1 files changed, 34 insertions, 0 deletions

diff --git a/crates/ra_assists/src/doc_tests.rs b/crates/ra_assists/src/doc_tests.rs
new file mode 100644
index 000000000..6e1e3de84
--- /dev/null
+++ b/crates/ra_assists/src/doc_tests.rs
@@ -0,0 +1,34 @@
+//! Each assist definition has a special comment, which specifies docs and
+//! example.
+//!
+//! We collect all the example and write the as tests in this module.
+
+mod generated;
+
+use hir::mock::MockDatabase;
+use ra_db::FileRange;
+use test_utils::{assert_eq_text, extract_range_or_offset};
+
+fn check(assist_id: &str, before: &str, after: &str) {
+    let (selection, before) = extract_range_or_offset(before);
+    let (db, _source_root, file_id) = MockDatabase::with_single_file(&before);
+    let frange = FileRange { file_id, range: selection.into() };
+
+    let (_assist_id, action) = crate::assists(&db, frange)
+        .into_iter()
+        .find(|(id, _)| id.id.0 == assist_id)
+        .unwrap_or_else(|| {
+            panic!(
+                "\n\nAssist is not applicable: {}\nAvailable assists: {}",
+                assist_id,
+                crate::assists(&db, frange)
+                    .into_iter()
+                    .map(|(id, _)| id.id.0)
+                    .collect::<Vec<_>>()
+                    .join(", ")
+            )
+        });
+
+    let actual = action.edit.apply(&before);
+    assert_eq_text!(after, &actual);
+}