Add test of #[from] on optional source

dtolnay · Aug 28, 2021 · 6159aba · 6159aba
1 parent b087faf
commit 6159aba
Showing 1 changed file with 23 additions and 0 deletions.
diff --git a/tests/test_from.rs b/tests/test_from.rs
@@ -14,10 +14,21 @@ pub struct ErrorStruct {
     source: io::Error,
 }
 
+#[derive(Error, Debug)]
+#[error("...")]
+pub struct ErrorStructOptional {
+    #[from]
+    source: Option<io::Error>,
+}
+
 #[derive(Error, Debug)]
 #[error("...")]
 pub struct ErrorTuple(#[from] io::Error);
 
+#[derive(Error, Debug)]
+#[error("...")]
+pub struct ErrorTupleOptional(#[from] Option<io::Error>);
+
 #[derive(Error, Debug)]
 #[error("...")]
 pub enum ErrorEnum {
@@ -27,6 +38,15 @@ pub enum ErrorEnum {
     },
 }
 
+#[derive(Error, Debug)]
+#[error("...")]
+pub enum ErrorEnumOptional {
+    Test {
+        #[from]
+        source: Option<io::Error>,
+    },
+}
+
 #[derive(Error, Debug)]
 #[error("...")]
 pub enum Many {
@@ -39,7 +59,10 @@ fn assert_impl<T: From<io::Error>>() {}
 #[test]
 fn test_from() {
     assert_impl::<ErrorStruct>();
+    assert_impl::<ErrorStructOptional>();
     assert_impl::<ErrorTuple>();
+    assert_impl::<ErrorTupleOptional>();
     assert_impl::<ErrorEnum>();
+    assert_impl::<ErrorEnumOptional>();
     assert_impl::<Many>();
 }