♻️ Major code restructuring

src/config/file.rs

@@ -0,0 +1,89 @@
+mod source;
+mod toml;
+
+use crate::config::error::*;
+use crate::config::source::Source;
+use crate::config::value::Value;
+
+use std::collections::HashMap;
+use std::path::{Path, PathBuf};
+
+use self::source::FileSource;
+
+#[derive(Clone, Debug)]
+pub struct File<T>
+where
+    T: FileSource,
+{
+    source: T,
+    /// A required File will error if it cannot be found.
+    required: bool,
+}
+
+impl File<source::FileSourceFile> {
+    /// 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 {
+        File {
+            source: source::FileSourceFile::new(name.into()),
+            required: true,
+        }
+    }
+}
+
+impl<'a> From<&'a Path> for File<source::FileSourceFile> {
+    fn from(path: &'a Path) -> Self {
+        File {
+            source: source::FileSourceFile::new(path.to_path_buf()),
+            required: true,
+        }
+    }
+}
+
+impl From<PathBuf> for File<source::FileSourceFile> {
+    fn from(path: PathBuf) -> Self {
+        File {
+            source: source::FileSourceFile::new(path),
+            required: true,
+        }
+    }
+}
+
+impl<T: FileSource> File<T> {
+    pub fn required(mut self, required: bool) -> Self {
+        self.required = required;
+        self
+    }
+}
+
+impl<T: FileSource> Source for File<T>
+where
+    T: 'static,
+    T: Sync + Send,
+{
+    fn clone_into_box(&self) -> Box<dyn Source + Send + Sync> {
+        Box::new((*self).clone())
+    }
+
+    fn collect(&self) -> Result<HashMap<String, Value>> {
+        // Coerce the file contents to a string.
+        let (uri, contents) = match self
+            .source
+            .resolve()
+            .map_err(|err| ConfigError::Foreign(err))
+        {
+            Ok((uri, contents)) => (uri, contents),
+
+            Err(error) => {
+                if !self.required {
+                    return Ok(HashMap::new());
+                }
+
+                return Err(error);
+            }
+        };
+
+        // Parse the string using the given format.
+        toml::parse(uri.as_ref(), &contents).map_err(|cause| ConfigError::FileParse { uri, cause })
+    }
+}