Added initialization failure.

src/morethantext/cache.rs

@@ -184,15 +184,21 @@ impl Entry {
 struct Cache;
 
 impl Cache {
-    async fn new<P>(dir: P) -> Self
+    async fn new<P>(dir: P) -> Result<Self, DBError>
     where
         P: Into<PathBuf>,
     {
         let pathbuf = dir.into();
         let entry = pathbuf.as_path().join(ENTRY);
         let store = DataType::new("store").unwrap();
-        Entry::new(entry, store).await.unwrap();
-        Self {}
+        match Entry::new(entry, store).await {
+            Ok(_) => Ok(Self {}),
+            Err(err) => {
+                let mut error = DBError::new("initialization failure");
+                error.add_source(err);
+                Err(error)
+            }
+        }
     }
 }
 
@@ -580,12 +586,13 @@ mod entry {
 #[cfg(test)]
 mod cache {
     use super::*;
+    use std::error::Error;
     use tempfile::tempdir;
 
     #[async_std::test]
     async fn create() {
         let dir = tempdir().unwrap();
-        Cache::new(dir.path().to_str().unwrap()).await;
+        Cache::new(dir.path().to_str().unwrap()).await.unwrap();
         let epoint = dir.path().join(ENTRY);
         assert!(
             epoint.is_file(),
@@ -598,4 +605,25 @@ mod cache {
             Vec::<String>::new()
         );
     }
+
+    #[async_std::test]
+    async fn entry_failure() {
+        let dir = tempdir().unwrap();
+        let path = dir.path().join("bad").join("path");
+        match Cache::new(path).await {
+            Ok(_) => assert!(false, "Should have produced an error."),
+            Err(err) => {
+                assert_eq!(err.to_string(), "initialization failure");
+                assert!(err.source().is_some(), "Error should have a source.");
+                assert!(
+                    err.source()
+                        .unwrap()
+                        .to_string()
+                        .contains("failed to write"),
+                    "Source Error Message: {}",
+                    err.source().unwrap().to_string()
+                );
+            }
+        }
+    }
 }