Change test to not rely on trait inference

Author: theotherphil

crates/ra_ide_api/src/diagnostics.rs

@@ -285,34 +285,29 @@ fn div(x: i32, y: i32) -> Result<i32, String> {
     fn test_wrap_return_type_handles_generic_functions() {
         let before = r#"
             //- /main.rs
-            use std::{default::Default, result::Result::{self, Ok, Err}};
+            use std::result::Result::{self, Ok, Err};
 
-            fn div<T: Default, i32>(x: i32) -> Result<T, i32> {
+            fn div<T>(x: T) -> Result<T, i32> {
                 if x == 0 {
                     return Err(7);
                 }
-                T::default()
+                x
             }
 
             //- /std/lib.rs
             pub mod result {
                 pub enum Result<T, E> { Ok(T), Err(E) }
             }
-            pub mod default {
-                pub trait Default {
-                    fn default() -> Self;
-                }
-            }
         "#;
 // The formatting here is a bit odd due to how the parse_fixture function works in test_utils -
 // it strips empty lines and leading whitespace. The important part of this test is that the final
-// `x / y` expr is now wrapped in `Ok(..)`
-        let after = r#"use std::{default::Default, result::Result::{self, Ok, Err}};
-fn div<T: Default>(x: i32) -> Result<T, i32> {
+// expr is now wrapped in `Ok(..)`
+        let after = r#"use std::result::Result::{self, Ok, Err};
+fn div<T>(x: T) -> Result<T, i32> {
     if x == 0 {
         return Err(7);
     }
-    Ok(T::default())
+    Ok(x)
 }
 "#;
         check_apply_diagnostic_fix_for_target_file("/main.rs", before, after);