import: refactor, move engine::tests::new_engine into test_helpers

Let other tests using the same pattern reuse this function.

src/import/engine.rs

@@ -376,18 +376,10 @@ mod tests {
 
     use crate::raftstore::store::RegionSnapshot;
     use crate::storage::mvcc::MvccReader;
+    use crate::import::test_helpers::new_engine;
     use engine::rocks::util::security::encrypted_env_from_cipher_file;
     use tikv_util::file::file_exists;
 
-    fn new_engine() -> (TempDir, Engine) {
-        let dir = TempDir::new("test_import_engine").unwrap();
-        let uuid = Uuid::new_v4();
-        let db_cfg = DbConfig::default();
-        let security_cfg = SecurityConfig::default();
-        let engine = Engine::new(dir.path(), uuid, db_cfg, security_cfg).unwrap();
-        (dir, engine)
-    }
-
     fn new_write_batch(n: u8, ts: u64) -> WriteBatch {
         let mut wb = WriteBatch::new();
         for i in 0..n {
@@ -407,7 +399,7 @@ mod tests {
 
     #[test]
     fn test_write() {
-        let (_dir, engine) = new_engine();
+        let (_dir, engine) = new_engine("test_write");
 
         let n = 10;
         let commit_ts = 10;
@@ -517,7 +509,7 @@ mod tests {
 
     #[test]
     fn test_approximate_ranges() {
-        let (_dir, engine) = new_engine();
+        let (_dir, engine) = new_engine("test_approximate_ranges");
 
         let num_files = 3;
         let num_entries = 3;

src/import/prepare.rs

@@ -323,12 +323,8 @@ mod tests {
     use crate::import::test_helpers::*;
 
     use engine::rocks::Writable;
-    use tempdir::TempDir;
-    use uuid::Uuid;
 
-    use crate::config::DbConfig;
     use crate::storage::types::Key;
-    use tikv_util::security::SecurityConfig;
 
     fn new_encoded_key(k: &[u8]) -> Vec<u8> {
         if k.is_empty() {
@@ -340,11 +336,8 @@ mod tests {
 
     #[test]
     fn test_prepare_job() {
-        let dir = TempDir::new("test_import_prepare_job").unwrap();
-        let uuid = Uuid::new_v4();
-        let db_cfg = DbConfig::default();
-        let security_cfg = SecurityConfig::default();
-        let engine = Arc::new(Engine::new(dir.path(), uuid, db_cfg, security_cfg).unwrap());
+        let (_dir, engine) = new_engine("test_import_prepare_job");
+        let engine = Arc::new(engine);
 
         // Generate entries to prepare.
         let (n, m) = (4, 4);

src/import/stream.rs

@@ -199,9 +199,7 @@ mod tests {
     use engine::rocks::{DBIterator, DBOptions, ReadOptions, Writable, DB};
     use tempdir::TempDir;
 
-    use crate::config::DbConfig;
     use crate::storage::types::Key;
-    use tikv_util::security::SecurityConfig;
 
     fn open_db<P: AsRef<Path>>(path: P) -> Arc<DB> {
         let path = path.as_ref().to_str().unwrap();
@@ -363,11 +361,8 @@ mod tests {
 
     #[test]
     fn test_sst_file_stream() {
-        let dir = TempDir::new("test_import_sst_file_stream").unwrap();
-        let uuid = Uuid::new_v4();
-        let db_cfg = DbConfig::default();
-        let security_cfg = SecurityConfig::default();
-        let engine = Arc::new(Engine::new(dir.path(), uuid, db_cfg, security_cfg).unwrap());
+        let (_dir, engine) = new_engine("test_import_sst_file_stream");
+        let engine = Arc::new(engine);
 
         for i in 0..16 {
             let k = Key::from_raw(&[i]).append_ts(0);

src/import/test_helpers.rs

@@ -9,12 +9,16 @@ use crc::crc32::{self, Hasher32};
 use kvproto::import_sstpb::*;
 use kvproto::kvrpcpb::*;
 use kvproto::metapb::*;
+use tempdir::TempDir;
 use uuid::Uuid;
 
+use crate::config::DbConfig;
+use crate::import::engine::Engine;
 use crate::pd::RegionInfo;
 use crate::raftstore::store::keys;
 use engine::rocks::{ColumnFamilyOptions, EnvOptions, SstFileWriter, DB};
 use tikv_util::collections::HashMap;
+use tikv_util::security::SecurityConfig;
 
 use super::client::*;
 use super::common::*;
@@ -63,6 +67,16 @@ pub fn read_sst_file<P: AsRef<Path>>(path: P, range: (u8, u8)) -> (SSTMeta, Vec<
     (meta, data)
 }
 
+/// Creates a new, empty engine in a temporary directory.
+pub fn new_engine(name: &str) -> (TempDir, Engine) {
+    let dir = TempDir::new(name).unwrap();
+    let uuid = Uuid::new_v4();
+    let db_cfg = DbConfig::default();
+    let security_cfg = SecurityConfig::default();
+    let engine = Engine::new(dir.path(), uuid, db_cfg, security_cfg).unwrap();
+    (dir, engine)
+}
+
 #[derive(Clone)]
 pub struct MockClient {
     counter: Arc<AtomicUsize>,