Source
void replaceAqueductDependencyString(
String destDirectoryPath, String aqueductVersion) {
var pubspecFile =
new File(path_lib.join(destDirectoryPath, "pubspec.yaml"));
var contents = pubspecFile.readAsStringSync();
contents = contents.replaceFirst("aqueduct: ^2.0.0", aqueductVersion);
pubspecFile.writeAsStringSync(contents);
}