Merge pull request github#14834 from michaelnebel/csharp/robustassetsfileread

C#: Make assets file reading more robust.

Author: michaelnebel

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/Assets.cs

@@ -143,14 +143,31 @@ public bool TryParse(string json, DependencyContainer dependencies)
             }
         }
 
+        private static bool TryReadAllText(string path, ProgressMonitor progressMonitor, out string content)
+        {
+            try
+            {
+                content = File.ReadAllText(path);
+                return true;
+            }
+            catch (Exception e)
+            {
+                progressMonitor.LogInfo($"Failed to read assets file '{path}': {e.Message}");
+                content = "";
+                return false;
+            }
+        }
+
         public static DependencyContainer GetCompilationDependencies(ProgressMonitor progressMonitor, IEnumerable<string> assets)
         {
             var parser = new Assets(progressMonitor);
             var dependencies = new DependencyContainer();
             assets.ForEach(asset =>
             {
-                var json = File.ReadAllText(asset);
-                parser.TryParse(json, dependencies);
+                if (TryReadAllText(asset, progressMonitor, out var json))
+                {
+                    parser.TryParse(json, dependencies);
+                }
             });
             return dependencies;
         }

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/DotNet.cs

@@ -128,7 +128,7 @@ public bool Exec(string execArgs)
         [GeneratedRegex("Restored\\s+(.+\\.csproj)", RegexOptions.Compiled)]
         private static partial Regex RestoredProjectRegex();
 
-        [GeneratedRegex("[Assets\\sfile\\shas\\snot\\schanged.\\sSkipping\\sassets\\sfile\\swriting.|Writing\\sassets\\sfile\\sto\\sdisk.]\\sPath:\\s(.*)", RegexOptions.Compiled)]
+        [GeneratedRegex("[Assets\\sfile\\shas\\snot\\schanged.\\sSkipping\\sassets\\sfile\\swriting.|Writing\\sassets\\sfile\\sto\\sdisk.]\\sPath:\\s(.+)", RegexOptions.Compiled)]
         private static partial Regex AssetsFileRegex();
     }
 }