Test of get_matches_with_env

src/app/mod.rs

@@ -31,6 +31,8 @@ use errors::Result as ClapResult;
 pub use self::settings::AppSettings;
 use completions::Shell;
 
+const DEFAULT_ARGS_ENV_VAR: &'static str = "VAR";
+
 /// Used to create a representation of a command line program and all possible command line
 /// arguments. Application settings are set using the "builder pattern" with the
 /// [`App::get_matches`] family of methods being the terminal methods that starts the
@@ -1228,13 +1230,13 @@ impl<'a, 'b> App<'a, 'b> {
         self.get_matches_from_safe(&mut env::args_os())
     }
 
-    /// Similar to [`App::get_matches`] but also reads args from 
+    /// Similar to [`App::get_matches`] but also reads args from
     /// env-var `env_var_name`.
     ///
     /// Defaults to read from "VAR" if `env_var_name` is `None`.
-    pub fn get_matches_with_env(self, env_var_name: Option<String>) 
+    pub fn get_matches_with_env(self, env_var_name: Option<String>)
             -> ArgMatches<'a> {
-        let mut env_var = "VAR".to_string();
+        let mut env_var = DEFAULT_ARGS_ENV_VAR.to_string();
         if let Some(name) = env_var_name {
             env_var = name;
         }
@@ -1624,3 +1626,31 @@ impl<'n, 'e> fmt::Display for App<'n, 'e> {
         write!(f, "{}", self.p.meta.name)
     }
 }
+
+#[cfg(test)]
+mod tests {
+
+    use std::env;
+
+    use ::{Arg, App};
+    use super::DEFAULT_ARGS_ENV_VAR;
+
+
+    #[test]
+    fn test_get_matches_with_env() {
+        env::set_var(DEFAULT_ARGS_ENV_VAR, "--arg1 val1");
+        let mut matches = App::new("testprog").arg(Arg::with_name("arg1")
+                                                    .takes_value(true)
+                                                    .long("arg1"))
+                                          .get_matches_with_env(None);
+        assert_eq!(matches.value_of("arg1").unwrap(), "val1");
+
+        env::set_var("ENV_VAR_WITH_PROGRAM_ARGS", "--arg2 val2");
+        matches = App::new("testprog")
+            .arg(Arg::with_name("arg2")
+                    .takes_value(true)
+                    .long("arg2"))
+            .get_matches_with_env(Some("ENV_VAR_WITH_PROGRAM_ARGS".to_string()));
+        assert_eq!(matches.value_of("arg2").unwrap(), "val2");
+    }
+}