feat(Validators): adds ability to validate invalid UTF-8

src/app/mod.rs

@@ -8,7 +8,7 @@ mod help;
 // Std
 use std::borrow::Borrow;
 use std::env;
-use std::ffi::OsString;
+use std::ffi::{OsStr, OsString};
 use std::fmt;
 use std::io::{self, BufRead, BufWriter, Write};
 use std::path::Path;
@@ -1525,7 +1525,7 @@ impl<'n, 'e> AnyArg<'n, 'e> for App<'n, 'e> {
     fn num_vals(&self) -> Option<u64> { None }
     fn possible_vals(&self) -> Option<&[&'e str]> { None }
     fn validator(&self) -> Option<&Rc<Fn(String) -> StdResult<(), String>>> { None }
-    fn validator_os(&self) -> Option<&Rc<Fn(String) -> StdResult<(), String>>> { None }
+    fn validator_os(&self) -> Option<&Rc<Fn(&OsStr) -> StdResult<(), OsString>>> { None }
     fn min_vals(&self) -> Option<u64> { None }
     fn short(&self) -> Option<char> { None }
     fn long(&self) -> Option<&'e str> { None }

src/app/parser.rs

@@ -1534,8 +1534,8 @@ impl<'a, 'b> Parser<'a, 'b>
             }
         }
         if let Some(vtor) = arg.validator_os() {
-            if let Err(e) = vtor(val.to_string_lossy().into_owned()) {
-                return Err(Error::value_validation(Some(arg), e, self.color()));
+            if let Err(e) = vtor(val) {
+                return Err(Error::value_validation(Some(arg), e.into_string().unwrap_or("error invalid UTF-8".to_string()), self.color()));
             }
         }
         if matcher.needs_more_vals(arg) {

src/args/any_arg.rs

@@ -1,6 +1,7 @@
 // Std
 use std::rc::Rc;
 use std::fmt as std_fmt;
+use std::ffi::{OsStr, OsString};
 
 // Third Party
 use vec_map::VecMap;
@@ -26,7 +27,7 @@ pub trait AnyArg<'n, 'e>: std_fmt::Display {
     fn num_vals(&self) -> Option<u64>;
     fn possible_vals(&self) -> Option<&[&'e str]>;
     fn validator(&self) -> Option<&Rc<Fn(String) -> Result<(), String>>>;
-    fn validator_os(&self) -> Option<&Rc<Fn(String) -> Result<(), String>>>;
+    fn validator_os(&self) -> Option<&Rc<Fn(&OsStr) -> Result<(), OsString>>>;
     fn short(&self) -> Option<char>;
     fn long(&self) -> Option<&'e str>;
     fn val_delim(&self) -> Option<char>;

src/args/arg.rs

@@ -1,6 +1,7 @@
 #[cfg(feature = "yaml")]
 use std::collections::BTreeMap;
 use std::rc::Rc;
+use std::ffi::{OsString, OsStr};
 
 #[cfg(feature = "yaml")]
 use yaml_rust::Yaml;
@@ -66,7 +67,7 @@ pub struct Arg<'a, 'b>
     #[doc(hidden)]
     pub validator: Option<Rc<Fn(String) -> Result<(), String>>>,
     #[doc(hidden)]
-    pub validator_os: Option<Rc<Fn(String) -> Result<(), String>>>,
+    pub validator_os: Option<Rc<Fn(&OsStr) -> Result<(), OsString>>>,
     #[doc(hidden)]
     pub overrides: Option<Vec<&'a str>>,
     #[doc(hidden)]
@@ -1915,7 +1916,7 @@ impl<'a, 'b> Arg<'a, 'b> {
     /// # Examples
     /// ```rust
     /// # use clap::{App, Arg};
-    ///fn has_ampersand(v: String) -> Result<(), String> {
+    ///fn has_ampersand(v: &OsStr) -> Result<(), String> {
     ///     if v.contains("&") { return Ok(()); }
     ///     Err(String::from("The value did not contain the required & sigil"))
     /// }
@@ -1930,13 +1931,15 @@ impl<'a, 'b> Arg<'a, 'b> {
     /// assert_eq!(res.unwrap().value_of("file"), Some("Fish & chips"));
     /// ```
     /// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html
+    /// [`OsStr`]: https://doc.rust-lang.org/std/ffi/struct.OsStr.html
+    /// [`OsString`]: https://doc.rust-lang.org/std/ffi/struct.OsString.html
     /// [`Result`]: https://doc.rust-lang.org/std/result/enum.Result.html
     /// [`Err(String)`]: https://doc.rust-lang.org/std/result/enum.Result.html#variant.Err
     /// [`Rc`]: https://doc.rust-lang.org/std/rc/struct.Rc.html
     pub fn validator_os<F>(mut self, f: F) -> Self
-        where F: Fn(String) -> Result<(), String> + 'static
+        where F: Fn(&OsStr) -> Result<(), OsString> + 'static
     {
-        self.validator = Some(Rc::new(f));
+        self.validator_os = Some(Rc::new(f));
         self
     }
 

