Make more tests deterministic

This commit fixes a lot of randomly failing tests by adding `ORDER BY`
clauses to some queries. It also prevents concurrently creating an
`INDEX` for the same table (which results in a deadlock in postgres
sometimes).

(This was tested by running `diesel_tests` in a loop until 100
continuous runs passed)

diesel_tests/tests/alias.rs

@@ -20,6 +20,7 @@ fn selecting_basic_data() {
             user_alias.field(users::name),
             user_alias.field(users::hair_color),
         ))
+        .order(user_alias.field(users::name))
         .load(connection)
         .unwrap();
 

diesel_tests/tests/boxed_queries.rs

@@ -37,7 +37,7 @@ fn boxed_queries_can_differ_conditionally() {
     }
 
     let source = |query| match query {
-        Query::All => users::table.into_boxed(),
+        Query::All => users::table.order(users::name.desc()).into_boxed(),
         Query::Ordered => users::table.order(users::name.desc()).into_boxed(),
         Query::One => users::table
             .filter(users::name.ne("jim"))
@@ -51,7 +51,7 @@ fn boxed_queries_can_differ_conditionally() {
     let jim = find_user_by_name("Jim", connection);
 
     let all = source(Query::All).load(connection);
-    let expected_data = vec![sean.clone(), tess.clone(), jim.clone()];
+    let expected_data = vec![tess.clone(), sean.clone(), jim.clone()];
     assert_eq!(Ok(expected_data), all);
 
     let ordered = source(Query::Ordered).load(connection);
@@ -69,6 +69,7 @@ fn boxed_queries_implement_select_dsl() {
     let data = users::table
         .into_boxed()
         .select(users::name)
+        .order(users::name)
         .load::<String>(connection);
     assert_eq!(Ok(vec!["Sean".into(), "Tess".into()]), data);
 }
@@ -92,7 +93,11 @@ fn boxed_queries_implement_filter_dsl() {
 #[test]
 fn boxed_queries_implement_limit_dsl() {
     let connection = &mut connection_with_sean_and_tess_in_users_table();
-    let data = users::table.into_boxed().limit(1).load(connection);
+    let data = users::table
+        .into_boxed()
+        .limit(1)
+        .order(users::id)
+        .load(connection);
     let expected_data = vec![find_user_by_name("Sean", connection)];
     assert_eq!(Ok(expected_data), data);
 }
@@ -104,6 +109,7 @@ fn boxed_queries_implement_offset_dsl() {
         .into_boxed()
         .limit(1)
         .offset(1)
+        .order(users::id)
         .load(connection);
     let expected_data = vec![find_user_by_name("Tess", connection)];
     assert_eq!(Ok(expected_data), data);
@@ -154,6 +160,7 @@ fn boxed_queries_implement_or_filter() {
         .into_boxed()
         .filter(users::name.eq("Sean"))
         .or_filter(users::name.eq("Tess"))
+        .order(users::name)
         .load(connection);
     let expected = vec![
         find_user_by_name("Sean", connection),

diesel_tests/tests/combination.rs

@@ -13,7 +13,7 @@ fn union() {
         NewUser::new("Jim", None),
     ];
     insert_into(users).values(&data).execute(conn).unwrap();
-    let data = users.load::<User>(conn).unwrap();
+    let data = users.order(id).load::<User>(conn).unwrap();
     let sean = &data[0];
     let tess = &data[1];
     let jim = &data[2];
@@ -43,7 +43,7 @@ fn union_all() {
         NewUser::new("Jim", None),
     ];
     insert_into(users).values(&data).execute(conn).unwrap();
-    let data = users.load::<User>(conn).unwrap();
+    let data = users.order(id).load::<User>(conn).unwrap();
     let sean = &data[0];
     let tess = &data[1];
     let jim = &data[2];
@@ -75,10 +75,10 @@ fn intersect() {
         NewUser::new("Jim", None),
     ];
     insert_into(users).values(&data).execute(conn).unwrap();
-    let data = users.load::<User>(conn).unwrap();
-    let _sean = &data[0];
-    let tess = &data[1];
-    let _jim = &data[2];
+    let data = users.order(name).load::<User>(conn).unwrap();
+    let _sean = &data[1];
+    let tess = &data[2];
+    let _jim = &data[0];
 
     let expected_data = vec![User::new(tess.id, "Tess")];
     let data: Vec<_> = users
@@ -171,6 +171,7 @@ fn as_subquery_for_eq_in() {
     let out = posts::table
         .filter(posts::user_id.eq_any(subquery))
         .select(posts::title)
+        .order_by(posts::title)
         .load::<String>(conn)
         .unwrap();
 

