Basic support for reading and writing JSON objects.

runtime/vm/json_test.cc

Index: runtime/vm/json_test.cc
===================================================================
--- runtime/vm/json_test.cc	(revision 0)
+++ runtime/vm/json_test.cc	(revision 0)
@@ -0,0 +1,119 @@
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include "platform/assert.h"
+#include "vm/json.h"
+#include "vm/unit_test.h"
+
+namespace dart {
+
+
+TEST_CASE(JSON_ScanJSON) {
+  const char* msg = "{ \"id\": 5, \"command\" : \"Debugger.pause\" }";
+
+  JSONScanner scanner(msg);
+  EXPECT_EQ(scanner.CurrentToken(), JSONScanner::TokenIllegal);
+  scanner.Scan();
+  EXPECT_EQ(scanner.CurrentToken(), JSONScanner::TokenLBrace);
+  scanner.Scan();
+  EXPECT_EQ(scanner.CurrentToken(), JSONScanner::TokenString);
+  EXPECT(scanner.IsStringLiteral("id"));
+  scanner.Scan();
+  EXPECT_EQ(scanner.CurrentToken(), JSONScanner::TokenColon);
+  scanner.Scan();
+  EXPECT_EQ(scanner.CurrentToken(), JSONScanner::TokenInteger);
+  scanner.Scan();
+  EXPECT_EQ(scanner.CurrentToken(), JSONScanner::TokenComma);
+  scanner.Scan();
+  EXPECT_EQ(scanner.CurrentToken(), JSONScanner::TokenString);
+  EXPECT(scanner.IsStringLiteral("command"));
+  scanner.Scan();
+  EXPECT_EQ(scanner.CurrentToken(), JSONScanner::TokenColon);
+  scanner.Scan();
+  EXPECT_EQ(scanner.CurrentToken(), JSONScanner::TokenString);
+  EXPECT(scanner.IsStringLiteral("Debugger.pause"));
+  scanner.Scan();
+  EXPECT_EQ(scanner.CurrentToken(), JSONScanner::TokenRBrace);
+  scanner.Scan();
+  EXPECT_EQ(scanner.CurrentToken(), JSONScanner::TokenEOM);
+}
+
+
+TEST_CASE(JSON_SyntaxError) {
+    const char* jobj = "{ \"id\": 5, "
+                     "  \"command\" : \"Debugger.stop\""  // Missing comma.
+                     "  \"params\" : { "
+                     "    \"url\" : \"blah.dart\", "  // Missing comma.
+                     "    \"line\": 111, "
+                     "  },"
+                     "  \"foo\": \"outer foo\", "
+                     "}";
+  JSONReader reader(jobj);
+  bool found;
+
+  found = reader.Seek("id");
+  EXPECT(found);
+  EXPECT_EQ(reader.Type(), JSONReader::kInteger);
+  found = reader.Seek("params");
+  EXPECT(!found);
+  EXPECT(reader.Error());
+  EXPECT_EQ(reader.Type(), JSONReader::kNone);
+  EXPECT_EQ(0, reader.ValueLen());
+  EXPECT(reader.ValueChars() == NULL);
+}
+
+
+TEST_CASE(JSON_JSONReader) {
+  const char* jobj = "{ \"id\": 5, "
+                     "  \"command\" : \"Debugger.setBreakpoint\","
+                     "  \"params\" : { "
+                     "    \"url\" : \"blah.dart\", "
+                     "    \"foo\" : [null, 1, { }, \"bar\", true, false],"
+                     "    \"line\": 111, "
+                     "  },"
+                     "  \"foo\": \"outer foo\", "
+                     "}";
+
+  JSONReader reader(jobj);
+  bool found;
+
+  found = reader.Seek("id");
+  EXPECT(found);
+  EXPECT_EQ(reader.Type(), JSONReader::kInteger);
+  found = reader.Seek("foo");
+  EXPECT(found);
+  EXPECT_EQ(reader.Type(), JSONReader::kString);
+  EXPECT(reader.IsStringLiteral("outer foo"));
+  found = reader.Seek("line");
+  EXPECT(!found);
+  found = reader.Seek("params");
+  EXPECT(found);
+  EXPECT_EQ(reader.Type(), JSONReader::kObject);
+  reader.Set(reader.ValueChars());
+  found = reader.Seek("foo");
+  EXPECT(found);
+  EXPECT_EQ(reader.Type(), JSONReader::kArray);
+  found = reader.Seek("non-existing");
+  EXPECT(!found);
+  found = reader.Seek("line");
+  EXPECT(found);
+  EXPECT_EQ(reader.Type(), JSONReader::kInteger);
+}
+
+
+TEST_CASE(JSON_TextBuffer) {
+  TextBuffer w(5);  // Small enough to make buffer grow at least once.
+  w.Printf("{ \"%s\" : %d", "length", 175);
+  EXPECT_STREQ("{ \"length\" : 175", w.buf());
+  w.Printf(", \"%s\" : \"%s\" }", "command", "stopIt");
+  EXPECT_STREQ("{ \"length\" : 175, \"command\" : \"stopIt\" }", w.buf());
+
+  JSONReader r(w.buf());
+  bool found = r.Seek("command");
+  EXPECT(found);
+  EXPECT_EQ(r.Type(), JSONReader::kString);
+  EXPECT(r.IsStringLiteral("stopIt"));
+}
+
+}  // namespace dart