From 613074dff126f4bc6cb96a65d745154d23ff2dc8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vin=C3=ADcius=20Miguel?= <lemao.vrm07@hotmail.com>
Date: Wed, 7 Apr 2021 23:36:58 -0300
Subject: [PATCH] oof: add error variant DuplicatedFlag

---
 oof/src/error.rs | 6 ++++--
 oof/src/lib.rs   | 8 ++++----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/oof/src/error.rs b/oof/src/error.rs
index fd3675c..f1435ca 100644
--- a/oof/src/error.rs
+++ b/oof/src/error.rs
@@ -14,7 +14,8 @@ pub enum OofError<'t> {
     /// User supplied an unrecognized short flag
     UnknownShortFlag(char),
     MisplacedShortArgFlagError(char),
-    MissingValueToFlag(&'t Flag)
+    MissingValueToFlag(&'t Flag),
+    DuplicatedFlag(&'t Flag)
 }
 
 impl<'t> error::Error for OofError<'t> {
@@ -39,7 +40,8 @@ impl<'t> fmt::Display for OofError<'t> {
             OofError::InvalidUnicode(flag) => write!(f, "{:?} is not valid Unicode.", flag),
             OofError::UnknownShortFlag(ch) => write!(f, "Unknown argument '-{}'", ch),
             OofError::MisplacedShortArgFlagError(ch) => write!(f, "Invalid placement of `-{}`.\nOnly the last letter in a sequence of short flags can take values.", ch),
-            OofError::MissingValueToFlag(flag) => write!(f, "Flag {} takes value but none was supplied.", flag)
+            OofError::MissingValueToFlag(flag) => write!(f, "Flag {} takes value but none was supplied.", flag),
+            OofError::DuplicatedFlag(flag) => write!(f, "Duplicated usage of {}.", flag),
         }
     }
 }
diff --git a/oof/src/lib.rs b/oof/src/lib.rs
index 2763f30..4fc65d1 100644
--- a/oof/src/lib.rs
+++ b/oof/src/lib.rs
@@ -143,7 +143,7 @@ pub fn filter_flags(
                 if flag_info.takes_value {
                     // If it was already inserted
                     if result_flags.argument_flags.contains_key(flag_name) {
-                        panic!("User error: duplicated, found this flag TWICE!");
+                        return Err(OofError::DuplicatedFlag(flag_info));
                     }
 
                     // pop the next one
@@ -156,7 +156,7 @@ pub fn filter_flags(
                 } else {
                     // If it was already inserted
                     if result_flags.boolean_flags.contains(flag_name) {
-                        panic!("User error: duplicated, found this flag TWICE!");
+                        return Err(OofError::DuplicatedFlag(flag_info));
                     }
                     // Otherwise, insert it
                     result_flags.boolean_flags.insert(flag_name);
@@ -176,7 +176,7 @@ pub fn filter_flags(
             if flag_info.takes_value {
                 // If it was already inserted
                 if result_flags.argument_flags.contains_key(&flag_name) {
-                    panic!("User error: duplicated, found this flag TWICE!");
+                    return Err(OofError::DuplicatedFlag(flag_info));
                 }
 
                 let flag_argument = iter.next().unwrap_or_else(|| {
@@ -189,7 +189,7 @@ pub fn filter_flags(
             } else {
                 // If it was already inserted
                 if result_flags.boolean_flags.contains(&flag_name) {
-                    panic!("User error: duplicated, found this flag TWICE!");
+                    return Err(OofError::DuplicatedFlag(flag_info));
                 }
                 // Otherwise, insert it
                 result_flags.boolean_flags.insert(&flag_name);