From 00a0b9660a9d6b30984c64f27a3975194fcd8087 Mon Sep 17 00:00:00 2001
From: Pavan Kumar Sunkara <pavan.sss1991@gmail.com>
Date: Thu, 9 Apr 2020 14:03:52 +0200
Subject: [PATCH] Assert for require* on args

---
 src/build/app/mod.rs | 37 +++++++++++++++++++++++++++++++---
 src/build/arg/mod.rs | 18 ++++++-----------
 tests/require.rs     | 48 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 88 insertions(+), 15 deletions(-)

diff --git a/src/build/app/mod.rs b/src/build/app/mod.rs
index 611603a2..6aa869b8 100644
--- a/src/build/app/mod.rs
+++ b/src/build/app/mod.rs
@@ -1523,13 +1523,44 @@ impl<'b> App<'b> {
                     } else {
                         acc
                     }) < 2,
-                    "Argument '{}' has the same index as another positional \
-                 argument\n\n\tUse Arg::setting(ArgSettings::MultipleValues) to allow one \
-                 positional argument to take multiple values",
+                    "Argument '{}' has the same index as another positional argument\n\n\t \
+                    Use Arg::setting(ArgSettings::MultipleValues) to allow one \
+                    positional argument to take multiple values",
                     arg.name
                 );
             }
 
+            // requires, r_if, r_unless
+            if let Some(reqs) = &arg.requires {
+                for req in reqs {
+                    assert!(
+                        self.args.args.iter().any(|x| x.id == req.1),
+                        "Argument specified in 'requires*' for '{}' does not exist",
+                        arg.name,
+                    );
+                }
+            }
+
+            if let Some(reqs) = &arg.r_ifs {
+                for req in reqs {
+                    assert!(
+                        self.args.args.iter().any(|x| x.id == req.0),
+                        "Argument specified in 'required_if*' for '{}' does not exist",
+                        arg.name,
+                    );
+                }
+            }
+
+            if let Some(reqs) = &arg.r_unless {
+                for req in reqs {
+                    assert!(
+                        self.args.args.iter().any(|x| x.id == *req),
+                        "Argument specified in 'required_unless*' for '{}' does not exist",
+                        arg.name,
+                    );
+                }
+            }
+
             // blacklist
             if let Some(reqs) = &arg.blacklist {
                 for req in reqs {
diff --git a/src/build/arg/mod.rs b/src/build/arg/mod.rs
index 219b5180..d0afd78b 100644
--- a/src/build/arg/mod.rs
+++ b/src/build/arg/mod.rs
@@ -64,10 +64,11 @@ pub struct Arg<'help> {
     #[doc(hidden)]
     pub blacklist: Option<Vec<Id>>,
     pub(crate) settings: ArgFlags,
-    pub(crate) r_unless: Option<Vec<Id>>,
     pub(crate) overrides: Option<Vec<Id>>,
     pub(crate) groups: Option<Vec<Id>>,
     pub(crate) requires: Option<Vec<(Option<&'help str>, Id)>>,
+    pub(crate) r_ifs: Option<Vec<(Id, &'help str)>>,
+    pub(crate) r_unless: Option<Vec<Id>>,
     #[doc(hidden)]
     pub short: Option<char>,
     #[doc(hidden)]
@@ -90,7 +91,6 @@ pub struct Arg<'help> {
     pub(crate) terminator: Option<&'help str>,
     #[doc(hidden)]
     pub index: Option<u64>,
-    pub(crate) r_ifs: Option<Vec<(Id, &'help str)>>,
     #[doc(hidden)]
     pub help_heading: Option<&'help str>,
     pub(crate) global: bool,
@@ -1114,13 +1114,11 @@ impl<'help> Arg<'help> {
     /// [Conflicting]: ./struct.Arg.html#method.conflicts_with
     /// [override]: ./struct.Arg.html#method.overrides_with
     pub fn requires<T: Key>(mut self, arg_id: T) -> Self {
-        let name = arg_id.key();
+        let arg = arg_id.key();
         if let Some(ref mut vec) = self.requires {
-            vec.push((None, name));
+            vec.push((None, arg));
         } else {
-            let mut vec = vec![];
-            vec.push((None, name));
-            self.requires = Some(vec);
+            self.requires = Some(vec![(None, arg)]);
         }
         self
     }
@@ -1496,11 +1494,7 @@ impl<'help> Arg<'help> {
                 vec.push((None, s.key()));
             }
         } else {
-            let mut vec = vec![];
-            for s in names {
-                vec.push((None, s.key()));
-            }
-            self.requires = Some(vec);
+            self.requires = Some(names.iter().map(|s| (None, s.key())).collect());
         }
         self
     }
diff --git a/tests/require.rs b/tests/require.rs
index ae8f9a6a..3d39dba7 100644
--- a/tests/require.rs
+++ b/tests/require.rs
@@ -728,3 +728,51 @@ fn issue_1643_args_mutually_require_each_other() {
 
     app.get_matches_from(&["test", "-u", "hello", "-r", "farewell"]);
 }
+
+#[cfg(debug_assertions)]
+#[test]
+#[should_panic(expected = "Argument specified in 'requires*' for 'config' does not exist")]
+fn requires_invalid_arg() {
+    let _ = App::new("prog")
+        .arg(Arg::with_name("config").requires("extra").long("config"))
+        .try_get_matches_from(vec!["", "--config"]);
+}
+
+#[cfg(debug_assertions)]
+#[test]
+#[should_panic(expected = "Argument specified in 'requires*' for 'config' does not exist")]
+fn requires_if_invalid_arg() {
+    let _ = App::new("prog")
+        .arg(
+            Arg::with_name("config")
+                .requires_if("val", "extra")
+                .long("config"),
+        )
+        .try_get_matches_from(vec!["", "--config"]);
+}
+
+#[cfg(debug_assertions)]
+#[test]
+#[should_panic(expected = "Argument specified in 'required_if*' for 'config' does not exist")]
+fn required_if_invalid_arg() {
+    let _ = App::new("prog")
+        .arg(
+            Arg::with_name("config")
+                .required_if("extra", "val")
+                .long("config"),
+        )
+        .try_get_matches_from(vec!["", "--config"]);
+}
+
+#[cfg(debug_assertions)]
+#[test]
+#[should_panic(expected = "Argument specified in 'required_unless*' for 'config' does not exist")]
+fn required_unless_invalid_arg() {
+    let _ = App::new("prog")
+        .arg(
+            Arg::with_name("config")
+                .required_unless("extra")
+                .long("config"),
+        )
+        .try_get_matches_from(vec![""]);
+}