From 8b09d7a602e05227673510468ef65255dd1f4f7a Mon Sep 17 00:00:00 2001
From: kngwyu <yuji.kngw.80s.revive@gmail.com>
Date: Fri, 17 Aug 2018 17:13:15 +0900
Subject: [PATCH 1/3] Allow variant with no #fail attribute

If a variant doesn't have fail atrribute, use its' name to display
---
 failure_derive/src/lib.rs     | 14 +++++++-------
 failure_derive/tests/tests.rs | 24 ++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/failure_derive/src/lib.rs b/failure_derive/src/lib.rs
index 230d2ee..9c0c5d8 100644
--- a/failure_derive/src/lib.rs
+++ b/failure_derive/src/lib.rs
@@ -69,14 +69,14 @@ fn fail_derive(s: synstructure::Structure) -> TokenStream {
 }
 
 fn display_body(s: &synstructure::Structure) -> Option<quote::__rt::TokenStream> {
-    let mut msgs = s.variants().iter().map(|v| find_error_msg(&v.ast().attrs));
-    if msgs.all(|msg| msg.is_none()) {
-        return None;
-    }
-
     Some(s.each_variant(|v| {
-        let msg =
-            find_error_msg(&v.ast().attrs).expect("All variants must have display attribute.");
+        let msg = match find_error_msg(&v.ast().attrs) {
+            Some(msg) => msg,
+            None => {
+                let variant_name = v.ast().ident.to_string();
+                return quote!( return write!(f, "{}", #variant_name));
+            }
+        };
         if msg.nested.is_empty() {
             panic!("Expected at least one argument to fail attribute");
         }
diff --git a/failure_derive/tests/tests.rs b/failure_derive/tests/tests.rs
index 4e73255..a632276 100644
--- a/failure_derive/tests/tests.rs
+++ b/failure_derive/tests/tests.rs
@@ -53,3 +53,27 @@ fn enum_error() {
     let s = format!("{}", EnumError::UnitVariant);
     assert_eq!(&s[..], "An error has occurred.");
 }
+
+#[derive(Debug, Fail)]
+enum EnumWithNoAttr {
+    #[fail(display = "Error: {}", _0)]
+    TupleVariant(usize),
+    UnitVariant,
+}
+
+#[test]
+fn enum_with_no_attr() {
+    let s = format!("{}", EnumWithNoAttr::TupleVariant(4));
+    assert_eq!(&s[..], "Error: 4");
+    let s = format!("{}", EnumWithNoAttr::UnitVariant);
+    assert_eq!(&s[..], "UnitVariant");
+}
+
+#[derive(Debug, Fail)]
+struct StructWithNoAttr;
+
+#[test]
+fn struct_with_no_attr() {
+    let s = format!("{}", StructWithNoAttr {});
+    assert_eq!(&s[..], "StructWithNoAttr");
+}

From 489255974d4a2bb36dce1ee6b1c8034993a17bc0 Mon Sep 17 00:00:00 2001
From: kngwyu <yuji.kngw.80s.revive@gmail.com>
Date: Sat, 18 Aug 2018 11:39:23 +0900
Subject: [PATCH 2/3] Use Debug::fmt instead of variant name

---
 failure_derive/src/lib.rs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/failure_derive/src/lib.rs b/failure_derive/src/lib.rs
index 9c0c5d8..e22f1c0 100644
--- a/failure_derive/src/lib.rs
+++ b/failure_derive/src/lib.rs
@@ -73,8 +73,7 @@ fn display_body(s: &synstructure::Structure) -> Option<quote::__rt::TokenStream>
         let msg = match find_error_msg(&v.ast().attrs) {
             Some(msg) => msg,
             None => {
-                let variant_name = v.ast().ident.to_string();
-                return quote!( return write!(f, "{}", #variant_name));
+                return quote!(return write!(f, "{:?}", self));
             }
         };
         if msg.nested.is_empty() {

From 49fd080596f83a38a884821ad4f8d36d1f8fbae9 Mon Sep 17 00:00:00 2001
From: kngwyu <yuji.kngw.80s.revive@gmail.com>
Date: Sat, 18 Aug 2018 11:40:08 +0900
Subject: [PATCH 3/3] Add --all flag to travis

---
 .travis.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.travis.yml b/.travis.yml
index 61d8965..f52b5cd 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,6 +6,6 @@ rust:
     - nightly
 cache: cargo
 script:
-  - cargo test
+  - cargo test --all
   - cargo test --features backtrace
   - cargo check --no-default-features