Adding delete_all_documents method for IndexWriter (#133)

src/index.rs

@@ -117,6 +117,12 @@ impl IndexWriter {
         Ok(())
     }
 
+    /// Deletes all documents from the index.
+    fn delete_all_documents(&mut self) -> PyResult<()> {
+        self.inner()?.delete_all_documents().map_err(to_pyerr)?;
+        Ok(())
+    }
+
     /// The opstamp of the last successful commit.
     ///
     /// This is the opstamp the index will rollback to if there is a failure

tests/tantivy_test.py

@@ -488,6 +488,18 @@ class TestClass(object):
 
         assert orig == pickled
 
+    def test_delete_all_documents(self, ram_index):
+        index = ram_index
+        writer = index.writer()
+        writer.delete_all_documents()
+        writer.commit()
+
+        index.reload()
+        query = index.parse_query("sea whale", ["title", "body"])
+        result = index.searcher().search(query, 10)
+
+        assert len(result.hits) == 0
+
 
 class TestUpdateClass(object):
     def test_delete_update(self, ram_index):