Merge pull request #2793 from tertsdiepraam/cksum-result-io-error

`cksum`: use `UIoError`

src/uu/cksum/src/cksum.rs

@@ -11,8 +11,7 @@ use std::fs::File;
 use std::io::{self, stdin, BufReader, Read};
 use std::path::Path;
 use uucore::display::Quotable;
-use uucore::error::UResult;
-use uucore::error::USimpleError;
+use uucore::error::{FromIo, UResult};
 use uucore::show;
 use uucore::InvalidEncodingHandling;
 
@@ -81,27 +80,18 @@ fn cksum(fname: &str) -> io::Result<(u32, usize)> {
     let mut crc = 0u32;
     let mut size = 0usize;
 
-    let file;
     let mut rd: Box<dyn Read> = match fname {
         "-" => Box::new(stdin()),
         _ => {
-            let path = &Path::new(fname);
-            if path.is_dir() {
-                return Err(std::io::Error::new(
-                    io::ErrorKind::InvalidInput,
-                    "Is a directory",
-                ));
-            };
-            // Silent the warning as we want to the error message
-            #[allow(clippy::question_mark)]
-            if path.metadata().is_err() {
-                return Err(std::io::Error::new(
-                    io::ErrorKind::NotFound,
-                    "No such file or directory",
-                ));
-            };
-            file = File::open(&path)?;
-            Box::new(BufReader::new(file))
+            let p = Path::new(fname);
+
+            // Directories should not give an error, but should be interpreted
+            // as empty files to match GNU semantics.
+            if p.is_dir() {
+                Box::new(BufReader::new(io::empty())) as Box<dyn Read>
+            } else {
+                Box::new(BufReader::new(File::open(p)?)) as Box<dyn Read>
+            }
         }
     };
 
@@ -136,23 +126,16 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     };
 
     if files.is_empty() {
-        match cksum("-") {
-            Ok((crc, size)) => println!("{} {}", crc, size),
-            Err(err) => {
-                return Err(USimpleError::new(2, format!("{}", err)));
-            }
-        }
+        let (crc, size) = cksum("-")?;
+        println!("{} {}", crc, size);
         return Ok(());
     }
 
     for fname in &files {
-        match cksum(fname.as_ref()) {
+        match cksum(fname.as_ref()).map_err_context(|| format!("{}", fname.maybe_quote())) {
             Ok((crc, size)) => println!("{} {} {}", crc, size, fname),
-            Err(err) => show!(USimpleError::new(
-                2,
-                format!("{}: {}", fname.maybe_quote(), err)
-            )),
-        }
+            Err(err) => show!(err),
+        };
     }
     Ok(())
 }

src/uucore/src/lib/mods/error.rs

@@ -371,7 +371,7 @@ impl UError for UUsageError {
 /// ```
 #[derive(Debug)]
 pub struct UIoError {
-    context: String,
+    context: Option<String>,
     inner: std::io::Error,
 }
 
@@ -379,7 +379,7 @@ impl UIoError {
     #[allow(clippy::new_ret_no_self)]
     pub fn new<S: Into<String>>(kind: std::io::ErrorKind, context: S) -> Box<dyn UError> {
         Box::new(Self {
-            context: context.into(),
+            context: Some(context.into()),
             inner: kind.into(),
         })
     }
@@ -435,7 +435,11 @@ impl Display for UIoError {
             capitalize(&mut message);
             &message
         };
-        write!(f, "{}: {}", self.context, message)
+        if let Some(ctx) = &self.context {
+            write!(f, "{}: {}", ctx, message)
+        } else {
+            write!(f, "{}", message)
+        }
     }
 }
 
@@ -464,7 +468,7 @@ pub trait FromIo<T> {
 impl FromIo<Box<UIoError>> for std::io::Error {
     fn map_err_context(self, context: impl FnOnce() -> String) -> Box<UIoError> {
         Box::new(UIoError {
-            context: (context)(),
+            context: Some((context)()),
             inner: self,
         })
     }
@@ -479,12 +483,28 @@ impl<T> FromIo<UResult<T>> for std::io::Result<T> {
 impl FromIo<Box<UIoError>> for std::io::ErrorKind {
     fn map_err_context(self, context: impl FnOnce() -> String) -> Box<UIoError> {
         Box::new(UIoError {
-            context: (context)(),
+            context: Some((context)()),
             inner: std::io::Error::new(self, ""),
         })
     }
 }
 
+impl From<std::io::Error> for UIoError {
+    fn from(f: std::io::Error) -> UIoError {
+        UIoError {
+            context: None,
+            inner: f,
+        }
+    }
+}
+
+impl From<std::io::Error> for Box<dyn UError> {
+    fn from(f: std::io::Error) -> Box<dyn UError> {
+        let u_error: UIoError = f.into();
+        Box::new(u_error) as Box<dyn UError>
+    }
+}
+
 /// Shorthand to construct [`UIoError`]-instances.
 ///
 /// This macro serves as a convenience call to quickly construct instances of

tests/by-util/test_cksum.rs

@@ -74,9 +74,8 @@ fn test_invalid_file() {
     at.mkdir(folder_name);
     ts.ucmd()
         .arg(folder_name)
-        .fails()
-        .no_stdout()
-        .stderr_contains("cksum: asdf: Is a directory");
+        .succeeds()
+        .stdout_only("4294967295 0 asdf\n");
 }
 
 // Make sure crc is correct for files larger than 32 bytes