improve user experience when reading files

[glommer]

It took me a while now to figure out why chisel was returning simply
" stream did not contain valid UTF-8"

The reason is because I had temporary files inside the endpoints
directory, but our test is broken. It tests for the dentry.path(),
which ends up being something like "/endpoints/.temporary.swp".

Instead, it should test or dentry.filename(), which is just the last
part. Also, we can't really accept anything that starts with ".", so
we can simplify the test.

In case we do fail for any other reason, I'm also improving the message
by listing which file failed.

[dekimir]

I fixed the build of this branch as follows:

modified   cli/src/main.rs
@@ -72,7 +72,7 @@ fn dir_to_paths(dir: &Path, paths: &mut Vec<PathBuf>) -> anyhow::Result<()> {
         } else if !dentry
             .file_name()
             .to_str()
-            .map_or(false, |x| x.starts_with("."))
+            .map_or(false, |x| x.starts_with('.'))
         {
             // files with names that can't be converted wtih to_str() or that start with . are
             // ignored
@@ -189,7 +189,7 @@ fn read_to_string<P: AsRef<Path>>(filename: P) -> anyhow::Result<String> {
         let mut s = "".to_string();
         stdin()
             .read_to_string(&mut s)
-            .with_context(|| format!("while reading stdin"))?;
+            .with_context(|| "while reading stdin".to_string())?;
         Ok(s)
     } else {
         fs::read_to_string(filename.as_ref())

I also rebased on main and added a test.

[dekimir]

We should also ignore any file ending in tilde -- those are Emacs backup files.

[penberg]

Hmm, I did an explicit list of files because that's what nom, for example is doing. Of course, I did make the list as complete as npm does.