make api source response optional, implement tests

src/api.rs

@@ -1,10 +1,17 @@
 /// Parse infohash from the source filepath,
-/// decode JSON to array on success, return None if the feed is damaged (incomplete)
-pub fn infohashes(path: &str) -> anyhow::Result<Option<Vec<String>>> {
+/// decode JSON to array on success, return None if the feed file is not reachable
+pub fn get(path: &str) -> Option<Vec<String>> {
     if path.contains("://") {
         todo!("URL sources yet not supported")
     }
-    let s = std::fs::read_to_string(path)?;
-    let r: Option<Vec<String>> = serde_json::from_str(&s).ok();
-    Ok(r)
+    let s = std::fs::read_to_string(path).ok()?; // is updating?
+    let r: Option<Vec<String>> = serde_json::from_str(&s).ok(); // is incomplete?
+    r
+}
+
+#[test]
+fn test() {
+    assert!(get("test/api/0.json").is_none());
+    assert!(get("test/api/1.json").is_some());
+    assert!(get("test/api/2.json").is_none());
 }