2 files changed, 70 insertions, 29 deletions

diff --git a/src/configuration.rs b/src/configuration.rs
index a09d780..333a27f 100644
--- a/src/configuration.rs
+++ b/src/configuration.rs
@@ -1,4 +1,5 @@
 use std::env;
+use std::io::{Error, ErrorKind, Result};
 use std::path::PathBuf;
 
 pub struct Configuration {
@@ -7,31 +8,70 @@ pub struct Configuration {
 }
 
 impl Configuration {
+    pub fn new() -> Result<Self> {
+        let output_directory =
+            Configuration::directory("PAGE_OUTPUT_DIRECTORY", "XDG_CACHE_HOME", ".cache", "page")?;
 
-    pub fn new() -> Self  {
-        let output_directory = Configuration::directory(
-            "PAGE_OUTPUT_DIRECTORY",
-            "XDG_CACHE_HOME",
-            ".cache",
-            "page"
-        );
-
-        Configuration {
-            output_directory,
-        }
+        Ok(Configuration { output_directory })
     }
 
-    fn directory(user_override: &str, default_value: &str, home_fallback: &str, path: &str) -> PathBuf {
+    fn directory(
+        user_override: &str,
+        default_value: &str,
+        home_fallback: &str,
+        path: &str,
+    ) -> Result<PathBuf> {
         match env::var(user_override) {
-            Ok(directory) => PathBuf::from(directory),
+            Ok(directory) => Ok(PathBuf::from(directory).join(path)),
             Err(_) => match env::var(default_value) {
-                Ok(directory) => PathBuf::from(directory),
+                Ok(directory) => Ok(PathBuf::from(directory).join(path)),
                 Err(_) => match env::var("HOME") {
-                    Ok(directory) => PathBuf::from(directory).join(home_fallback),
-                    Err(_) => panic!("Could not find required directory, {} or {} should be set and readable.", user_override, default_value),
+                    Ok(directory) => Ok(PathBuf::from(directory).join(home_fallback).join(path)),
+                    Err(_) => Err(Error::new(
+                        ErrorKind::NotFound,
+                        format!(
+                            "Could not find required directory, {user_override} or {default_value} should be set and readable"
+                        ),
+                    )),
                 },
             },
-        }.join(path)
+        }
     }
 }
 
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::env;
+
+    use test_utilities::*;
+
+    #[test]
+    fn test_sets_correct_configuration_directories() {
+        let default_configuration = Configuration::new().unwrap();
+
+        let test_dir = setup_test_dir();
+
+        // SAFETY: Run only in single-threaded mode
+        unsafe {
+            env::set_var("PAGE_OUTPUT_DIRECTORY", test_dir.join("output"));
+        }
+        let override_configuration = Configuration::new().unwrap();
+
+        // Ensure our overrides were applied
+
+        assert_eq!(
+            override_configuration.output_directory,
+            test_dir.join("output/page")
+        );
+
+        // Ensure all the defaults are different from defaults
+
+        assert_ne!(
+            default_configuration.output_directory,
+            override_configuration.output_directory
+        );
+
+        cleanup_test_dir(&test_dir);
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index 9dd296a..d0ed57c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,4 @@
+mod configuration;
 mod file_finder;
 mod file_handler;
 
@@ -5,10 +6,12 @@ use std::env::current_dir;
 use std::fs::{create_dir_all, remove_dir_all};
 use std::io::{Error, ErrorKind, Result};
 
-use crate::file_finder::find_files;
-use crate::file_handler::FileHandler;
+use configuration::Configuration;
+use file_finder::find_files;
+use file_handler::FileHandler;
 
 fn main() -> Result<()> {
+    let configuration = Configuration::new()?;
     let source = current_dir()?;
     let source_name = source
         .file_name()
@@ -19,16 +22,14 @@ fn main() -> Result<()> {
             )
         })?
         .to_string_lossy();
-    let parent = source.parent().ok_or_else(|| {
-        Error::new(
-            ErrorKind::InvalidData,
-            "Current directory parent was not readable.",
-        )
-    })?;
-    let gemini_destination_name = format!("{source_name}_gemini");
-    let gemini_destination = parent.join(gemini_destination_name);
-    let html_destination_name = format!("{source_name}_html");
-    let html_destination = parent.join(html_destination_name);
+    let gemini_destination = configuration
+        .output_directory
+        .join(format!("{source_name}"))
+        .join("gemini");
+    let html_destination = configuration
+        .output_directory
+        .join(format!("{source_name}"))
+        .join("html");
 
     // Step 1. Identify the files
     let files = find_files(&source);