(core) Adding UI for timing API

Summary:
Adding new buttons to control the `timing` API and a way to view the results
using virtual table features.

Test Plan: Added new

Reviewers: georgegevoian

Reviewed By: georgegevoian

Subscribers: paulfitz

Differential Revision: https://phab.getgrist.com/D4252

test/server/lib/helpers/Signal.ts

@@ -1,44 +1,58 @@
-import {delay} from "bluebird";
+import {delay} from 'bluebird';
+import {assert} from 'chai';
 
 /**
  * Helper that creates a promise that can be resolved from outside.
+ *
+ * @example
+ * const methodCalled = signal();
+ * setTimeout(() => methodCalled.emit(), 1000);
+ * methodCalled.assertNotCalled(); // won't throw as the method hasn't been called yet
+ * await methodCalled.wait(); // will wait for the method to be called
+ * await methodCalled.wait(); // can be called multiple times
+ * methodCalled.reset(); // resets the signal (so that it can be awaited again)
+ * setTimeout(() => methodCalled.emit(), 3000);
+ * await methodCalled.wait(); // will fail, as we wait only 2 seconds
  */
 export function signal() {
-    let resolve: null | ((data: any) => void) = null;
-    let promise: null | Promise<any> = null;
-    let called = false;
-    return {
-        emit(data: any) {
-            if (!resolve) {
-                throw new Error("signal.emit() called before signal.reset()");
-            }
-            called = true;
-            resolve(data);
-        },
-        async wait() {
-            if (!promise) {
-                throw new Error("signal.wait() called before signal.reset()");
-            }
-            const proms = Promise.race([promise, delay(2000).then(() => {
-                throw new Error("signal.wait() timed out");
-            })]);
-            return await proms;
-        },
-        async waitAndReset() {
-            try {
-                return await this.wait();
-            } finally {
-                this.reset();
-            }
-        },
-        called() {
-            return called;
-        },
-        reset() {
-            called = false;
-            promise = new Promise((res) => {
-                resolve = res;
-            });
-        }
-    };
+  let resolve: null | ((data: any) => void) = null;
+  let promise: null | Promise<any> = null;
+  let called = false;
+  return {
+    emit(data: any) {
+      if (!resolve) {
+        throw new Error("signal.emit() called before signal.reset()");
+      }
+      called = true;
+      resolve(data);
+    },
+    async wait() {
+      if (!promise) {
+        throw new Error("signal.wait() called before signal.reset()");
+      }
+      const proms = Promise.race([
+        promise,
+        delay(2000).then(() => {
+          throw new Error("signal.wait() timed out");
+        }),
+      ]);
+      return await proms;
+    },
+    async waitAndReset() {
+      try {
+        return await this.wait();
+      } finally {
+        this.reset();
+      }
+    },
+    assertNotCalled() {
+      assert.isFalse(called);
+    },
+    reset() {
+      called = false;
+      promise = new Promise((res) => {
+        resolve = res;
+      });
+    },
+  };
 }