Replace unwraps with more descriptive expects

src/main.rs

@@ -33,13 +33,12 @@ mod catalogs {
 }
 
 // TODO: use clap for proper CLI
-// TODO: replace unwraps with descriptive expects
 
 const MAX_RETRIES: u8 = 10;
 
 lazy_static! {
     static ref CLIENT: Client = {
-        let mut client = Client::new().unwrap();
+        let mut client = Client::new().expect("Failed to create Client!");
         // The login site redirects to itself if no redirect parameter is given
         client.redirect(RedirectPolicy::none());
         client
@@ -55,8 +54,14 @@ struct Presentation {
 impl<'a> From<&'a JsonValue> for Presentation {
     fn from(json: &'a JsonValue) -> Presentation {
         Presentation {
-            name: json["Name"].clone().take_string().unwrap(),
+            name: json["Name"]
-            download_url: json["DownloadUrls"][0]["Url"].clone().take_string().unwrap(),
+                .clone()
+                .take_string()
+                .expect("json: Presentation didn't contain a \"Name\"!"),
+            download_url: json["DownloadUrls"][0]["Url"]
+                .clone()
+                .take_string()
+                .expect("json: Presentation didn't have a download url!"),
         }
     }
 }
@@ -88,7 +93,7 @@ fn get_output_directory() -> PathBuf {
     if path.exists() {
         assert!(path.is_dir());
     } else {
-        ::std::fs::create_dir_all(path).unwrap();
+        ::std::fs::create_dir_all(path).expect("Failed to create output directory!");
     }
     path.to_owned()
 }
@@ -108,13 +113,15 @@ fn get_auth(username: &str, password: &str) -> String {
     form_data.insert("UserName", username);
     form_data.insert("Password", password);
 
-    let res = try_to_get_response(|client| {
+    let res = try_to_get_valid_response(|client| {
-        client.post("https://streams.tum.de/Mediasite/Login")
+                                            client.post("https://streams.tum.de/Mediasite/Login")
-            .form(&form_data)
+                                                .form(&form_data)
-    });
+                                        },
+                                        |res| res.headers().get::<SetCookie>().is_some());
 
     let set_cookie: &SetCookie = res.headers().get().unwrap();
-    let cookie = cookie::Cookie::parse(set_cookie.0[0].to_string()).unwrap();
+    let cookie = cookie::Cookie::parse(set_cookie.0[0].to_string())
+        .expect("Failed to parse SetCookie");
     assert_eq!(cookie.name(), "MediasiteAuth");
 
     cookie.value().to_string()
@@ -141,16 +148,15 @@ fn get_catalog_id(name: &str, auth: &str) -> String {
 
     let url = format!("https://streams.tum.de/Mediasite/Catalog/catalogs/{}", name);
     let mut res = try_to_get_response(|client| client.get(&url).header(construct_cookie(auth)));
-    let mut string = String::new();
+    let body = read_response_body(&mut res);
-    res.read_to_string(&mut string).unwrap();
 
     let prefix = "CatalogId: '";
-    let idx = string.find(prefix).unwrap();
+    let idx = body.find(prefix).expect("Failed to find CatalogId on the catalog page!");
     let pre_len = prefix.len();
     // Assuming all catalog ids follow this pattern!
     let len = "a6fca0c1-0be4-4e66-83b7-bcdc4eb5e95e".len();
 
-    string[(idx + pre_len)..(idx + pre_len + len)].to_string()
+    body[(idx + pre_len)..(idx + pre_len + len)].to_string()
 }
 
 fn download_presentation(presentation: &Presentation, out_dir: &Path, auth: &str) {
@@ -169,7 +175,8 @@ fn download_presentation(presentation: &Presentation, out_dir: &Path, auth: &str
             match *param {
                 DispositionParam::Filename(ref charset, _, ref vec) => {
                     assert_eq!(&Charset::Ext("UTF-8".to_string()), charset);
-                    name = Some(String::from_utf8(vec.to_vec()).unwrap());
+                    name = Some(String::from_utf8(vec.to_vec())
+                        .expect("Suggested filename isn't valid UTF-8!"));
                 }
                 _ => continue,
             }
@@ -191,7 +198,7 @@ fn download_presentation(presentation: &Presentation, out_dir: &Path, auth: &str
             // http://stackoverflow.com/questions/3428102/
         }
     }
-    let mut file = File::create(&path).unwrap();
+    let mut file = File::create(&path).expect("Failed to create file!");
 
     let mut reader = BufReader::new(response);
     let mut buf = [0u8; 8 * 1024];
@@ -208,7 +215,7 @@ fn download_presentation(presentation: &Presentation, out_dir: &Path, auth: &str
             Err(e) => panic!(e),
         };
 
-        file.write_all(&buf[0..len]).unwrap();
+        file.write_all(&buf[0..len]).expect("Failed writing into the file!");
         done += len;
 
         let now = Instant::now();
@@ -216,7 +223,7 @@ fn download_presentation(presentation: &Presentation, out_dir: &Path, auth: &str
             print!("{:.*} kB/s\r",
                    2,
                    done as f64 * 1000.0 / update_duration_millis as f64 / 1024.0);
-            std::io::stdout().flush().unwrap();
+            std::io::stdout().flush().expect("Failed flushing the terminal!");
             last = now;
             done = 0;
         }
@@ -232,7 +239,7 @@ fn fix_filename(string: &str) -> String {
 
 fn json_to_presentations(json_str: &str) -> Vec<Presentation> {
     let mut vec = Vec::new();
-    let mut json = json::parse(json_str).unwrap();
+    let mut json = json::parse(json_str).expect("Failed parsing the json!");
     let mut count = 0;
     for presentation in json["PresentationDetailsList"].members_mut() {
         assert_eq!(1, presentation["DownloadUrls"].len());
@@ -256,9 +263,7 @@ fn get_json(catalog_id: &str, auth: &str) -> String {
             .header(construct_cookie(auth))
             .json(&data)
     });
-    let mut string = String::new();
+    read_response_body(&mut res)
-    res.read_to_string(&mut string).unwrap();
-    string
 }
 
 fn construct_cookie(auth: &str) -> Cookie {
@@ -268,7 +273,7 @@ fn construct_cookie(auth: &str) -> Cookie {
 fn zip_is_valid(path: &Path) -> bool {
     assert!(path.exists());
     assert!(path.is_file());
-    let file = File::open(path).unwrap();
+    let file = File::open(path).expect("Failed opening the zip file!");
     ZipArchive::new(file).is_ok()
 }
 
@@ -295,5 +300,11 @@ fn try_to_get_valid_response<F1, F2>(f1: F1, f2: F2) -> Response
         }
         retries += 1;
     }
-    panic!("Reached maximum amout of retries!")
+    panic!("Reached maximum amount of retries!")
+}
+
+fn read_response_body(response: &mut Response) -> String {
+    let mut string = String::new();
+    response.read_to_string(&mut string).expect("Failed to read body");
+    string
 }