Allow Restore to discard pending changes (#6330)

* allow restoring of a tag when changes have already been made
* add test that checks whether restoring different tag for same assets will discard pending changes

Co-authored-by: Ben Broderick Phillips <[email protected]>

tools/test-proxy/Azure.Sdk.Tools.TestProxy.Tests/IntegrationTests/GitStoreIntegrationRestoreTests.cs

@@ -335,6 +335,78 @@ public async Task InvalidTagThrows(string inputJson, string httpException)
             }
         }
 
+        [EnvironmentConditionalSkipTheory]
+        [InlineData(
+        @"{
+              ""AssetsRepo"": ""Azure/azure-sdk-assets-integration"",
+              ""AssetsRepoPrefixPath"": ""pull/scenarios"",
+              ""AssetsRepoId"": """",
+              ""TagPrefix"": ""main"",
+              ""Tag"": ""python/tables_9e81fb""
+        }")]
+        [Trait("Category", "Integration")]
+        public async Task VerifyRestoreDiscardsChanges(string inputJson)
+        {
+            var folderStructure = new string[]
+            {
+                GitStoretests.AssetsJson
+            };
+
+            Assets assets = JsonSerializer.Deserialize<Assets>(inputJson);
+            var testFolder = TestHelpers.DescribeTestFolder(assets, folderStructure);
+            try
+            {
+                var jsonFileLocation = Path.Join(testFolder, GitStoretests.AssetsJson);
+
+                var parsedConfiguration = await _defaultStore.ParseConfigurationFile(jsonFileLocation);
+                await _defaultStore.Restore(jsonFileLocation);
+
+                // Calling Path.GetFullPath of the Path.Combine will ensure any directory separators are normalized for
+                // the OS the test is running on. The reason being is that AssetsRepoPrefixPath, if there's a separator,
+                // will be a forward one as expected by git but on Windows this won't result in a usable path.
+                string localFilePath = Path.GetFullPath(Path.Combine(parsedConfiguration.AssetsRepoLocation.ToString(), parsedConfiguration.AssetsRepoPrefixPath.ToString()));
+
+                // Verify files from Tag
+                Assert.Equal(4, System.IO.Directory.EnumerateFiles(localFilePath).Count());
+                Assert.True(TestHelpers.VerifyFileVersion(localFilePath, "file1.txt", 1));
+                Assert.True(TestHelpers.VerifyFileVersion(localFilePath, "file2.txt", 2));
+                Assert.True(TestHelpers.VerifyFileVersion(localFilePath, "file3.txt", 2));
+                Assert.True(TestHelpers.VerifyFileVersion(localFilePath, "file4.txt", 1));
+
+                // Delete a couple of files
+                File.Delete(Path.Combine(localFilePath, "file2.txt"));
+                File.Delete(Path.Combine(localFilePath, "file4.txt"));
+
+                // Add a file
+                TestHelpers.CreateFileWithInitialVersion(localFilePath, "file5.txt");
+
+                // Verify the set of files after the additions/deletions
+                Assert.Equal(3, System.IO.Directory.EnumerateFiles(localFilePath).Count());
+                Assert.True(TestHelpers.VerifyFileVersion(localFilePath, "file1.txt", 1));
+                Assert.True(TestHelpers.VerifyFileVersion(localFilePath, "file3.txt", 2));
+                Assert.True(TestHelpers.VerifyFileVersion(localFilePath, "file5.txt", 1));
+
+                // simulate a feature branch checkout in the langauge repo. change the targeted
+                // tag in place. The changes from lines above should be automatically discarded.
+                var existingAssets = TestHelpers.LoadAssetsFromFile(jsonFileLocation);
+                existingAssets.Tag = "python/tables_fc54d0";
+                TestHelpers.UpdateAssetsFile(existingAssets, jsonFileLocation);
+
+                await _defaultStore.Restore(jsonFileLocation);
+
+                // Verify the only files there are ones from the Tag
+                Assert.Equal(3, System.IO.Directory.EnumerateFiles(localFilePath).Count());
+                Assert.True(TestHelpers.VerifyFileVersion(localFilePath, "file1.txt", 1));
+                Assert.True(TestHelpers.VerifyFileVersion(localFilePath, "file2.txt", 1));
+                Assert.True(TestHelpers.VerifyFileVersion(localFilePath, "file3.txt", 1));
+                await TestHelpers.CheckBreadcrumbAgainstAssetsJsons(new string[] { jsonFileLocation });
+            }
+            finally
+            {
+                DirectoryHelper.DeleteGitDirectory(testFolder);
+            }
+        }
+
         [EnvironmentConditionalSkipTheory]
         [InlineData(
         @"{

