From 8989bbb1afb41404f27c76a0b083f7bb46d7fc9e Mon Sep 17 00:00:00 2001
From: NullVoxPopuli <199018+NullVoxPopuli@users.noreply.github.com>
Date: Mon, 6 Mar 2023 11:07:50 -0500
Subject: [PATCH] Add FPS utilities, resolves #658

---
 .changeset/young-walls-own.md                 | 47 ++++++++++
 ember-resources/package.json                  |  4 +
 .../function-based/immediate-invocation.ts    | 14 +--
 ember-resources/src/util/fps.ts               | 88 +++++++++++++++++++
 test-app/package.json                         |  2 +-
 test-app/tests/utils/fps/rendering-test.gts   | 63 +++++++++++++
 .../utils/function-resource/clock-test.gts    | 11 ++-
 7 files changed, 220 insertions(+), 9 deletions(-)
 create mode 100644 .changeset/young-walls-own.md
 create mode 100644 ember-resources/src/util/fps.ts
 create mode 100644 test-app/tests/utils/fps/rendering-test.gts

diff --git a/.changeset/young-walls-own.md b/.changeset/young-walls-own.md
new file mode 100644
index 000000000..efbf40b30
--- /dev/null
+++ b/.changeset/young-walls-own.md
@@ -0,0 +1,47 @@
+---
+"ember-resources": minor
+---
+
+New Utils: UpdateFrequency and FrameRate
+
+<details><summary>FrameRate</summary>
+
+ Utility that uses requestAnimationFrame to report
+ how many frames per second the current monitor is
+ rendering at.
+ 
+ The result is rounded to two decimal places.
+ 
+ ```js
+ import { FramRate } from 'ember-resources/util/fps';
+ 
+ <template>
+   {{FrameRate}}
+ </template>
+ ```
+
+</details>
+
+
+<details><summary>FrameRate</summary>
+
+
+ Utility that will report the frequency of updates to tracked data.
+ 
+ ```js
+ import { UpdateFrequency } from 'ember-resources/util/fps';
+ 
+ export default class Demo extends Component {
+   @tracked someProp;
+ 
+   @use updateFrequency = UpdateFrequency(() => this.someProp);
+ 
+   <template>
+     {{this.updateFrequency}}
+   </template>
+ }
+ ```
+ 
+ NOTE: the function passed to UpdateFrequency may not set tracked data.
+
+</details>
diff --git a/ember-resources/package.json b/ember-resources/package.json
index 550277d96..a1dca230e 100644
--- a/ember-resources/package.json
+++ b/ember-resources/package.json
@@ -15,6 +15,7 @@
     "./util": "./dist/util/index.js",
     "./util/cell": "./dist/util/cell.js",
     "./util/keep-latest": "./dist/util/keep-latest.js",
+    "./util/fps": "./dist/util/fps.js",
     "./util/map": "./dist/util/map.js",
     "./util/helper": "./dist/util/helper.js",
     "./util/remote-data": "./dist/util/remote-data.js",
@@ -43,6 +44,9 @@
       "util/function": [
         "dist/util/function.d.ts"
       ],
+      "util/fps": [
+        "dist/util/fps.d.ts"
+      ],
       "util/map": [
         "dist/util/map.d.ts"
       ],
diff --git a/ember-resources/src/core/function-based/immediate-invocation.ts b/ember-resources/src/core/function-based/immediate-invocation.ts
index b026ef4ad..04113ce18 100644
--- a/ember-resources/src/core/function-based/immediate-invocation.ts
+++ b/ember-resources/src/core/function-based/immediate-invocation.ts
@@ -134,7 +134,7 @@ class ResourceInvokerManager {
  *  })
  *  ```
  */
-export function resourceFactory<Value = unknown, Args extends unknown[] = unknown[]>(
+export function resourceFactory<Value = unknown, Args extends any[] = any[]>(
   wrapperFn: (...args: Args) => ReturnType<typeof resource<Value>>
   /**
    * This is a bonkers return type.
@@ -161,21 +161,21 @@ export function resourceFactory<Value = unknown, Args extends unknown[] = unknow
 }
 
 type ResourceBlueprint<Value, Args> =
-  /**
-   * type for JS invocation with @use
-   *   @use a = A.from(() => [b, c, d])
-   */
-  | ((thunk: () => SpreadFor<Args>) => ReturnType<typeof resource<Value>>)
   /**
    * Type for template invocation
    *  {{#let (A b c d) as |a|}}
    *     {{a}}
    *  {{/let}}
+   *
+   * This could also be used in JS w/ invocation with @use
+   *   @use a = A(() => b)
+   *
+   * NOTE: it is up to the function passed to resourceFactory to handle some of the parameter ambiguity
    */
   | ((...args: SpreadFor<Args>) => ReturnType<typeof resource<Value>>)
   /**
    * Not passing args is allowed, too
-   *   @use a = A.from()
+   *   @use a = A()
    *
    *   {{A}}
    */
diff --git a/ember-resources/src/util/fps.ts b/ember-resources/src/util/fps.ts
new file mode 100644
index 000000000..be63688fd
--- /dev/null
+++ b/ember-resources/src/util/fps.ts
@@ -0,0 +1,88 @@
+import { cell, resource, resourceFactory } from '../index';
+
+/**
+ * Utility that uses requestAnimationFrame to report
+ * how many frames per second the current monitor is
+ * rendering at.
+ *
+ * The result is rounded to two decimal places.
