Provide impl TryFrom for OS strings and paths on Windows

Author: allenap

.github/workflows/build.yml

@@ -8,16 +8,25 @@ on:
 jobs:
   test:
     name: Test
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest]
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@stable
       # Make sure we have all the target shells installed.
-      - run: sudo apt-get install -y bash dash fish zsh
+      - name: Install shells (Ubuntu)
+        if: runner.os == 'Linux'
+        run: sudo apt-get install -y bash dash fish zsh
+      - name: Install shells (Windows)
+        if: runner.os == 'Windows'
+        run: choco install git -y --no-progress # `git` includes `bash`.
       # Record shell versions. Almost unbelievably, it's not possible to get the
       # version of Dash from `dash` itself, so we skip it here. Since `sh` might
       # be `dash`, we also do not try to get its version.
-      - name: Shell versions
+      - name: Shell versions (Ubuntu)
+        if: runner.os == 'Linux'
         run: |
           for shell in sh dash; do
             for path in $(type -ap "$shell"); do
@@ -30,6 +39,17 @@ jobs:
               printf "%10s @ %-30q: %s\n" "$shell" "$path" "$version"
             done
           done
+      - name: Shell versions (Windows)
+        if: runner.os == 'Windows'
+        shell: bash
+        run: |
+          for shell in bash; do
+            if command -v "$shell" &> /dev/null; then
+              path=$(command -v "$shell")
+              version=$("$shell" --version | head -n 1)
+              printf "%10s @ %-30s: %s\n" "$shell" "$path" "$version"
+            fi
+          done
       # Test in debug mode first.
       - run: cargo test
       # Test in release mode too, to defend against, for example, use of

README.md

@@ -49,7 +49,7 @@ It can take as input many different string and byte string types:
 - [`&str`] and [`String`]
 - [`&bstr::BStr`][`bstr::BStr`] and [`bstr::BString`]
 - [`&[u8]`][`slice`] and [`Vec<u8>`]
-- [`&OsStr`][`OsStr`] and [`OsString`] (on UNIX)
+- [`&OsStr`][`OsStr`] and [`OsString`]
 - [`&Path`][`Path`] and [`PathBuf`]
 
 and produce output as (or push into) the following types:

src/lib.rs

@@ -36,9 +36,6 @@
     doc = include_str!("../README.md")
 )]
 
-use std::ffi::{OsStr, OsString};
-use std::path::{Path, PathBuf};
-
 mod ascii;
 mod bash;
 mod fish;
@@ -176,22 +173,6 @@ impl<'a> From<&'a String> for Quotable<'a> {
     }
 }
 
-#[cfg(unix)]
-impl<'a> From<&'a OsStr> for Quotable<'a> {
-    fn from(source: &'a OsStr) -> Quotable<'a> {
-        use std::os::unix::ffi::OsStrExt;
-        source.as_bytes().into()
-    }
-}
-
-#[cfg(unix)]
-impl<'a> From<&'a OsString> for Quotable<'a> {
-    fn from(source: &'a OsString) -> Quotable<'a> {
-        use std::os::unix::ffi::OsStrExt;
-        source.as_bytes().into()
-    }
-}
-
 #[cfg(feature = "bstr")]
 impl<'a> From<&'a bstr::BStr> for Quotable<'a> {
     fn from(source: &'a bstr::BStr) -> Quotable<'a> {
@@ -208,16 +189,99 @@ impl<'a> From<&'a bstr::BString> for Quotable<'a> {
     }
 }
 
+// ----------------------------------------------------------------------------
+
+/// Unix-specific support.
 #[cfg(unix)]
-impl<'a> From<&'a Path> for Quotable<'a> {
-    fn from(source: &'a Path) -> Quotable<'a> {
-        source.as_os_str().into()
+mod platform {
+    use std::ffi::{OsStr, OsString};
+    use std::path::{Path, PathBuf};
+
+    use super::Quotable;
+
+    impl<'a> From<&'a OsStr> for Quotable<'a> {
+        fn from(source: &'a OsStr) -> Quotable<'a> {
+            use std::os::unix::ffi::OsStrExt;
+            source.as_bytes().into()
+        }
+    }
+
+    impl<'a> From<&'a OsString> for Quotable<'a> {
+        fn from(source: &'a OsString) -> Quotable<'a> {
+            use std::os::unix::ffi::OsStrExt;
+            source.as_bytes().into()
+        }
+    }
+
+    impl<'a> From<&'a Path> for Quotable<'a> {
+        fn from(source: &'a Path) -> Quotable<'a> {
+            source.as_os_str().into()
+        }
+    }
+
+    impl<'a> From<&'a PathBuf> for Quotable<'a> {
+        fn from(source: &'a PathBuf) -> Quotable<'a> {
+            source.as_os_str().into()
+        }
     }
 }
 
-#[cfg(unix)]
-impl<'a> From<&'a PathBuf> for Quotable<'a> {
-    fn from(source: &'a PathBuf) -> Quotable<'a> {
-        source.as_os_str().into()
+// ----------------------------------------------------------------------------
+
+#[cfg(windows)]
+pub use platform::UnicodeError;
+
+/// Windows-specific support.
+#[cfg(windows)]
+mod platform {
+    use std::ffi::{OsStr, OsString};
+    use std::path::{Path, PathBuf};
+
+    use super::Quotable;
+
+    /// Error when converting an [`OsStr`]/[`OsString`] that contains invalid
+    /// Unicode, e.g. unpaired UTF-16 surrogates on Windows.
+    #[derive(Debug, Clone)]
+    #[non_exhaustive]
+    pub struct UnicodeError {}
+
+    impl std::error::Error for UnicodeError {}
+
+    impl std::fmt::Display for UnicodeError {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            write!(f, "invalid Unicode (unpaired UTF-16 surrogates)")
+        }
+    }
+
+    impl<'a> TryFrom<&'a OsStr> for Quotable<'a> {
+        type Error = UnicodeError;
+
+        fn try_from(source: &'a OsStr) -> Result<Self, Self::Error> {
+            source.to_str().map(Quotable::Text).ok_or(UnicodeError {})
+        }
+    }
+
+    impl<'a> TryFrom<&'a OsString> for Quotable<'a> {
+        type Error = UnicodeError;
+
+        fn try_from(source: &'a OsString) -> Result<Self, Self::Error> {
+            source.as_os_str().try_into()
+        }
+    }
+
+    impl<'a> TryFrom<&'a Path> for Quotable<'a> {
+        type Error = UnicodeError;
+
+        fn try_from(source: &'a Path) -> Result<Self, Self::Error> {
+            source.as_os_str().try_into()
+        }
+    }
+
+    impl<'a> TryFrom<&'a PathBuf> for Quotable<'a> {
+        type Error = UnicodeError;
+
+        fn try_from(source: &'a PathBuf) -> Result<Self, Self::Error> {
+            source.as_os_str().try_into()
+        }
     }
 }