added hotreload

Packages/com.singularitygroup.hotreload/Editor/CompileChecker/DefaultCompileChecker.cs

@@ -0,0 +1,70 @@
+#if UNITY_2019_1_OR_NEWER
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using UnityEditor;
+using UnityEditor.Compilation;
+using UnityEngine;
+
+namespace SingularityGroup.HotReload.Editor {
+    class DefaultCompileChecker : ICompileChecker {
+        const string recompileFilePath = PackageConst.LibraryCachePath + "/recompile.txt";
+        public bool hasCompileErrors { get; private set;  }
+        bool recompile;
+        public DefaultCompileChecker() {
+            CompilationPipeline.assemblyCompilationFinished += DetectCompileErrors;
+            CompilationPipeline.compilationFinished += OnCompilationFinished;
+            var currentSessionId = EditorAnalyticsSessionInfo.id;
+            Task.Run(() => {
+                try {
+                    var compileSessionId = File.ReadAllText(recompileFilePath);
+                    if(compileSessionId == currentSessionId.ToString()) {
+                        ThreadUtility.RunOnMainThread(() => {
+                            recompile = true;
+                            _onCompilationFinished?.Invoke();
+                        });
+                    }
+                    File.Delete(recompileFilePath);
+                } catch(DirectoryNotFoundException) {
+                   //dir doesn't exist -> no recompile required
+                } catch(FileNotFoundException) {
+                   //file doesn't exist -> no recompile required
+                } catch(Exception ex) {
+                    Log.Warning("compile checker encountered issue: {0} {1}", ex.GetType().Name, ex.Message);
+                }
+            });
+        }
+        
+        void DetectCompileErrors(string _, CompilerMessage[] messages) {
+            for (int i = 0; i < messages.Length; i++) {
+                if (messages[i].type == CompilerMessageType.Error) {
+                    hasCompileErrors = true;
+                    return;
+                }
+            }
+            hasCompileErrors = false;
+        }
+
+        void OnCompilationFinished(object _) {
+            //Don't recompile on compile errors
+            if(!hasCompileErrors) {
+                Directory.CreateDirectory(Path.GetDirectoryName(recompileFilePath));
+                File.WriteAllText(recompileFilePath, EditorAnalyticsSessionInfo.id.ToString());
+            }
+        }
+
+        Action _onCompilationFinished;
+        public event Action onCompilationFinished {
+            add {
+                if(recompile && value != null) {
+                    value();
+                }
+                _onCompilationFinished += value;
+            }
+            remove {
+                _onCompilationFinished -= value;
+            }
+        }
+    }
+}
+#endif