File Append Method (#881)

Author: thomhurst

src/ModularPipelines.Build/ReleaseNotes.md

@@ -0,0 +1 @@
+* Add File.AppendAsync method

src/ModularPipelines.GitHub/GitHubMarkdownSummaryGenerator.cs

@@ -33,7 +33,7 @@ public async Task OnEndAsync(IPipelineHookContext pipelineContext, PipelineSumma
             return;
         }
 
-        await pipelineContext.FileSystem.GetFile(stepSummaryVariable).WriteAsync($"{mermaid}\n\n{table}\n\n{_afterPipelineLogger.GetOutput()}{exception}");
+        await pipelineContext.FileSystem.GetFile(stepSummaryVariable).AppendAsync($"{mermaid}\n\n{table}\n\n{_afterPipelineLogger.GetOutput()}{exception}");
     }
 
     private async Task<string> GetException(PipelineSummary pipelineSummary)

src/ModularPipelines/FileSystem/File.cs

@@ -98,6 +98,20 @@ public async Task WriteAsync(Stream contents, CancellationToken cancellationToke
 
         await contents.CopyToAsync(fileStream, cancellationToken);
     }
+    
+    public Task AppendAsync(string contents, CancellationToken cancellationToken = default)
+    {
+        ModuleLogger.Current.LogInformation("Writing to File: {Path}", this);
+        
+        return System.IO.File.AppendAllTextAsync(Path, contents, cancellationToken);
+    }
+
+    public Task AppendAsync(IEnumerable<string> contents, CancellationToken cancellationToken = default)
+    {
+        ModuleLogger.Current.LogInformation("Writing to File: {Path}", this);
+        
+        return System.IO.File.AppendAllLinesAsync(Path, contents, cancellationToken);
+    }
 
     /// <inheritdoc cref="FileSystemInfo.Exists"/>>
     public bool Exists => FileInfo.Exists;