Add concurrent query test

db/db_test.go

@@ -658,6 +658,45 @@ func Test_WriteOnQueryInMemDatabase(t *testing.T) {
 	}
 }
 
+func Test_ConcurrentQueriesInMemory(t *testing.T) {
+	db := mustCreateInMemoryDatabase()
+	defer db.Close()
+
+	r, err := db.ExecuteStringStmt(`CREATE TABLE foo (id INTEGER NOT NULL PRIMARY KEY, name TEXT)`)
+	if err != nil {
+		t.Fatalf("failed to create table: %s", err.Error())
+	}
+	if exp, got := `[{}]`, asJSON(r); exp != got {
+		t.Fatalf("unexpected results for query\nexp: %s\ngot: %s", exp, got)
+	}
+
+	for i := 0; i < 5000; i++ {
+		r, err = db.ExecuteStringStmt(`INSERT INTO foo(name) VALUES("fiona")`)
+		if err != nil {
+			t.Fatalf("failed to insert record: %s", err.Error())
+		}
+		if exp, got := fmt.Sprintf(`[{"last_insert_id":%d,"rows_affected":1}]`, i+1), asJSON(r); exp != got {
+			t.Fatalf("unexpected results for query\nexp: %s\ngot: %s", exp, got)
+		}
+	}
+
+	var wg sync.WaitGroup
+	for i := 0; i < 32; i++ {
+		go func() {
+			wg.Add(1)
+			defer wg.Done()
+			ro, err := db.QueryStringStmt(`SELECT COUNT(*) FROM foo`)
+			if err != nil {
+				t.Fatalf("failed to query table: %s", err.Error())
+			}
+			if exp, got := `[{"columns":["COUNT(*)"],"types":[""],"values":[[5000]]}]`, asJSON(ro); exp != got {
+				t.Fatalf("unexpected results for query\nexp: %s\ngot: %s", exp, got)
+			}
+		}()
+	}
+	wg.Wait()
+}
+
 func Test_SimpleParameterizedStatements(t *testing.T) {
 	db, path := mustCreateDatabase()
 	defer db.Close()