Allow creating files with extensions

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
-name          = "mktemp"
-description   = "mktemp files and directories"
-homepage      = "https://docs.rs/mktemp"
+name = "mktemp"
+description = "mktemp files and directories"
+homepage = "https://docs.rs/mktemp"
 documentation = "https://docs.rs/mktemp"
 repository    = "https://github.com/samgiles/rs-mktemp"
 version       = "0.5.1"

src/lib.rs

@@ -39,11 +39,21 @@ fn create_path() -> PathBuf {
     create_path_in(env::temp_dir())
 }
 
+fn create_path_with_ext(extension: &str) -> PathBuf {
+    create_path_with_ext_in(env::temp_dir(), extension)
+}
+
 fn create_path_in(path: PathBuf) -> PathBuf {
+    create_path_with_ext_in(path, "")
+}
+
+fn create_path_with_ext_in(path: PathBuf, extension: &str) -> PathBuf {
     let mut path = path;
     let dir_uuid = Uuid::new_v4();
+    let ext = extension.strip_prefix('.').unwrap_or(extension);
 
     path.push(dir_uuid.simple().to_string());
+    path.set_extension(ext);
     path
 }
 
@@ -88,6 +98,31 @@ impl Temp {
         Ok(temp)
     }
 
+    /// Create a temporary file with a specified extension. `ext` can either be prefixed with '.'
+    /// or not.
+    pub fn new_file_with_extension(extension: &str) -> io::Result<Self> {
+        let path = create_path_with_ext(extension);
+        Self::create_file(&path)?;
+
+        let temp = Temp { path };
+
+        Ok(temp)
+    }
+
+    /// Create a temporary file with a specified extension in an existing directory. `ext` can
+    /// either be prefixed with '.' or not.
+    pub fn new_file_with_extension_in<P: AsRef<Path>>(
+        directory: P,
+        extension: &str,
+    ) -> io::Result<Self> {
+        let path = create_path_with_ext_in(directory.as_ref().to_path_buf(), extension);
+        Self::create_file(&path)?;
+
+        let temp = Temp { path };
+
+        Ok(temp)
+    }
+
     /// Create new uninitialized temporary path, i.e. a file or directory isn't created automatically
     pub fn new_path() -> Self {
         let path = create_path();
@@ -103,6 +138,22 @@ impl Temp {
         Temp { path }
     }
 
+    /// Create new uninitialized temporary path with extension, i.e. a file or directory isn't
+    /// created automatically
+    pub fn new_path_with_extension(extension: &str) -> Self {
+        let path = create_path_with_ext(extension);
+
+        Temp { path }
+    }
+
+    /// Create a new uninitialized temporary path with extension in an existing directory i.e. a file
+    /// or directory isn't created automatically
+    pub fn new_path_with_extension_in<P: AsRef<Path>>(directory: P, extension: &str) -> Self {
+        let path = create_path_with_ext_in(directory.as_ref().to_path_buf(), extension);
+
+        Temp { path }
+    }
+
     /// Return this temporary file or directory as a PathBuf.
     ///
     /// # Examples
@@ -197,9 +248,9 @@ impl Drop for Temp {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use std::fs::File;
     #[cfg(unix)]
     use std::os::unix::fs::MetadataExt;
+    use std::{ffi::OsStr, fs::File};
 
     #[test]
     fn it_should_create_file_in_dir() {
@@ -216,6 +267,36 @@ mod tests {
         }
     }
 
+    #[test]
+    fn it_should_create_file_with_ext() {
+        let temp_file = Temp::new_file_with_extension("json").unwrap();
+        assert_eq!(&temp_file.extension(), &Some(OsStr::new("json")));
+        assert!(fs::metadata(temp_file).unwrap().is_file());
+    }
+
+    #[test]
+    fn it_should_create_file_with_ext_stripping_dot() {
+        let temp_file = Temp::new_file_with_extension(".json").unwrap();
+        assert_eq!(&temp_file.extension(), &Some(OsStr::new("json")));
+        assert!(fs::metadata(temp_file).unwrap().is_file());
+    }
+
+    #[test]
+    fn it_should_create_file_with_ext_in() {
+        let in_dir;
+        {
+            let temp_dir = Temp::new_dir().unwrap();
+
+            in_dir = temp_dir.path.clone();
+
+            {
+                let temp_file = Temp::new_file_with_extension_in(in_dir, "json").unwrap();
+                assert_eq!(&temp_file.extension(), &Some(OsStr::new("json")));
+                assert!(fs::metadata(temp_file).unwrap().is_file());
+            }
+        }
+    }
+
     #[test]
     fn it_should_drop_file_out_of_scope() {
         let path;