Merge pull request #19 from palfrey/tests-with-return-value

Allow tests with return values

serial_test/src/lib.rs

@@ -28,8 +28,7 @@ lazy_static! {
         Arc::new(RwLock::new(HashMap::new()));
 }
 
-#[doc(hidden)]
-pub fn serial_core(name: &str, function: fn()) {
+fn check_new_key(name: &str) {
     // Check if a new key is needed. Just need a read lock, which can be done in sync with everyone else
     let new_key = {
         let unlock = LOCKS.read().unwrap();
@@ -43,6 +42,22 @@ pub fn serial_core(name: &str, function: fn()) {
             .deref_mut()
             .insert(name.to_string(), ReentrantMutex::new(()));
     }
+}
+
+#[doc(hidden)]
+pub fn serial_core_with_return<E>(name: &str, function: fn() -> Result<(), E>) -> Result<(), E> {
+    check_new_key(name);
+
+    let unlock = LOCKS.read().unwrap();
+    // _guard needs to be named to avoid being instant dropped
+    let _guard = unlock.deref()[name].lock();
+    function()
+}
+
+#[doc(hidden)]
+pub fn serial_core(name: &str, function: fn()) {
+    check_new_key(name);
+
     let unlock = LOCKS.read().unwrap();
     // _guard needs to be named to avoid being instant dropped
     let _guard = unlock.deref()[name].lock();

serial_test_derive/src/lib.rs

@@ -7,6 +7,7 @@ use proc_macro::TokenStream;
 use proc_macro2::TokenTree;
 use quote::quote;
 use syn;
+use std::ops::Deref;
 
 /// Allows for the creation of serialised Rust tests
 /// ````
@@ -78,6 +79,12 @@ fn serial_core(
     };
     let ast: syn::ItemFn = syn::parse2(input).unwrap();
     let name = ast.sig.ident;
+    let return_type = match ast.sig.output {
+        syn::ReturnType::Default => None,
+        syn::ReturnType::Type(_rarrow, ref box_type) => {
+            Some(box_type.deref())
+        }
+    };
     let block = ast.block;
     let attrs: Vec<syn::Attribute> = ast
         .attrs
@@ -96,13 +103,25 @@ fn serial_core(
             }
         })
         .collect();
-    let gen = quote! {
-        #(#attrs)
-        *
-        fn #name () {
-            serial_test::serial_core(#key, || {
-                #block
-            });
+    let gen = if let Some(ret) = return_type {
+        quote! {
+            #(#attrs)
+            *
+            fn #name () -> #ret {
+                serial_test::serial_core_with_return(#key, || {
+                    #block
+                })
+            }
+        }
+    } else {
+        quote! {
+            #(#attrs)
+            *
+            fn #name () {
+                serial_test::serial_core(#key, || {
+                    #block
+                });
+            }
         }
     };
     return gen.into();

serial_test_test/src/lib.rs

@@ -76,4 +76,10 @@ mod tests {
         init();
         panic!("Testing panic");
     }
+
+    #[test]
+    #[serial]
+    fn test_can_return() -> Result<(), ()> {
+        Ok(())
+    }
 }