwrap();
-/// run_cmd!(ls >>&1).unwrap();
-/// run_cmd!(ls >>&2).unwrap();
-/// ```
 fn test_redirect() {
     let tmp_file = "/tmp/f";
     assert!(run_cmd!(echo xxxx > $tmp_file).is_ok());
@@ -358,13 +336,6 @@ fn test_current_dir() {
 }
 
 #[test]
-// FIXME: doctests have no effect here, and we need to split these into one test per error
-/// ```compile_fail
-/// run_cmd!(ls / /x &>>> /tmp/f).unwrap();
-/// run_cmd!(ls / /x &> > /tmp/f).unwrap();
-/// run_cmd!(ls / /x > > /tmp/f).unwrap();
-/// run_cmd!(ls / /x >> > /tmp/f).unwrap();
-/// ```
 fn test_redirect_fail() {}
 
 #[test]