Reorganize tests

crates/libeditor/src/test_utils.rs

@@ -0,0 +1,20 @@
+use libsyntax2::{File, TextUnit};
+pub use _test_utils::*;
+use ActionResult;
+
+pub fn check_action<F: Fn(&File, TextUnit) -> Option<ActionResult>> (
+    before: &str,
+    after: &str,
+    f: F,
+) {
+    let (before_cursor_pos, before) = extract_offset(before);
+    let file = File::parse(&before);
+    let result = f(&file, before_cursor_pos).expect("code action is not applicable");
+    let actual = result.edit.apply(&before);
+    let actual_cursor_pos = match result.cursor_position {
+        None => result.edit.apply_to_offset(before_cursor_pos).unwrap(),
+        Some(off) => off,
+    };
+    let actual = add_cursor(&actual, actual_cursor_pos);
+    assert_eq_text!(after, &actual);
+}