Removed unnecessary macro and added comments

src/build.rs

@@ -62,26 +62,8 @@ pub fn check_wasm_pack_versions() -> Result<(String, String), Error> {
 }
 
 fn wasm_pack_local_version() -> Option<String> {
-    macro_rules! otry {
-        ($e:expr) => {
-            match $e {
-                Some(e) => e,
-                None => return None,
-            }
-        };
-    }
-
-    let output = otry!(Command::new("wasm-pack").arg("--version").output().ok());
-    let version = otry!(str::from_utf8(&output.stdout).ok());
-    let mut pieces = version.split(' ');
-    if pieces.next() != Some("wasm-pack") {
-        return None;
-    }
-    otry!(pieces.next())
-        .to_string()
-        .trim()
-        .parse::<String>()
-        .ok()
+    let output = env!("CARGO_PKG_VERSION");
+    Some(output.to_string())
 }
 
 /// Get rustc's sysroot as a PathBuf

src/main.rs

@@ -68,7 +68,8 @@ fn run() -> Result<(), failure::Error> {
     run_wasm_pack(args.cmd)?;
 
     if let Ok(update_available) = update_available.try_recv() {
-        println!("There's a newer version of wasm-pack available, the new version is: {}, you are using: {}", update_available.1, update_available.0);
+        println!("There's a newer version of wasm-pack available, the new version is: {}, you are using: {}. \
+            To update, navigate to: https://rustwasm.github.io/wasm-pack/installer/", update_available.1, update_available.0);
     }
 
     Ok(())

src/manifest/mod.rs

@@ -162,7 +162,7 @@ impl Crate {
     }
 
     fn return_api_call_result(current_time: DateTime<offset::Local>) -> Option<String> {
-        Crate::call_for_wasm_pack_version().and_then(|v| {
+        Crate::return_latest_wasm_pack_version().and_then(|v| {
             Crate::override_stamp_file(current_time, &v);
             Some(v)
         })
@@ -188,6 +188,7 @@ impl Crate {
         }
     }
 
+    /// Return stamp file where metadata is stored.
     fn return_wasm_pack_file() -> Option<String> {
         if let Ok(path) = which::which("wasm-pack") {
             if let Ok(file) = fs::read_to_string(path.with_extension("stamp")) {
@@ -197,13 +198,15 @@ impl Crate {
         None
     }
 
-    fn call_for_wasm_pack_version() -> Option<String> {
+    /// Returns wasm-pack latest version (if it's received) by executing check_wasm_pack_latest_version function.
+    fn return_latest_wasm_pack_version() -> Option<String> {
         if let Ok(crt) = Crate::check_wasm_pack_latest_version() {
             return Some(crt.crt.max_version);
         }
         None
     }
 
+    /// Read the stamp file and return value assigned to a certain key.
     fn return_stamp_file_value(file: &String, word: &str) -> Option<String> {
         let created = file
             .lines()