Throws an error describing an invalid response from the server.

void invalidServerResponse(http.Response response) {
 throw 'Invalid server response:\n${response.body}';
}

Parses a response body, assuming it's JSON-formatted. Throws a user-friendly error if the response body is invalid JSON, or if it's not a map.

Map parseJsonResponse(http.Response response) {
 var value;
 try {
   value = json.parse(response.body);
 } catch (e) {
   // TODO(nweiz): narrow this catch clause once issue 6775 is fixed.
   invalidServerResponse(response);
 }
 if (value is! Map) invalidServerResponse(response);
 return value;
}

Handles an unsuccessful JSON-formatted response from pub.dartlang.org.

These responses are expected to be of the form {"error": {"message": "some message"}}. If the format is correct, the message will be raised as an error; otherwise an invalidServerResponse error will be raised.

void handleJsonError(http.Response response) {
 var errorMap = parseJsonResponse(response);
 if (errorMap['error'] is! Map ||
     !errorMap['error'].containsKey('message') ||
     errorMap['error']['message'] is! String) {
   invalidServerResponse(response);
 }
 throw errorMap['error']['message'];
}

The HTTP client to use for all HTTP requests. Handles a successful JSON-formatted response from pub.dartlang.org.

These responses are expected to be of the form {"success": {"message": "some message"}}. If the format is correct, the message will be printed; otherwise an error will be raised.

void handleJsonSuccess(http.Response response) {
 var parsed = parseJsonResponse(response);
 if (parsed['success'] is! Map ||
     !parsed['success'].containsKey('message') ||
     parsed['success']['message'] is! String) {
   invalidServerResponse(response);
 }
 log.message(parsed['success']['message']);
}