From 2368aa8e97e9f3d3df1a75dc798e0e3f4cced7da Mon Sep 17 00:00:00 2001
From: Yuki OKUSHI <huyuumi.dev@gmail.com>
Date: Wed, 27 Mar 2019 19:30:33 +0900
Subject: [PATCH] Add some tests

---
 .../existential-types-with-cycle-error.rs     | 12 ++++++++
 .../existential-types-with-cycle-error.stderr | 30 +++++++++++++++++++
 .../existential-types-with-cycle-error2.rs    | 16 ++++++++++
 ...existential-types-with-cycle-error2.stderr | 30 +++++++++++++++++++
 4 files changed, 88 insertions(+)
 create mode 100644 src/test/ui/existential_types/existential-types-with-cycle-error.rs
 create mode 100644 src/test/ui/existential_types/existential-types-with-cycle-error.stderr
 create mode 100644 src/test/ui/existential_types/existential-types-with-cycle-error2.rs
 create mode 100644 src/test/ui/existential_types/existential-types-with-cycle-error2.stderr

diff --git a/src/test/ui/existential_types/existential-types-with-cycle-error.rs b/src/test/ui/existential_types/existential-types-with-cycle-error.rs
new file mode 100644
index 00000000000..3f0190892eb
--- /dev/null
+++ b/src/test/ui/existential_types/existential-types-with-cycle-error.rs
@@ -0,0 +1,12 @@
+#![feature(existential_type)]
+
+existential type Foo: Fn() -> Foo;
+//~^ ERROR: cycle detected when processing `Foo`
+
+fn crash(x: Foo) -> Foo {
+    x
+}
+
+fn main() {
+
+}
diff --git a/src/test/ui/existential_types/existential-types-with-cycle-error.stderr b/src/test/ui/existential_types/existential-types-with-cycle-error.stderr
new file mode 100644
index 00000000000..56057a9caa4
--- /dev/null
+++ b/src/test/ui/existential_types/existential-types-with-cycle-error.stderr
@@ -0,0 +1,30 @@
+error[E0391]: cycle detected when processing `Foo`
+  --> $DIR/existential-types-with-cycle-error.rs:3:1
+   |
+LL | existential type Foo: Fn() -> Foo;
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: ...which requires processing `crash`...
+  --> $DIR/existential-types-with-cycle-error.rs:6:25
+   |
+LL |   fn crash(x: Foo) -> Foo {
+   |  _________________________^
+LL | |     x
+LL | | }
+   | |_^
+   = note: ...which again requires processing `Foo`, completing the cycle
+note: cycle used when collecting item types in top-level module
+  --> $DIR/existential-types-with-cycle-error.rs:1:1
+   |
+LL | / #![feature(existential_type)]
+LL | |
+LL | | existential type Foo: Fn() -> Foo;
+LL | |
+...  |
+LL | |
+LL | | }
+   | |_^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0391`.
diff --git a/src/test/ui/existential_types/existential-types-with-cycle-error2.rs b/src/test/ui/existential_types/existential-types-with-cycle-error2.rs
new file mode 100644
index 00000000000..29410309ef2
--- /dev/null
+++ b/src/test/ui/existential_types/existential-types-with-cycle-error2.rs
@@ -0,0 +1,16 @@
+#![feature(existential_type)]
+
+pub trait Bar<T> {
+    type Item;
+}
+
+existential type Foo: Bar<Foo, Item = Foo>;
+//~^ ERROR: cycle detected when processing `Foo`
+
+fn crash(x: Foo) -> Foo {
+    x
+}
+
+fn main() {
+
+}
diff --git a/src/test/ui/existential_types/existential-types-with-cycle-error2.stderr b/src/test/ui/existential_types/existential-types-with-cycle-error2.stderr
new file mode 100644
index 00000000000..8c7bf52470a
--- /dev/null
+++ b/src/test/ui/existential_types/existential-types-with-cycle-error2.stderr
@@ -0,0 +1,30 @@
+error[E0391]: cycle detected when processing `Foo`
+  --> $DIR/existential-types-with-cycle-error2.rs:7:1
+   |
+LL | existential type Foo: Bar<Foo, Item = Foo>;
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: ...which requires processing `crash`...
+  --> $DIR/existential-types-with-cycle-error2.rs:10:25
+   |
+LL |   fn crash(x: Foo) -> Foo {
+   |  _________________________^
+LL | |     x
+LL | | }
+   | |_^
+   = note: ...which again requires processing `Foo`, completing the cycle
+note: cycle used when collecting item types in top-level module
+  --> $DIR/existential-types-with-cycle-error2.rs:1:1
+   |
+LL | / #![feature(existential_type)]
+LL | |
+LL | | pub trait Bar<T> {
+LL | |     type Item;
+...  |
+LL | |
+LL | | }
+   | |_^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0391`.
-- 
2.44.0