Make File generic over Format and FileExtensions

4 files changed, 66 insertions, 36 deletions

diff --git a/src/file/mod.rs b/src/file/mod.rs
index 2b15a1a..8d5b538 100644
--- a/src/file/mod.rs
+++ b/src/file/mod.rs
@@ -1,36 +1,43 @@
+pub mod extension;
 mod format;
 pub mod source;
-pub mod extension;
 
+use std::fmt::Debug;
 use std::path::{Path, PathBuf};
 
 use crate::error::*;
 use crate::map::Map;
 use crate::source::Source;
 use crate::value::Value;
+use crate::Format;
 
 pub use self::format::FileFormat;
 use self::source::FileSource;
 
+pub use self::extension::FileExtensions;
 pub use self::source::file::FileSourceFile;
 pub use self::source::string::FileSourceString;
 
 #[derive(Clone, Debug)]
-pub struct File<T>
+pub struct File<T, F>
 where
-    T: FileSource,
+    F: Format + FileExtensions,
+    T: FileSource<F>,
 {
     source: T,
 
     /// Format of file (which dictates what driver to use).
-    format: Option<FileFormat>,
+    format: Option<F>,
 
     /// A required File will error if it cannot be found
     required: bool,
 }
 
-impl File<source::string::FileSourceString> {
-    pub fn from_str(s: &str, format: FileFormat) -> Self {
+impl<F> File<source::string::FileSourceString, F>
+where
+    F: Format + FileExtensions + 'static,
+{
+    pub fn from_str(s: &str, format: F) -> Self {
         File {
             format: Some(format),
             required: true,
@@ -39,15 +46,20 @@ impl File<source::string::FileSourceString> {
     }
 }
 
-impl File<source::file::FileSourceFile> {
-    pub fn new(name: &str, format: FileFormat) -> Self {
+impl<F> File<source::file::FileSourceFile, F>
+where
+    F: Format + FileExtensions + 'static,
+{
+    pub fn new(name: &str, format: F) -> Self {
         File {
             format: Some(format),
             required: true,
             source: source::file::FileSourceFile::new(name.into()),
         }
     }
+}
 
+impl File<source::file::FileSourceFile, FileFormat> {
     /// Given the basename of a file, will attempt to locate a file by setting its
     /// extension to a registered format.
     pub fn with_name(name: &str) -> Self {
@@ -59,7 +71,7 @@ impl File<source::file::FileSourceFile> {
     }
 }
 
-impl<'a> From<&'a Path> for File<source::file::FileSourceFile> {
+impl<'a> From<&'a Path> for File<source::file::FileSourceFile, FileFormat> {
     fn from(path: &'a Path) -> Self {
         File {
             format: None,
@@ -69,7 +81,7 @@ impl<'a> From<&'a Path> for File<source::file::FileSourceFile> {
     }
 }
 
-impl From<PathBuf> for File<source::file::FileSourceFile> {
+impl From<PathBuf> for File<source::file::FileSourceFile, FileFormat> {
     fn from(path: PathBuf) -> Self {
         File {
             format: None,
@@ -79,8 +91,12 @@ impl From<PathBuf> for File<source::file::FileSourceFile> {
     }
 }
 
-impl<T: FileSource> File<T> {
-    pub fn format(mut self, format: FileFormat) -> Self {
+impl<T, F> File<T, F>
+where
+    F: Format + FileExtensions + 'static,
+    T: FileSource<F>,
+{
+    pub fn format(mut self, format: F) -> Self {
         self.format = Some(format);
         self
     }
@@ -91,10 +107,10 @@ impl<T: FileSource> File<T> {
     }
 }
 
-impl<T: FileSource> Source for File<T>
+impl<T, F> Source for File<T, F>
 where
-    T: 'static,
-    T: Sync + Send,
+    F: Format + FileExtensions + Debug + Clone + Send + Sync + 'static,
+    T: Sync + Send + FileSource<F> + 'static,
 {
     fn clone_into_box(&self) -> Box<dyn Source + Send + Sync> {
         Box::new((*self).clone())
@@ -104,7 +120,7 @@ where
         // Coerce the file contents to a string
         let (uri, contents, format) = match self
             .source
-            .resolve(self.format)
+            .resolve(self.format.clone())
             .map_err(|err| ConfigError::Foreign(err))
         {
             Ok((uri, contents, format)) => (uri, contents, format),
diff --git a/src/file/source/file.rs b/src/file/source/file.rs
index 75634dd..0feb447 100644
--- a/src/file/source/file.rs
+++ b/src/file/source/file.rs
@@ -6,7 +6,8 @@ use std::iter::Iterator;
 use std::path::{Path, PathBuf};
 
 use crate::file::format::ALL_EXTENSIONS;
-use crate::file::{FileFormat, FileSource};
+use crate::file::{FileExtensions, FileSource};
+use crate::Format;
 