+ *
+ * ```js
+ * import { FramRate } from 'ember-resources/util/fps';
+ *
+ * <template>
+ *   {{FrameRate}}
+ * </template>
+ * ```
+ */
+export const FrameRate = resource(({ on }) => {
+  let value = cell(0);
+  let startTime = new Date().getTime();
+  let frame: number;
+
+  let update = () => {
+    // simulate receiving data as fast as possible
+    frame = requestAnimationFrame(() => {
+      value.current++;
+      update();
+    });
+  };
+
+  on.cleanup(() => cancelAnimationFrame(frame));
+
+  // Start the infinite requestAnimationFrame chain
+  update();
+
+  return () => {
+    let elapsed = (new Date().getTime() - startTime) * 0.001;
+    let fps = value.current * Math.pow(elapsed, -1);
+    let rounded = Math.round(fps * 100) * 0.01;
+    // account for https://stackoverflow.com/a/588014/356849
+    let formatted = `${rounded}`.substring(0, 5);
+
+    return formatted;
+  };
+});
+
+/**
+ * Utility that will report the frequency of updates to tracked data.
+ *
+ * ```js
+ * import { UpdateFrequency } from 'ember-resources/util/fps';
+ *
+ * export default class Demo extends Component {
+ *   @tracked someProp;
+ *
+ *   @use updateFrequency = UpdateFrequency(() => this.someProp);
+ *
+ *   <template>
+ *     {{this.updateFrequency}}
+ *   </template>
+ * }
+ * ```
+ *
+ * NOTE: the function passed to UpdateFrequency may not set tracked data.
+ */
+export const UpdateFrequency = resourceFactory((ofWhat: () => unknown, updateInterval = 500) => {
+  updateInterval ||= 500;
+
+  let multiplier = 1000 / updateInterval;
+  let framesSinceUpdate = 0;
+
+  return resource(({ on }) => {
+    let value = cell(0);
+    let interval = setInterval(() => {
+      value.current = framesSinceUpdate * multiplier;
+      framesSinceUpdate = 0;
+    }, updateInterval);
+
+    on.cleanup(() => clearInterval(interval));
+
+    return () => {
+      ofWhat();
+      framesSinceUpdate++;
+
+      return value.current;
+    };
+  });
+});
diff --git a/test-app/package.json b/test-app/package.json
index d364a1ad2..58faa605e 100644
--- a/test-app/package.json
+++ b/test-app/package.json
@@ -137,7 +137,7 @@
   },
   "packageManager": "pnpm@7.1.2",
   "volta": {
-    "extends": "../../package.json"
+    "extends": "../package.json"
   },
   "msw": {
     "workerDirectory": "public"
diff --git a/test-app/tests/utils/fps/rendering-test.gts b/test-app/tests/utils/fps/rendering-test.gts
new file mode 100644
index 000000000..9fea87ce9
--- /dev/null
+++ b/test-app/tests/utils/fps/rendering-test.gts
@@ -0,0 +1,63 @@
+import Component from '@glimmer/component';
+import { tracked } from '@glimmer/tracking';
+// @ts-ignore
+import { on } from '@ember/modifier';
+import { click, find, render } from '@ember/test-helpers';
+import { module, test } from 'qunit';
+import { setupRenderingTest } from 'ember-qunit';
+
+import { use } from 'ember-resources';
+import { FrameRate, UpdateFrequency } from 'ember-resources/util/fps';
+
+module('Utils | FPS | rendering', function (hooks) {
+  setupRenderingTest(hooks);
+
+  module('FrameRate', function() {
+    test('it works', async function (assert) {
+      await render(<template>
+        <out>{{FrameRate}}</out>
+      </template>);
+
+
+      let text = find('out')?.innerHTML?.trim() || ''
+
+      assert.notStrictEqual(text, '', 'Content is rendered');
+    });
+
+
+  });
+
+  module('UpdateFrequency', function() {
+    test('it works', async function (assert) {
+      class Demo extends Component {
+        @tracked someProp = 0;
+
+        @use updateFrequency = UpdateFrequency(() => this.someProp);
+
+        inc = () => this.someProp++;
+
+        <template>
+          <button type="button" {{on "click" this.inc}}>Inc</button>
+          <out>{{this.updateFrequency}}</out>
+        </template>
+      }
+
+      await render(
+        <template>
+          <Demo />
+        </template>
+      );
+
+      assert.dom('out').hasText('0', 'Initial value is 0');
+
+      for (let i = 0; i < 100; i++) {
+        await click('button');
+      }
+
+      let text = find('out')?.innerHTML?.trim() || ''
+
+      assert.notStrictEqual(text, '', 'Content is rendered');
+    });
+  });
+
+});
diff --git a/test-app/tests/utils/function-resource/clock-test.gts b/test-app/tests/utils/function-resource/clock-test.gts
index c077855f0..e9041143b 100644
--- a/test-app/tests/utils/function-resource/clock-test.gts
+++ b/test-app/tests/utils/function-resource/clock-test.gts
@@ -15,8 +15,17 @@ module('Examples | resource | Clock', function (hooks) {
     assert.timeout(3000);
   });
 
+  interface ClockArgs {
+    start?: Date;
+    locale?: string;
+  }
+
   // Wrapper functions are the only way to pass Args to a resource.
-  const Clock = resourceFactory(({ start, locale = 'en-US' }: { start?: Date, locale?: string }) => {
+  const Clock = resourceFactory((options: ClockArgs | (() => ClockArgs)) => {
+    let opts = (typeof options === 'function') ? options() : options;
+    let start = opts.start;
+    let locale = opts.locale ?? 'en-US';
+
     // For a persistent state across arg changes, `Resource` may be better`
     let time = cell(start);
     let formatter = new Intl.DateTimeFormat(locale, {