Fix compile_fail tests using trybuild

The previous approach using doc comments with ```compile_fail didn't
work in regular test functions. Trybuild provides the correct way to
test compilation failures with expected error messages.

Author: tao-guo

Cargo.toml

@@ -30,6 +30,7 @@ rayon = "1.8.0"
 clap = { version = "4", features = ["derive"] }
 byte-unit = "4.0.19"
 tracing-subscriber = { version = "0.3.19", features = ["env-filter"] }
+trybuild = "1.0"
 
 [features]
 build-print = ["dep:build-print"]

tests/compile_fail.rs

@@ -0,0 +1,5 @@
+#[test]
+fn compile_fail_tests() {
+    let t = trybuild::TestCases::new();
+    t.compile_fail("tests/ui/compile_fail.rs");
+}

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]

tests/ui/compile_fail.rs

@@ -0,0 +1,26 @@
+use cmd_lib::*;
+
+fn main() {
+    // Invalid variable expansions
+    run_cmd!(echo "${msg0}").unwrap();
+    run_fun!(echo "${ msg }").unwrap();
+    run_fun!(echo "${}").unwrap();
+    run_fun!(echo "${").unwrap();
+    run_fun!(echo "${msg").unwrap();
+    run_fun!(echo "$}").unwrap();
+    run_fun!(echo "${0}").unwrap();
+    run_fun!(echo "${ 0 }").unwrap();
+    run_fun!(echo "${0msg}").unwrap();
+    run_fun!(echo "${msg 0}").unwrap();
+
+    // Invalid redirect syntax
+    run_cmd!(ls > >&1).unwrap();
+    run_cmd!(ls >> &1).unwrap();
+    run_cmd!(ls >> &2).unwrap();
+
+    // Double redirect errors
+    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();
+}

tests/ui/compile_fail.stderr

@@ -0,0 +1,91 @@
+error: bad substitution: expected '}'
+ --> tests/ui/compile_fail.rs:6:19
+  |
+6 |     run_fun!(echo "${ msg }").unwrap();
+  |                   ^^^^^^^^^^
+
+error: bad substitution: expected '}'
+ --> tests/ui/compile_fail.rs:8:19
+  |
+8 |     run_fun!(echo "${").unwrap();
+  |                   ^^^^
+
+error: bad substitution: expected '}'
+ --> tests/ui/compile_fail.rs:9:19
+  |
+9 |     run_fun!(echo "${msg").unwrap();
+  |                   ^^^^^^^
+
+error: bad substitution: expected '}'
+  --> tests/ui/compile_fail.rs:11:19
+   |
+11 |     run_fun!(echo "${0}").unwrap();
+   |                   ^^^^^^
+
+error: bad substitution: expected '}'
+  --> tests/ui/compile_fail.rs:12:19
+   |
+12 |     run_fun!(echo "${ 0 }").unwrap();
+   |                   ^^^^^^^^
+
+error: bad substitution: expected '}'
+  --> tests/ui/compile_fail.rs:13:19
+   |
+13 |     run_fun!(echo "${0msg}").unwrap();
+   |                   ^^^^^^^^^
+
+error: bad substitution: expected '}'
+  --> tests/ui/compile_fail.rs:14:19
+   |
+14 |     run_fun!(echo "${msg 0}").unwrap();
+   |                   ^^^^^^^^^^
+
+error: wrong double redirection format
+  --> tests/ui/compile_fail.rs:17:19
+   |
+17 |     run_cmd!(ls > >&1).unwrap();
+   |                   ^
+
+error: raw fd not allowed for append redirection
+  --> tests/ui/compile_fail.rs:18:19
+   |
+18 |     run_cmd!(ls >>&1).unwrap();
+   |                   ^
+
+error: raw fd not allowed for append redirection
+  --> tests/ui/compile_fail.rs:19:19
+   |
+19 |     run_cmd!(ls >>&2).unwrap();
+   |                   ^
+
+error: wrong double redirection format
+  --> tests/ui/compile_fail.rs:22:25
+   |
+22 |     run_cmd!(ls / /x &>>> /tmp/f).unwrap();
+   |                         ^
+
+error: wrong double redirection format
+  --> tests/ui/compile_fail.rs:23:25
+   |
+23 |     run_cmd!(ls / /x &> > /tmp/f).unwrap();
+   |                         ^
+
+error: wrong double redirection format
+  --> tests/ui/compile_fail.rs:24:24
+   |
+24 |     run_cmd!(ls / /x > > /tmp/f).unwrap();
+   |                        ^
+
+error: wrong double redirection format
+  --> tests/ui/compile_fail.rs:25:25
+   |
+25 |     run_cmd!(ls / /x >> > /tmp/f).unwrap();
+   |                         ^
+
+error[E0425]: cannot find value `msg0` in this scope
+ --> tests/ui/compile_fail.rs:5:5
+  |
+5 |     run_cmd!(echo "${msg0}").unwrap();
+  |     ^^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope
+  |
+  = note: this error originates in the macro `run_cmd` (in Nightly builds, run with -Z macro-backtrace for more info)