feat(fs): add .copy(dest)

README.md

@@ -5,7 +5,7 @@ Provides injectable Filesystem and Network resources to make code more testable.
 #### std::fs alternatives
 
 - [ ] `std::fs::canonicalize` - `path(path).canonicalize()` - Returns the canonical, absolute form of a path with all intermediate components normalized and symbolic links resolved.
-- [ ] `std::fs::copy` - `file(path).copy(target)` - Copies the contents of one file to another. This function will also copy the permission bits of the original file to the destination file.
+- [x] `std::fs::copy` - `file(path).copy(target)` - Copies the contents of one file to another. This function will also copy the permission bits of the original file to the destination file.
 - [x] `std::fs::create_dir` - `dir(path).create()` - Creates a new, empty directory at the provided path
 - [x] `std::fs::create_dir_all` - `dir(path).create_all()` - Recursively create a directory and all of its parent components if they are missing.
 - [ ] `std::fs::hard_link` - `link(path)create()` - Creates a new hard link on the filesystem.

src/fs/file.rs

@@ -41,4 +41,25 @@ impl<'base, 'path> FileHandle<'base, 'path> {
         self.check_error()?;
         std::fs::write(self.as_pathbuf(), contents).map_err(Error::Io)
     }
+
+    /// Copies the contents of a file to another file.
+    ///
+    /// Wrapper for [std::fs::copy]
+    ///
+    /// ```
+    /// # fn try_main() -> kxio::fs::Result<()> {
+    /// let fs = kxio::fs::temp()?;
+    /// let src_path = fs.base().join("foo");
+    /// let dest_path = fs.base().join("bar");
+    /// let src = fs.file(&src_path);
+    /// # fs.file(&dest_path).write("new file contents")?;
+    /// let dest = fs.file(&dest_path);
+    /// src.copy(&dest)?;
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub fn copy(&self, dest: &PathReal<'base, 'path, FileMarker>) -> Result<u64> {
+        self.check_error()?;
+        std::fs::copy(self.as_pathbuf(), dest.as_pathbuf()).map_err(Error::Io)
+    }
 }

tests/fs.rs

@@ -385,3 +385,21 @@ mod path_is_file {
         Ok(())
     }
 }
+mod copy {
+    use super::*;
+    #[test]
+    fn should_copy_a_file() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let src_path = fs.base().join("foo");
+        let src = fs.file(&src_path);
+        src.write("bar").expect("write");
+        let dst_path = fs.base().join("bar");
+        let dst = fs.file(&dst_path);
+        src.copy(&dst).expect("copy");
+        let src_contents = src.reader().expect("reader").to_string();
+        let dst_contents = dst.reader().expect("reader").to_string();
+        assert_eq!(src_contents, dst_contents);
+
+        Ok(())
+    }
+}