fix(Safe Matches): using 'safe' forms of the get_matches family no lo…

…nger exit the process

Closes #256

src/app/app.rs

@@ -1670,7 +1670,9 @@ impl<'a, 'v, 'ab, 'u, 'h, 'ar> App<'a, 'v, 'ab, 'u, 'h, 'ar>{
                 // Callers still use &[""]
                 assert_eq!(data.len(), 1);
                 "Invalid unicode character in one or more arguments".to_owned()
-            }
+            },
+            // HelpDisplayed, VersionDisplayed
+            _ => unreachable!()
         };
 
         ClapError {
@@ -1741,6 +1743,11 @@ impl<'a, 'v, 'ab, 'u, 'h, 'ar> App<'a, 'v, 'ab, 'u, 'h, 'ar>{
     /// Starts the parsing process. Called on top level parent app **ONLY** then recursively calls
     /// the real parsing function for all subcommands
     ///
+    /// **NOTE:** This method WILL NOT exit when `--help` or `--version` (or short versions) are
+    /// used. It will return an error, where the `error_type` is a `ClapErrorType::HelpDisplayed`
+    /// or `ClapErrorType::VersionDisplayed` respectively. You must call `error.exit()` or
+    /// perform a `std::process::exit` yourself.
+    ///
     /// **NOTE:** This method should only be used when is absolutely necessary to handle errors
     /// manually.
     ///
@@ -1763,6 +1770,11 @@ impl<'a, 'v, 'ab, 'u, 'h, 'ar> App<'a, 'v, 'ab, 'u, 'h, 'ar>{
     /// the real parsing function for all subcommands. Invalid unicode characters are replaced with
     /// `U+FFFD REPLACEMENT CHARACTER`
     ///
+    /// **NOTE:** This method WILL NOT exit when `--help` or `--version` (or short versions) are
+    /// used. It will return an error, where the `error_type` is a `ClapErrorType::HelpDisplayed`
+    /// or `ClapErrorType::VersionDisplayed` respectively. You must call `error.exit()` or
+    /// perform a `std::process::exit` yourself.
+    ///
     /// **NOTE:** This method should only be used when is absolutely necessary to handle errors
     /// manually.
     ///
@@ -1809,6 +1821,10 @@ impl<'a, 'v, 'ab, 'u, 'h, 'ar> App<'a, 'v, 'ab, 'u, 'h, 'ar>{
         match self.get_matches_from_safe_borrow(itr) {
             Ok(m) => return m,
             Err(e) => {
+                match e.error_type {
+                    ClapErrorType::HelpDisplayed | ClapErrorType::VersionDisplayed => e.exit(),
+                    _ => ()
+                }
                 wlnerr!("{}", e.error);
                 if self.settings.is_set(&AppSettings::WaitOnError) {
                     wlnerr!("\nPress [ENTER] / [RETURN] to continue...");
@@ -1850,6 +1866,10 @@ impl<'a, 'v, 'ab, 'u, 'h, 'ar> App<'a, 'v, 'ab, 'u, 'h, 'ar>{
         match self.get_matches_from_safe_borrow_lossy(itr) {
             Ok(m) => return m,
             Err(e) => {
+                match e.error_type {
+                    ClapErrorType::HelpDisplayed | ClapErrorType::VersionDisplayed => e.exit(),
+                    _ => ()
+                }
                 wlnerr!("{}", e.error);
                 if self.settings.is_set(&AppSettings::WaitOnError) {
                     wlnerr!("\nPress [ENTER] / [RETURN] to continue...");
@@ -1865,6 +1885,11 @@ impl<'a, 'v, 'ab, 'u, 'h, 'ar> App<'a, 'v, 'ab, 'u, 'h, 'ar>{
     /// Starts the parsing process. Called on top level parent app **ONLY** then recursively calls
     /// the real parsing function for all subcommands
     ///
+    /// **NOTE:** This method WILL NOT exit when `--help` or `--version` (or short versions) are
+    /// used. It will return an error, where the `error_type` is a `ClapErrorType::HelpDisplayed`
+    /// or `ClapErrorType::VersionDisplayed` respectively. You must call `error.exit()` or
+    /// perform a `std::process::exit` yourself.
+    ///
     /// **NOTE:** The first argument will be parsed as the binary name.
     ///
     /// **NOTE:** This method should only be used when absolutely necessary, such as needing to
@@ -1901,6 +1926,11 @@ impl<'a, 'v, 'ab, 'u, 'h, 'ar> App<'a, 'v, 'ab, 'u, 'h, 'ar>{
     /// the real parsing function for all subcommands. Invalid unicode characters are replaced with
     /// `U+FFFD REPLACEMENT CHARACTER`
     ///
+    /// **NOTE:** This method WILL NOT exit when `--help` or `--version` (or short versions) are
+    /// used. It will return an error, where the `error_type` is a `ClapErrorType::HelpDisplayed`
+    /// or `ClapErrorType::VersionDisplayed` respectively. You must call `error.exit()` or
+    /// perform a `std::process::exit` yourself.
+    ///
     /// **NOTE:** The first argument will be parsed as the binary name.
     ///
     /// **NOTE:** This method should only be used when absolutely necessary, such as needing to
@@ -2292,7 +2322,11 @@ impl<'a, 'v, 'ab, 'u, 'h, 'ar> App<'a, 'v, 'ab, 'u, 'h, 'ar>{
                                     error_type: ClapErrorType::MissingSubcommand
                                 });
                             }
-                            process::exit(0);
+                            // process::exit(0);
+                            return Err(ClapError{
+                                error: String::new(),
+                                error_type: ClapErrorType::HelpDisplayed
+                            })
                         }
                         subcmd_name = Some(arg_slice.to_owned());
                         break;
@@ -2696,19 +2730,41 @@ impl<'a, 'v, 'ab, 'u, 'h, 'ar> App<'a, 'v, 'ab, 'u, 'h, 'ar>{
 