tools/test-proxy/Azure.Sdk.Tools.TestProxy/Store/GitStore.cs

@@ -162,7 +162,7 @@ public async Task<string> Restore(string pathToAssetsJson) {
                 InitializeAssetsRepo(config);
             }
 
-            CheckoutRepoAtConfig(config);
+            CheckoutRepoAtConfig(config, cleanEnabled: true);
             await BreadCrumb.Update(config);
 
             return config.AssetsRepoLocation.ToString();
@@ -214,27 +214,31 @@ public async Task Reset(string pathToAssetsJson)
 
             if (allowReset)
             {
-                try
-                {
-                    GitHandler.Run("checkout *", config);
-                    GitHandler.Run("clean -xdf", config);
-                }
-                catch(GitProcessException e)
-                {
-                    HideOrigin(config);
-                    throw GenerateInvokeException(e.Result);
-                }
-
                 if (!string.IsNullOrWhiteSpace(config.Tag))
                 {
-                    CheckoutRepoAtConfig(config);
+                    Clean(config);
+                    CheckoutRepoAtConfig(config, cleanEnabled: false);
                     await BreadCrumb.Update(config);
                 }
             }
 
             HideOrigin(config);
         }
 
+        private void Clean(GitAssetsConfiguration config)
+        {
+            try
+            {
+                GitHandler.Run("checkout *", config);
+                GitHandler.Run("clean -xdf", config);
+            }
+            catch (GitProcessException e)
+            {
+                HideOrigin(config);
+                throw GenerateInvokeException(e.Result);
+            }
+        }
+
         /// <summary>
         /// Given a CommandResult, generate an HttpException.
         /// </summary>
@@ -297,12 +301,20 @@ private void HideOrigin(GitAssetsConfiguration config)
         /// Given a configuration, set the sparse-checkout directory for the config, then attempt checkout of the targeted Tag.
         /// </summary>
         /// <param name="config"></param>
-        public void CheckoutRepoAtConfig(GitAssetsConfiguration config)
+        /// <param name="cleanEnabled">A newly initialized repo should not be 'cleaned', as that will result in a git error. However, a new
+        /// clone looks the same as being on the wrong tag. This variable allows us to prevent over-active cleaning that would result in exceptions.</param>
+        public void CheckoutRepoAtConfig(GitAssetsConfiguration config, bool cleanEnabled = true)
         {
+            // we are already on a targeted tag and as such don't want to discard our recordings
             if (Assets.TryGetValue(config.AssetsJsonRelativeLocation.ToString(), out var value) && value == config.Tag)
             {
                 return;
             }
+            // if we are NOT on our targeted tag, before we attempt to switch we need to reset without asking for permission
+            else if (cleanEnabled)
+            {
+                Clean(config);
+            }
 
             var checkoutPaths = ResolveCheckoutPaths(config);
 
@@ -466,7 +478,7 @@ public bool InitializeAssetsRepo(GitAssetsConfiguration config, bool forceInit =
                     throw GenerateInvokeException(e.Result);
                 }
 
-                CheckoutRepoAtConfig(config);
+                CheckoutRepoAtConfig(config, cleanEnabled: false);
                 workCompleted = true;
             }