/// <summary>
/// Provides a preset CommandEvaluator instance for evaluating strings containing the source placeholder.
/// </summary>
/// <param name="source">The source placeholder value</param>
/// <returns>A CommandEvaluator instance for evaluating strings containing the source placeholder.</returns>
private static CommandEvaluator BuildEvaluator(string source)
{
CommandEvaluator evaluator = new CommandEvaluator();
evaluator.SetVariable(SourcePlaceholder, source);
return evaluator;
}
/// <summary>
/// Executes the discovery command as specified in the configuration for the requested test source.
/// </summary>
/// <param name="source">The test source module</param>
/// <returns>The test framework describing all tests contained within the test source or null if one cannot be provided.</returns>
private TestFramework ExecuteExternalDiscoveryCommand(string source)
{
// Use a temporary file to host the result of the external discovery process
string path = Path.Combine(Path.GetDirectoryName(source), Path.GetFileName(source) + ListFileSuffix);
// Perform cleanup to avoid inconsistent listing
if (File.Exists(path))
{
File.Delete(path);
}
CommandEvaluator evaluator = new CommandEvaluator();
evaluator.SetVariable("source", source);
evaluator.SetVariable("out", path);
// Evaluate the discovery command
CommandLine commandLine = new CommandLine
{
FileName = evaluator.Evaluate(this.Settings.DiscoveryCommandLine.FileName).Result,
Arguments = evaluator.Evaluate(this.Settings.DiscoveryCommandLine.Arguments).Result
};
// Execute the discovery command via an external process
if (ExecuteCommand(commandLine))
{
// Parse the generate TestFramework from the temporary file
return ParseTestFramework(path);
}
return null;
}