add more tests for json_pretty

expression/builtin_json_test.go

@@ -995,3 +995,44 @@ func (s *testEvaluatorSuite) TestJSONStorageSize(c *C) {
 		}
 	}
 }
+
+func (s *testEvaluatorSuite) TestJSONPretty(c *C) {
+	fc := funcs[ast.JSONPretty]
+	tbl := []struct {
+		input    []interface{}
+		expected interface{}
+		success  bool
+	}{
+		// Tests scalar arguments
+		{[]interface{}{nil}, nil, true},
+		{[]interface{}{`true`}, "true", true},
+		{[]interface{}{`false`}, "false", true},
+		{[]interface{}{`2223`}, "2223", true},
+		// Tests simple json
+		{[]interface{}{`{"a":1}`}, "{\n  \"a\": 1\n}", true},
+		{[]interface{}{`[1]`}, "[\n  1\n]", true},
+		// Test complex json
+		{[]interface{}{`{"a":1,"b":[{"d":1},{"e":2},{"f":3}],"c":"eee"}`}, "{\n  \"a\": 1,\n  \"b\": [\n    {\n      \"d\": 1\n    },\n    {\n      \"e\": 2\n    },\n    {\n      \"f\": 3\n    }\n  ],\n  \"c\": \"eee\"\n}", true},
+		{[]interface{}{`{"a":1,"b":"qwe","c":[1,2,3,"123",null],"d":{"d1":1,"d2":2}}`}, "{\n  \"a\": 1,\n  \"b\": \"qwe\",\n  \"c\": [\n    1,\n    2,\n    3,\n    \"123\",\n    null\n  ],\n  \"d\": {\n    \"d1\": 1,\n    \"d2\": 2\n  }\n}", true},
+		// Tests invalid json data
+		{[]interface{}{`{1}`}, nil, false},
+		{[]interface{}{`[1,3,4,5]]`}, nil, false},
+	}
+	for _, t := range tbl {
+		args := types.MakeDatums(t.input...)
+		f, err := fc.getFunction(s.ctx, s.datumsToConstants(args))
+		c.Assert(err, IsNil)
+		d, err := evalBuiltinFunc(f, chunk.Row{})
+		if t.success {
+			c.Assert(err, IsNil)
+
+			if t.expected == nil {
+				c.Assert(d.IsNull(), IsTrue)
+			} else {
+				c.Assert(d.GetString(), Equals, t.expected.(string))
+			}
+		} else {
+			c.Assert(err, NotNil)
+		}
+	}
+}