Ensure push of an unrestored assets.json is a recognizable error (#…

…4868)

* and set environment exit code to -1

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

@@ -85,6 +85,18 @@ public async Task<string> GetPath(string pathToAssetsJson)
         /// <returns></returns>
         public async Task Push(string pathToAssetsJson) {
             var config = await ParseConfigurationFile(pathToAssetsJson);
+
+            var initialized = IsAssetsRepoInitialized(config);
+
+            if (!initialized)
+            {
+                _consoleWrapper.WriteLine($"The targeted assets.json \"{config.AssetsJsonRelativeLocation}\" has not been restored prior to attempting push. " +
+                    $"Are you certain you're pushing the correct assets.json? Please invoke \'test-proxy restore \"{config.AssetsJsonRelativeLocation}\"\' prior to invoking a push operation.");
+
+                Environment.ExitCode = -1;
+                return;
+            }
+
             var pendingChanges = DetectPendingChanges(config);
             var generatedTagName = config.TagPrefix;