diesel_tests/tests/deserialization.rs

@@ -22,11 +22,17 @@ fn generated_queryable_allows_lifetimes() {
     };
     assert_eq!(
         Ok(expected_user),
-        users.select((id, name)).first(connection)
+        users.select((id, name)).order(id).first(connection)
     );
     assert_eq!(
-        users.select((id, name)).first::<CowUser<'_>>(connection),
-        users.select(CowUser::as_select()).first(connection)
+        users
+            .select((id, name))
+            .order(id)
+            .first::<CowUser<'_>>(connection),
+        users
+            .select(CowUser::as_select())
+            .order(id)
+            .first(connection)
     );
 }
 

diesel_tests/tests/distinct.rs

@@ -178,7 +178,7 @@ fn distinct_of_multiple_columns() {
         .execute(&mut connection)
         .unwrap();
     let posts = posts::table
-        .order(posts::id)
+        .order(posts::title)
         .load::<Post>(&mut connection)
         .unwrap();
 

diesel_tests/tests/expressions/mod.rs

@@ -238,6 +238,7 @@ fn function_with_multiple_arguments() {
     let expected_data = vec!["black".to_string(), "Tess".to_string()];
     let data = users
         .select(coalesce(hair_color, name))
+        .order(id)
         .load::<String>(connection);
 
     assert_eq!(Ok(expected_data), data);

diesel_tests/tests/expressions/ops.rs

@@ -8,11 +8,11 @@ fn adding_literal_to_column() {
     let connection = &mut connection_with_sean_and_tess_in_users_table();
 
     let expected_data = vec![2, 3];
-    let data = users.select(id + 1).load(connection);
+    let data = users.select(id + 1).order(id).load(connection);
     assert_eq!(Ok(expected_data), data);
 
     let expected_data = vec![3, 4];
-    let data = users.select(id + 2).load(connection);
+    let data = users.select(id + 2).order(id).load(connection);
     assert_eq!(Ok(expected_data), data);
 }
 
@@ -36,7 +36,7 @@ fn adding_column_to_column() {
     let connection = &mut connection_with_sean_and_tess_in_users_table();
 
     let expected_data = vec![2, 4];
-    let data = users.select(id + id).load(connection);
+    let data = users.select(id + id).order(id).load(connection);
     assert_eq!(Ok(expected_data), data);
 }
 
@@ -47,7 +47,7 @@ fn adding_multiple_times() {
     let connection = &mut connection_with_sean_and_tess_in_users_table();
 
     let expected_data = vec![4, 5];
-    let data = users.select(id + 1 + 2).load(connection);
+    let data = users.select(id + 1 + 2).order(id).load(connection);
     assert_eq!(Ok(expected_data), data);
 }
 
@@ -58,7 +58,7 @@ fn subtracting_literal_from_column() {
     let connection = &mut connection_with_sean_and_tess_in_users_table();
 
     let expected_data = vec![0, 1];
-    let data = users.select(id - 1).load(connection);
+    let data = users.select(id - 1).order(id).load(connection);
     assert_eq!(Ok(expected_data), data);
 }
 
@@ -69,7 +69,7 @@ fn adding_then_subtracting() {
     let connection = &mut connection_with_sean_and_tess_in_users_table();
 
     let expected_data = vec![2, 3];
-    let data = users.select(id + 2 - 1).load(connection);
+    let data = users.select(id + 2 - 1).order(id).load(connection);
     assert_eq!(Ok(expected_data), data);
 }
 
@@ -80,7 +80,7 @@ fn multiplying_column() {
     let connection = &mut connection_with_sean_and_tess_in_users_table();
 
     let expected_data = vec![3, 6];
-    let data = users.select(id * 3).load(connection);
+    let data = users.select(id * 3).order(id).load(connection);
     assert_eq!(Ok(expected_data), data);
 }
 
@@ -91,7 +91,7 @@ fn dividing_column() {
     let connection = &mut connection_with_sean_and_tess_in_users_table();
 
     let expected_data = vec![0, 1];
-    let data = users.select(id / 2).load(connection);
+    let data = users.select(id / 2).order(id).load(connection);
     assert_eq!(Ok(expected_data), data);
 }
 
@@ -192,7 +192,7 @@ fn mix_and_match_all_numeric_ops() {
     .unwrap();
 
     let expected_data = vec![4, 6, 7, 9];
-    let data = users.select(id * 3 / 2 + 4 - 1).load(connection);
+    let data = users.select(id * 3 / 2 + 4 - 1).order(id).load(connection);
     assert_eq!(Ok(expected_data), data);
 }
 

diesel_tests/tests/insert_from_select.rs

@@ -11,7 +11,10 @@ fn insert_from_table() {
         .execute(conn)
         .unwrap();
 
-    let data = posts.select((user_id, title, body)).load(conn);
+    let data = posts
+        .select((user_id, title, body))
+        .order(user_id)
+        .load(conn);
     let expected = vec![
         (1, String::from("Sean"), None::<String>),
         (2, String::from("Tess"), None),
@@ -29,7 +32,10 @@ fn insert_from_table_reference() {
         .execute(conn)
         .unwrap();
 