     fn check_for_help_and_version(&self,
                                   arg: char)
-                                  -> io::Result<()> {
+                                  -> Result<(), ClapError> {
         if let Some(h) = self.help_short {
             if h == arg {
-                try!(self.print_help());
-                process::exit(0);
+                if let Err(e) = self.print_help() {
+                    return Err(ClapError{
+                        error: format!("{} {}\n\terror message: {}\n",
+                                        Format::Error("error:"),
+                                        INTERNAL_ERROR_MSG, e.description()),
+                        error_type: ClapErrorType::MissingSubcommand
+                    });
+                }
+                // process::exit(0);
+                return Err(ClapError{
+                    error: String::new(),
+                    error_type: ClapErrorType::HelpDisplayed
+                })
             }
         }
         if let Some(v) = self.version_short {
             if v == arg {
                 let out = io::stdout();
                 let mut buf_w = BufWriter::new(out.lock());
-                try!(self.print_version(&mut buf_w));
-                process::exit(0);
+                if let Err(e) = self.print_version(&mut buf_w) {
+                    return Err(ClapError{
+                        error: format!("{} {}\n\terror message: {}\n",
+                                        Format::Error("error:"),
+                                        INTERNAL_ERROR_MSG, e.description()),
+                        error_type: ClapErrorType::MissingSubcommand
+                    });
+                }
+                // process::exit(0);
+                return Err(ClapError{
+                    error: String::new(),
+                    error_type: ClapErrorType::VersionDisplayed
+                })
             }
         }
 
@@ -2730,7 +2786,11 @@ impl<'a, 'v, 'ab, 'u, 'h, 'ar> App<'a, 'v, 'ab, 'u, 'h, 'ar>{
                     error_type: ClapErrorType::MissingSubcommand
                 });
             }
-            process::exit(0);
+            return Err(ClapError{
+                error: String::new(),
+                error_type: ClapErrorType::HelpDisplayed
+            })
+            // process::exit(0);
         } else if arg == "version" && self.settings.is_set(&AppSettings::NeedsLongVersion) {
             let out = io::stdout();
             let mut buf_w = BufWriter::new(out.lock());
@@ -2742,7 +2802,11 @@ impl<'a, 'v, 'ab, 'u, 'h, 'ar> App<'a, 'v, 'ab, 'u, 'h, 'ar>{
                     error_type: ClapErrorType::MissingSubcommand
                 });
             }
-            process::exit(0);
+            return Err(ClapError{
+                error: String::new(),
+                error_type: ClapErrorType::VersionDisplayed
+            })
+            // process::exit(0);
         }
 
         let mut arg_val: Option<&'av str> = None;

src/app/errors.rs

@@ -219,7 +219,38 @@ pub enum ClapErrorType {
     ///                                 OsString::from_vec(vec![0xE9])]);
     /// assert!(result.is_err());
     /// ```
-    InvalidUnicode
+    InvalidUnicode,
+    /// Not a true 'error' as it means `--help` or similar was used. The help message will be sent
+    /// to `stdout` unless the help is displayed due to an error (such as missing subcommands) at
+    /// which point it will be sent to `stderr`
+    ///
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// # use clap::ClapErrorType;
+    /// let result = App::new("myprog")
+    ///     .get_matches_from_safe(vec!["", "--help"]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().error_type, ClapErrorType::HelpDisplayed);
+    /// ```
+    HelpDisplayed,
+    /// Not a true 'error' as it means `--version` or similar was used. The message will be sent
+    /// to `stdout` 
+    ///
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # use clap::{App, Arg};
+    /// # use clap::ClapErrorType;
+    /// let result = App::new("myprog")
+    ///     .get_matches_from_safe(vec!["", "--version"]);
+    /// assert!(result.is_err());
+    /// assert_eq!(result.unwrap_err().error_type, ClapErrorType::VersionDisplayed);
+    /// ```
+    VersionDisplayed
 }
 
 /// Command line argument parser error

src/args/argmatches.rs

@@ -52,6 +52,7 @@ use args::MatchedArg;
 ///         println!("Not printing testing lists...");
 ///     }
 /// }
+#[derive(Debug)]
 pub struct ArgMatches<'n, 'a> {
     #[doc(hidden)]
     pub args: HashMap<&'a str, MatchedArg>,

src/args/matchedarg.rs

@@ -1,6 +1,7 @@
 use std::collections::BTreeMap;
 
 #[doc(hidden)]
+#[derive(Debug)]
 pub struct MatchedArg {
     // #[doc(hidden)]
     // pub name: String,

src/args/subcommand.rs

@@ -23,6 +23,7 @@ use ArgMatches;
 ///                           .help("The configuration file to use")
 ///                           .index(1))
 /// # ).get_matches();
+#[derive(Debug)]
 pub struct SubCommand<'n, 'a> {
     #[doc(hidden)]
     pub name: &'n str,