VSCode: Schema tag switching

package.json

@@ -76,6 +76,7 @@
     "prettier": "1.14.2",
     "ts-jest": "^23.1.4",
     "ts-node": "^7.0.1",
+    "tsc-watch": "^1.0.30",
     "tslib": "^1.9.3",
     "typescript": "^3.0.3",
     "vsce": "^1.46.0"

packages/apollo-language-server/package.json

@@ -17,9 +17,9 @@
     "installServer": "installServerIntoExtension ../apollo-vscode ./package.json ./tsconfig.json && ./copy-apollo-libs.sh",
     "clean": "rm -rf ../apollo-vscode/server",
     "prebuild": "npm run clean",
-    "build": "npm run installServer && tsc -p .",
-    "watch": "npm run installServer && tsc -w -p .",
-    "watchOnly": "tsc -w -p .",
+    "build": "npm run installServer && tsc",
+    "watch": "npm run installServer && tsc-watch --onSuccess \"./copy-apollo-libs.sh\"",
+    "watchOnly": "tsc -w",
     "prepare": "npm run build"
   },
   "engines": {

packages/apollo-language-server/src/loadingHandler.ts

@@ -0,0 +1,55 @@
+import { IConnection, NotificationType } from "vscode-languageserver";
+
+export class LoadingHandler {
+  constructor(private connection: IConnection) {}
+  private latestLoadingToken = 0;
+  async handle<T>(message: string, value: Promise<T>): Promise<T> {
+    const token = this.latestLoadingToken;
+    this.latestLoadingToken += 1;
+    this.connection.sendNotification(
+      new NotificationType<any, void>("apollographql/loading"),
+      { message, token }
+    );
+    try {
+      const ret = await value;
+      this.connection.sendNotification(
+        new NotificationType<any, void>("apollographql/loadingComplete"),
+        token
+      );
+      return ret;
+    } catch (e) {
+      this.connection.sendNotification(
+        new NotificationType<any, void>("apollographql/loadingComplete"),
+        token
+      );
+      this.showError(`Error in "${message}": ${e}`);
+      throw e;
+    }
+  }
+  handleSync<T>(message: string, value: () => T): T {
+    const token = this.latestLoadingToken;
+    this.latestLoadingToken += 1;
+    this.connection.sendNotification(
+      new NotificationType<any, void>("apollographql/loading"),
+      { message, token }
+    );
+    try {
+      const ret = value();
+      this.connection.sendNotification(
+        new NotificationType<any, void>("apollographql/loadingComplete"),
+        token
+      );
+      return ret;
+    } catch (e) {
+      this.connection.sendNotification(
+        new NotificationType<any, void>("apollographql/loadingComplete"),
+        token
+      );
+      this.showError(`Error in "${message}": ${e}`);
+      throw e;
+    }
+  }
+  showError(message: string) {
+    this.connection.window.showErrorMessage(message);
+  }
+}