docs(helpers): Let service account and helper code show up in rustdoc

src/helper.rs

@@ -11,20 +11,23 @@ use serde_json;
 
 use std::io::{self, Read};
 use std::fs;
+use std::path::Path;
 
 use service_account::ServiceAccountKey;
 use types::{ConsoleApplicationSecret, ApplicationSecret};
 
-pub fn read_application_secret(file: &String) -> io::Result<ApplicationSecret> {
+/// Read an application secret from a file.
+pub fn read_application_secret(path: &Path) -> io::Result<ApplicationSecret> {
     use std::io::Read;
 
     let mut secret = String::new();
-    let mut file = try!(fs::OpenOptions::new().read(true).open(file));
+    let mut file = try!(fs::OpenOptions::new().read(true).open(path));
     try!(file.read_to_string(&mut secret));
 
     parse_application_secret(&secret)
 }
 
+/// Read an application secret from a JSON string.
 pub fn parse_application_secret(secret: &String) -> io::Result<ApplicationSecret> {
     let result: serde_json::Result<ConsoleApplicationSecret> = serde_json::from_str(secret);
     match result {
@@ -45,6 +48,8 @@ pub fn parse_application_secret(secret: &String) -> io::Result<ApplicationSecret
     }
 }
 
+/// Read a service account key from a JSON file. You can download the JSON keys from the Google
+/// Cloud Console or the respective console of your service provider.
 pub fn service_account_key_from_file(path: &String) -> io::Result<ServiceAccountKey> {
     let mut key = String::new();
     let mut file = try!(fs::OpenOptions::new().read(true).open(path));

src/lib.rs.in

@@ -31,3 +31,4 @@ pub use authenticator::{Authenticator, Retry, GetToken};
 pub use authenticator_delegate::{AuthenticatorDelegate, DefaultAuthenticatorDelegate, PollError,
                                  PollInformation};
 pub use helper::*;
+pub use service_account::*;