Deal with exception when we don't get any versions back

CHANGELOG.md

@@ -16,6 +16,12 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+## [1.1.1] - 2019-07-24
+
+### Fixed
+
+- deal with exception when we don't get any versions back
+
 ## [1.1.0] - 2019-07-24
 
 ### Added

SIL.NuGetCleaner/NuGetPackage.cs

@@ -51,16 +51,24 @@ public async Task<List<SemanticVersion>> GetVersions()
 			var responseBody = await HttpClient.SendAsync(request);
 			var responseString = await responseBody.Content.ReadAsStringAsync();
 			_nugetPackageJson = JsonConvert.DeserializeObject(responseString);
-			CurrentVersion = SemanticVersion.Parse(_nugetPackageJson.data[0].version.ToString());
+			if (_nugetPackageJson.data.Count <= 0)
+				return null;
+
+			var versionString = _nugetPackageJson.data[0].version.ToString();
+			CurrentVersion = SemanticVersion.Parse(versionString);
 			var jsonVersions = _nugetPackageJson.data[0].versions as JArray;
 			_versions = jsonVersions.Select(versionInfo =>
 				SemanticVersion.Parse(versionInfo["version"].ToString())).ToList();
 			return _versions;
+
 		}
 
 		public async Task<List<SemanticVersion>> GetPrereleaseVersionsToDelete()
 		{
 			var versions = await GetVersions();
+			if (versions == null)
+				return null;
+
 			var prereleaseVersions = new List<SemanticVersion>();
 			foreach (var semVer in versions)
 			{

SIL.NuGetCleaner/Program.cs

@@ -22,6 +22,11 @@ private static async Task Execute(Options options)
 			var nugetPackage = new NuGetPackage(options.PackageId, options.ApiKey,
 				options.Minimum, options.Maximum);
 			var versionsToDelete = await nugetPackage.GetPrereleaseVersionsToDelete();
+			if (versionsToDelete == null)
+			{
+				Console.WriteLine($"ERROR: Can't find any versions for {options.PackageId}");
+				return;
+			}
 			if (versionsToDelete.Count == 0)
 			{
 				Console.WriteLine("No obsolete pre-release versions found.");