make it possible to specify an empty user-agent string

src/main.rs

@@ -114,10 +114,12 @@ fn main() {
     // Initialize client
     let mut cache = HashMap::new();
     let mut header_map = HeaderMap::new();
-    header_map.insert(
+    if let Some(user_agent) = &options.user_agent {
-        USER_AGENT,
+        header_map.insert(
-        HeaderValue::from_str(&options.user_agent).expect("Invalid User-Agent header specified"),
+            USER_AGENT,
-    );
+            HeaderValue::from_str(&user_agent).expect("Invalid User-Agent header specified"),
+        );
+    }
     let timeout: u64 = if options.timeout > 0 {
         options.timeout
     } else {

src/opts.rs

@@ -16,7 +16,7 @@ pub struct Options {
     pub output: String,
     pub silent: bool,
     pub timeout: u64,
-    pub user_agent: String,
+    pub user_agent: Option<String>,
     pub no_video: bool,
     pub target: String,
 }
@@ -38,7 +38,7 @@ impl Options {
     pub fn from_args() -> Options {
         let app = App::new(env!("CARGO_PKG_NAME"))
             .version(crate_version!())
-            .author(crate_authors!("\n"))
+            .author(format!("\n{}", crate_authors!("\n")).as_str())
             .about(format!("{}\n{}", ASCII, crate_description!()).as_str())
             .args_from_usage("-a, --no-audio 'Removes audio sources'")
             .args_from_usage("-b, --base-url=[http://localhost/] 'Sets custom base URL'")
@@ -61,7 +61,7 @@ impl Options {
                     .required(true)
                     .takes_value(true)
                     .index(1)
-                    .help("URL or file path"),
+                    .help("URL or file path, use - for stdin"),
             )
             .get_matches();
         let mut options: Options = Options::default();
@@ -91,10 +91,11 @@ impl Options {
             .unwrap_or(&DEFAULT_NETWORK_TIMEOUT.to_string())
             .parse::<u64>()
             .unwrap();
-        options.user_agent = app
+        if let Some(user_agent) = app.value_of("user-agent") {
-            .value_of("user-agent")
+            options.user_agent = Some(str!(user_agent));
-            .unwrap_or(DEFAULT_USER_AGENT)
+        } else {
-            .to_string();
+            options.user_agent = Some(DEFAULT_USER_AGENT.to_string());
+        }
         options.no_video = app.is_present("no-video");
 
         options

src/tests/opts.rs

@@ -13,8 +13,8 @@ mod passing {
     fn defaults() {
         let options: Options = Options::default();
 
-        assert_eq!(options.target, str!());
         assert_eq!(options.no_audio, false);
+        assert_eq!(options.base_url, None);
         assert_eq!(options.no_css, false);
         assert_eq!(options.no_frames, false);
         assert_eq!(options.no_fonts, false);
@@ -26,7 +26,9 @@ mod passing {
         assert_eq!(options.output, str!());
         assert_eq!(options.silent, false);
         assert_eq!(options.timeout, 0);
-        assert_eq!(options.user_agent, "");
+        assert_eq!(options.user_agent, None);
         assert_eq!(options.no_video, false);
+
+        assert_eq!(options.target, str!());
     }
 }