refactor(test): Move test_empty_expr.py into test_treegen.py

Author: MarcellPerger1

test/test_cstgen/.snapshots/test_empty_expr.txt

@@ -118,5 +118,28 @@ def test_getitem__issue_09(self):
         self.assertMatchesSnapshot(node, 'after_string')
 
 
+class TestEmptyExpr(CommonTestCase):
+    def test_error_empty_assign_source(self):
+        t = Tokenizer('let a= ;').tokenize()
+        with self.assertRaises(LocatedCstError) as err:
+            CstGen(t).parse()
+        self.assertBetweenIncl(5, 7, err.exception.region.start)
+        self.assertBetweenIncl(7, 8, err.exception.region.end)
+        self.assertContains(str(err.exception), "semi")
+
+    def test_error_empty_condition(self):
+        t = Tokenizer('if {x();}').tokenize()
+        with self.assertRaises(LocatedCstError) as err:
+            CstGen(t).parse()
+        self.assertBetweenIncl(0, 3, err.exception.region.start)
+        self.assertBetweenIncl(2, 4, err.exception.region.end)
+        self.assertContains(str(err.exception), "brace")
+
+    def test_empty_expr_issue_04(self):
+        t = Tokenizer('let a=9;;').tokenize()
+        node = CstGen(t).parse()
+        self.assertMatchesSnapshot(node)
+
+
 if __name__ == '__main__':
     unittest.main()