Merge pull request #5 from database-pizza/fix/json-text-contract

test(json): pin the TEXT + JSON1 contract over the pg wire

pkg/pgserver/json_contract_test.go

@@ -0,0 +1,91 @@
+package pgserver
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+)
+
+// jsonErrorField extracts a named field from an ErrorResponse.
+func jsonErrorField(t *testing.T, msg *Message, want byte) string {
+	t.Helper()
+	if msg == nil || msg.Type != MsgErrorResponse {
+		t.Fatalf("message type = %v, want ErrorResponse", msg)
+	}
+	data := msg.Data
+	for i := 0; i < len(data); {
+		if data[i] == 0 {
+			break
+		}
+		field := data[i]
+		i++
+		end := bytes.IndexByte(data[i:], 0)
+		if end < 0 {
+			break
+		}
+		value := string(data[i : i+end])
+		if field == want {
+			return value
+		}
+		i += end + 1
+	}
+	return ""
+}
+
+// The supported JSON contract is TEXT storage plus the JSON1 function surface.
+// JSON/JSONB type names are accepted as text-affinity aliases; there is no
+// native binary jsonb type or ->> operator.
+func TestJSONTextContractOverSimpleQuery(t *testing.T) {
+	c, client := newDataConnection(t)
+	runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte("CREATE TABLE settings (id INTEGER PRIMARY KEY, body TEXT)"), 0)})
+
+	runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte(`INSERT INTO settings (id, body) VALUES (1, '{"theme":"dark","widgets":[1,2]}')`), 0)})
+
+	msgs := runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte(`SELECT json_extract(body, '$.theme'), json_type(body), json_valid(body) FROM settings WHERE id = 1`), 0)})
+	values := dataRowValues(t, msgs[1])
+	if len(values) != 3 || values[0] != "dark" || values[1] != "object" || values[2] != "1" {
+		t.Fatalf("json round trip = %v, want [dark object 1]", values)
+	}
+
+	// Partial update through json_set, without rewriting the whole document.
+	runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte(`UPDATE settings SET body = json_set(body, '$.theme', 'light') WHERE id = 1`), 0)})
+	msgs = runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte(`SELECT json_extract(body, '$.theme'), json_extract(body, '$.widgets[1]') FROM settings WHERE id = 1`), 0)})
+	values = dataRowValues(t, msgs[1])
+	if len(values) != 2 || values[0] != "light" || values[1] != "2" {
+		t.Fatalf("json partial update = %v, want [light 2]", values)
+	}
+
+	// JSON and JSONB column type names are text-affinity aliases.
+	runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte("CREATE TABLE docs (id INTEGER PRIMARY KEY, body JSON)"), 0)})
+	runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte(`INSERT INTO docs (id, body) VALUES (1, '{"a":1}')`), 0)})
+	msgs = runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte(`SELECT json_extract(body, '$.a') FROM docs`), 0)})
+	if got := dataRowValues(t, msgs[1]); len(got) != 1 || got[0] != "1" {
+		t.Fatalf("JSON column extract = %v, want [1]", got)
+	}
+}
+
+func TestJSONInvalidInputOverSimpleQuery(t *testing.T) {
+	c, client := newDataConnection(t)
+
+	msgs := runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte(`SELECT json_extract('not json', '$.a')`), 0)})
+	if len(msgs) != 2 || msgs[0].Type != MsgErrorResponse {
+		t.Fatalf("expected ErrorResponse+ReadyForQuery, got %v", msgs)
+	}
+	if msg := jsonErrorField(t, msgs[0], ErrorFieldMessage); !strings.Contains(msg, "malformed JSON") {
+		t.Fatalf("error message = %q, want a malformed-JSON error", msg)
+	}
+
+	// json_valid is the non-throwing way to probe a value.
+	msgs = runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte(`SELECT json_valid('not json')`), 0)})
+	if got := dataRowValues(t, msgs[1]); len(got) != 1 || got[0] != "0" {
+		t.Fatalf("json_valid = %v, want [0]", got)
+	}
+}
+
+func TestJSONArrowOperatorUnsupported(t *testing.T) {
+	c, client := newDataConnection(t)
+	msgs := runQuery(t, c, client, &Message{Type: MsgQuery, Data: append([]byte(`SELECT '{"a":1}' -> '$.a'`), 0)})
+	if len(msgs) == 0 || msgs[0].Type != MsgErrorResponse {
+		t.Fatalf("expected a parse error for the -> operator, got %v", msgs)
+	}
+}