 /// Describes a file sourced from a file
 #[derive(Clone, Debug)]
@@ -20,15 +21,18 @@ impl FileSourceFile {
         FileSourceFile { name }
     }
 
-    fn find_file(
+    fn find_file<F>(
         &self,
-        format_hint: Option<FileFormat>,
-    ) -> Result<(PathBuf, FileFormat), Box<dyn Error + Send + Sync>> {
+        format_hint: Option<F>,
+    ) -> Result<(PathBuf, Box<dyn Format>), Box<dyn Error + Send + Sync>>
+    where
+        F: FileExtensions + Format + 'static,
+    {
         // First check for an _exact_ match
         let mut filename = env::current_dir()?.as_path().join(self.name.clone());
         if filename.is_file() {
             return match format_hint {
-                Some(format) => Ok((filename, format)),
+                Some(format) => Ok((filename, Box::new(format))),
                 None => {
                     for (format, extensions) in ALL_EXTENSIONS.iter() {
                         if extensions.contains(
@@ -38,7 +42,7 @@ impl FileSourceFile {
                                 .to_string_lossy()
                                 .as_ref(),
                         ) {
-                            return Ok((filename, *format));
+                            return Ok((filename, Box::new(*format)));
                         }
                     }
 
@@ -59,7 +63,7 @@ impl FileSourceFile {
                     filename.set_extension(ext);
 
                     if filename.is_file() {
-                        return Ok((filename, format));
+                        return Ok((filename, Box::new(format)));
                     }
                 }
             }
@@ -70,7 +74,7 @@ impl FileSourceFile {
                         filename.set_extension(ext);
 
                         if filename.is_file() {
-                            return Ok((filename, *format));
+                            return Ok((filename, Box::new(*format)));
                         }
                     }
                 }
@@ -87,11 +91,14 @@ impl FileSourceFile {
     }
 }
 
-impl FileSource for FileSourceFile {
+impl<F> FileSource<F> for FileSourceFile
+where
+    F: Format + FileExtensions + 'static,
+{
     fn resolve(
         &self,
-        format_hint: Option<FileFormat>,
-    ) -> Result<(Option<String>, String, FileFormat), Box<dyn Error + Send + Sync>> {
+        format_hint: Option<F>,
+    ) -> Result<(Option<String>, String, Box<dyn Format>), Box<dyn Error + Send + Sync>> {
         // Find file
         let (filename, format) = self.find_file(format_hint)?;
 
diff --git a/src/file/source/mod.rs b/src/file/source/mod.rs
index 3b42a55..4a8877b 100644
--- a/src/file/source/mod.rs
+++ b/src/file/source/mod.rs
@@ -4,12 +4,15 @@ pub mod string;
 use std::error::Error;
 use std::fmt::Debug;
 
-use crate::file::FileFormat;
+use crate::{file::FileExtensions, Format};
 
 /// Describes where the file is sourced
-pub trait FileSource: Debug + Clone {
+pub trait FileSource<T>: Debug + Clone
+where
+    T: Format + FileExtensions,
+{
     fn resolve(
         &self,
-        format_hint: Option<FileFormat>,
-    ) -> Result<(Option<String>, String, FileFormat), Box<dyn Error + Send + Sync>>;
+        format_hint: Option<T>,
+    ) -> Result<(Option<String>, String, Box<dyn Format>), Box<dyn Error + Send + Sync>>;
 }
diff --git a/src/file/source/string.rs b/src/file/source/string.rs
index 2fede45..9bec751 100644
--- a/src/file/source/string.rs
+++ b/src/file/source/string.rs
@@ -1,6 +1,7 @@
 use std::error::Error;
 
-use crate::file::{FileFormat, FileSource};
+use crate::file::{FileExtensions, FileSource};
+use crate::Format;
 
 /// Describes a file sourced from a string
 #[derive(Clone, Debug)]
@@ -12,15 +13,18 @@ impl<'a> From<&'a str> for FileSourceString {
     }
 }
 
-impl FileSource for FileSourceString {
+impl<F> FileSource<F> for FileSourceString
+where
+    F: Format + FileExtensions + 'static,
+{
     fn resolve(
         &self,
-        format_hint: Option<FileFormat>,
-    ) -> Result<(Option<String>, String, FileFormat), Box<dyn Error + Send + Sync>> {
+        format_hint: Option<F>,
+    ) -> Result<(Option<String>, String, Box<dyn Format>), Box<dyn Error + Send + Sync>> {
         Ok((
             None,
             self.0.clone(),
-            format_hint.expect("from_str requires a set file format"),
+            Box::new(format_hint.expect("from_str requires a set file format")),
         ))
     }
 }