src/args/arg_builder/flag.rs

@@ -3,6 +3,7 @@ use std::convert::From;
 use std::fmt::{Display, Formatter, Result};
 use std::rc::Rc;
 use std::result::Result as StdResult;
+use std::ffi::{OsStr, OsString};
 
 // Third Party
 use vec_map::VecMap;
@@ -64,7 +65,7 @@ impl<'n, 'e> AnyArg<'n, 'e> for FlagBuilder<'n, 'e> {
     fn num_vals(&self) -> Option<u64> { None }
     fn possible_vals(&self) -> Option<&[&'e str]> { None }
     fn validator(&self) -> Option<&Rc<Fn(String) -> StdResult<(), String>>> { None }
-    fn validator_os(&self) -> Option<&Rc<Fn(String) -> StdResult<(), String>>> { None }
+    fn validator_os(&self) -> Option<&Rc<Fn(&OsStr) -> StdResult<(), OsString>>> { None }
     fn min_vals(&self) -> Option<u64> { None }
     fn short(&self) -> Option<char> { self.s.short }
     fn long(&self) -> Option<&'e str> { self.s.long }

src/args/arg_builder/option.rs

@@ -2,6 +2,7 @@
 use std::fmt::{Display, Formatter, Result};
 use std::rc::Rc;
 use std::result::Result as StdResult;
+use std::ffi::{OsStr, OsString};
 
 // Third Party
 use vec_map::VecMap;
@@ -107,7 +108,7 @@ impl<'n, 'e> AnyArg<'n, 'e> for OptBuilder<'n, 'e> {
     fn validator(&self) -> Option<&Rc<Fn(String) -> StdResult<(), String>>> {
         self.v.validator.as_ref()
     }
-    fn validator_os(&self) -> Option<&Rc<Fn(String) -> StdResult<(), String>>> {
+    fn validator_os(&self) -> Option<&Rc<Fn(&OsStr) -> StdResult<(), OsString>>> {
         self.v.validator_os.as_ref()
     }
     fn min_vals(&self) -> Option<u64> { self.v.min_vals }

src/args/arg_builder/positional.rs

@@ -3,6 +3,7 @@ use std::borrow::Cow;
 use std::fmt::{Display, Formatter, Result};
 use std::rc::Rc;
 use std::result::Result as StdResult;
+use std::ffi::{OsStr, OsString};
 
 // Third Party
 use vec_map::VecMap;
@@ -111,7 +112,7 @@ impl<'n, 'e> AnyArg<'n, 'e> for PosBuilder<'n, 'e> {
     fn validator(&self) -> Option<&Rc<Fn(String) -> StdResult<(), String>>> {
         self.v.validator.as_ref()
     }
-    fn validator_os(&self) -> Option<&Rc<Fn(String) -> StdResult<(), String>>> {
+    fn validator_os(&self) -> Option<&Rc<Fn(&OsStr) -> StdResult<(), OsString>>> {
         self.v.validator_os.as_ref()
     }
     fn min_vals(&self) -> Option<u64> { self.v.min_vals }

src/args/arg_builder/valued.rs

@@ -1,4 +1,5 @@
 use std::rc::Rc;
+use std::ffi::{OsStr, OsString};
 
 use vec_map::VecMap;
 
@@ -15,7 +16,7 @@ pub struct Valued<'a, 'b>
     pub max_vals: Option<u64>,
     pub min_vals: Option<u64>,
     pub validator: Option<Rc<Fn(String) -> Result<(), String>>>,
-    pub validator_os: Option<Rc<Fn(String) -> Result<(), String>>>,
+    pub validator_os: Option<Rc<Fn(&OsStr) -> Result<(), OsString>>>,
     pub val_delim: Option<char>,
     pub default_val: Option<&'a str>,
 }