added path is a dir check in Feed::open

src/feed.rs

@@ -595,11 +595,19 @@ where
 
 impl Feed<RandomAccessDisk> {
     /// Create a new instance that persists to disk at the location of `dir`.
-    // TODO: Ensure that dir is always a directory.
-    // NOTE: Should we `mkdirp` here?
+    /// If dir was not there, it will be created.
     // NOTE: Should we call these `data.bitfield` / `data.tree`?
     pub async fn open<P: AsRef<Path>>(path: P) -> Result<Self> {
+        if let Err(e) = std::fs::create_dir_all(&path) {
+            return Err(anyhow::Error::msg(format!(
+                "Failed to create directory {} because of: {}",
+                path.as_ref().display(),
+                e
+            )));
+        }
+
         let dir = path.as_ref().to_owned();
+
         let storage = Storage::new_disk(&dir).await?;
         Self::with_storage(storage).await
     }

tests/feed.rs

@@ -298,3 +298,33 @@ async fn audit_bad_data() {
         }
     }
 }
+
+#[async_std::test]
+async fn try_open_missing_dir() {
+    use rand::distributions::Alphanumeric;
+    use rand::{thread_rng, Rng};
+
+    let rand_string: String = thread_rng().sample_iter(&Alphanumeric).take(5).collect();
+    let mut dir = std::env::temp_dir();
+    let path = format!("hypercore_rs_test/nonexistent_paths_test/{}", rand_string);
+    dir.push(path);
+
+    if Feed::open(&dir).await.is_err() {
+        panic!("Opening nonexistent dir at a path should succeed");
+    }
+
+    if let Ok(d) = std::fs::metadata(dir) {
+        if !d.is_dir() {
+            panic!("Opening nonexistent dir at a path must create dir");
+        }
+    } else {
+        panic!("Opening nonexistent dir at a path must create dir");
+    }
+}
+
+#[async_std::test]
+async fn try_open_file_as_dir() {
+    if Feed::open("Cargo.toml").await.is_ok() {
+        panic!("Opening path that points to a file must result in error");
+    }
+}