Merge pull request #365 from dtolnay/ensuretype

Add tests for `ensure!` with non-bool argument

tests/test_macros.rs

@@ -3,6 +3,7 @@
     clippy::eq_op,
     clippy::incompatible_msrv, // https://github.com/rust-lang/rust-clippy/issues/12257
     clippy::items_after_statements,
+    clippy::match_single_binding,
     clippy::needless_pass_by_value,
     clippy::shadow_unrelated,
     clippy::wildcard_imports
@@ -11,7 +12,7 @@
 mod common;
 
 use self::common::*;
-use anyhow::{anyhow, ensure};
+use anyhow::{anyhow, ensure, Result};
 use std::cell::Cell;
 use std::future;
 
@@ -53,6 +54,22 @@ fn test_ensure() {
     );
 }
 
+#[test]
+fn test_ensure_nonbool() {
+    struct Struct {
+        condition: bool,
+    }
+
+    fn f(s: &Struct) -> Result<()> {
+        match s {
+            Struct { condition } => ensure!(condition), // &bool
+        }
+        Ok(())
+    }
+
+    f(&Struct { condition: true }).unwrap();
+}
+
 #[test]
 fn test_temporaries() {
     fn require_send_sync(_: impl Send + Sync) {}

tests/ui/ensure-nonbool.rs

@@ -0,0 +1,13 @@
+use anyhow::{ensure, Result};
+
+fn main() -> Result<()> {
+    ensure!("...");
+
+    struct Struct(bool);
+    let mut s = Struct(true);
+    match &mut s {
+        Struct(cond) => ensure!(cond),
+    }
+
+    Ok(())
+}

tests/ui/ensure-nonbool.stderr

@@ -0,0 +1,15 @@
+error[E0600]: cannot apply unary operator `!` to type `&'static str`
+ --> tests/ui/ensure-nonbool.rs:4:5
+  |
+4 |     ensure!("...");
+  |     ^^^^^^^^^^^^^^ cannot apply unary operator `!`
+  |
+  = note: this error originates in the macro `$crate::__fallback_ensure` which comes from the expansion of the macro `ensure` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0600]: cannot apply unary operator `!` to type `&mut bool`
+ --> tests/ui/ensure-nonbool.rs:9:25
+  |
+9 |         Struct(cond) => ensure!(cond),
+  |                         ^^^^^^^^^^^^^ cannot apply unary operator `!`
+  |
+  = note: this error originates in the macro `$crate::__fallback_ensure` which comes from the expansion of the macro `ensure` (in Nightly builds, run with -Z macro-backtrace for more info)