[storage] Construct FileStorage with filename and create a file #53 (#58

)

* Update file_storage.rs

* Update file_storage.rs

* Update file_storage.rs

* Update file_storage.rs

src/storage/file_storage.rs

@@ -1,13 +1,49 @@
+use std::fs::{File, OpenOptions};
+
 #[allow(dead_code)]
-#[derive(Default)]
-pub(crate) struct FileStorage {}
+pub(crate) struct FileStorage {
+    filename: String,
+    file: File,
+}
+
+impl From<&str> for FileStorage {
+    fn from(filename: &str) -> Self {
+        FileStorage::from(filename.to_string())
+    }
+}
+
+impl From<String> for FileStorage {
+    fn from(filename: String) -> Self {
+        FileStorage {
+            file: OpenOptions::new()
+                .write(true)
+                .create(true)
+                .read(true)
+                .open(&filename)
+                .unwrap(),
+            filename,
+        }
+    }
+}
 
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::test_utilities::test_file::TestFile;
+    use std::path::Path;
+
+    #[test]
+    fn create_new_file() {
+        let test_file = TestFile::from("./file_storage_test01.agdb");
+        let _storage = FileStorage::from(test_file.file_name().as_str());
+
+        assert!(Path::new(test_file.file_name()).exists());
+    }
 
     #[test]
-    fn file_storage() {
-        let _storage = FileStorage::default();
+    fn open_existing_file() {
+        let test_file = TestFile::from("./file_storage_test02.agdb");
+        File::create(test_file.file_name()).unwrap();
+        let _storage = FileStorage::from(test_file.file_name().clone());
     }
 }