-    let data = posts.select((user_id, title, body)).load(conn);
+    let data = posts
+        .select((user_id, title, body))
+        .order(user_id)
+        .load(conn);
     let expected = vec![
         (1, String::from("Sean"), None::<String>),
         (2, String::from("Tess"), None),
@@ -50,7 +56,11 @@ fn insert_from_select() {
         .execute(conn)
         .unwrap();
 
-    let data = posts.select(title).load::<String>(conn).unwrap();
+    let data = posts
+        .select(title)
+        .order(title)
+        .load::<String>(conn)
+        .unwrap();
     let expected = vec!["Sean says hi", "Tess says hi"];
     assert_eq!(expected, data);
 }
@@ -68,7 +78,11 @@ fn insert_from_select_reference() {
         .execute(conn)
         .unwrap();
 
-    let data = posts.select(title).load::<String>(conn).unwrap();
+    let data = posts
+        .select(title)
+        .order(title)
+        .load::<String>(conn)
+        .unwrap();
     let expected = vec!["Sean says hi", "Tess says hi"];
     assert_eq!(expected, data);
 }
@@ -87,7 +101,11 @@ fn insert_from_boxed() {
         .execute(conn)
         .unwrap();
 
-    let data = posts.select(title).load::<String>(conn).unwrap();
+    let data = posts
+        .select(title)
+        .order(title)
+        .load::<String>(conn)
+        .unwrap();
     let expected = vec!["Sean says hi", "Tess says hi"];
     assert_eq!(expected, data);
 }
@@ -105,7 +123,11 @@ fn insert_from_boxed_reference() {
         .execute(conn)
         .unwrap();
 
-    let data = posts.select(title).load::<String>(conn).unwrap();
+    let data = posts
+        .select(title)
+        .order(title)
+        .load::<String>(conn)
+        .unwrap();
     let expected = vec!["Sean says hi", "Tess says hi"];
     assert_eq!(expected, data);
 }
@@ -255,7 +277,11 @@ fn on_conflict_do_nothing_with_select() {
         assert_eq!(0, inserted_rows);
     }
 
-    let data = posts.select(title).load::<String>(conn).unwrap();
+    let data = posts
+        .select(title)
+        .order(title)
+        .load::<String>(conn)
+        .unwrap();
     let expected = vec!["Sean says hi", "Tess says hi"];
     assert_eq!(expected, data);
 }

diesel_tests/tests/joins.rs

@@ -20,7 +20,7 @@ fn belongs_to() {
     let tess_post = Post::new(2, 2, "World", None);
 
     let expected_data = vec![(seans_post, sean), (tess_post, tess)];
-    let source = posts::table.inner_join(users::table);
+    let source = posts::table.inner_join(users::table).order(posts::id);
     let actual_data: Vec<_> = source.load(connection).unwrap();
 
     assert_eq!(expected_data, actual_data);
@@ -40,8 +40,8 @@ fn select_single_from_join() {
     .unwrap();
 
     let source = posts::table.inner_join(users::table);
-    let select_name = source.select(users::name);
-    let select_title = source.select(posts::title);
+    let select_name = source.select(users::name).order(users::name);
+    let select_title = source.select(posts::title).order(posts::title);
 
     let expected_names = vec!["Sean".to_string(), "Tess".to_string()];
     let actual_names: Vec<String> = select_name.load(connection).unwrap();
@@ -75,7 +75,7 @@ fn select_multiple_from_join() {
         ("Sean".to_string(), "Hello".to_string()),
         ("Tess".to_string(), "World".to_string()),
     ];
-    let actual_data: Vec<_> = source.load(connection).unwrap();
+    let actual_data: Vec<_> = source.order(users::name).load(connection).unwrap();
 
     assert_eq!(expected_data, actual_data);
 }
@@ -102,7 +102,7 @@ fn join_boxed_query() {
         ("Sean".to_string(), "Hello".to_string()),
         ("Tess".to_string(), "World".to_string()),
     ];
-    let actual_data: Vec<_> = source.load(connection).unwrap();
+    let actual_data: Vec<_> = source.order(users::name).load(connection).unwrap();
 
     assert_eq!(expected_data, actual_data);
 }

diesel_tests/tests/order.rs

@@ -12,10 +12,10 @@ fn order_by_column() {
         NewUser::new("Jim", None),
     ];
     insert_into(users).values(&data).execute(conn).unwrap();
-    let data = users.load::<User>(conn).unwrap();
-    let sean = &data[0];
-    let tess = &data[1];
-    let jim = &data[2];
+    let data = users.order(name).load::<User>(conn).unwrap();
+    let sean = &data[1];
+    let tess = &data[2];
+    let jim = &data[0];
 
     let expected_data = vec![
         User::new(jim.id, "Jim"),