feat: Add proxying support for images (#2427)

- Closes #2418

tests/components-lib/cached-value-controller.test.ts

@@ -9,25 +9,50 @@ describe('CachedValueController', () => {
     vi.useRealTimers();
   });
 
+  it('should not restart timer on hostUpdate if not connected', () => {
+    const host = mock<ReactiveControllerHost & HTMLElement>();
+    const callback = vi.fn().mockReturnValue(42);
+    let refreshSeconds: number | null = 10;
+
+    const controller = new CachedValueController(host, () => refreshSeconds, callback);
+
+    Object.defineProperty(host, 'isConnected', { get: () => false });
+
+    refreshSeconds = 20;
+    controller.hostUpdate();
+    expect(controller.hasTimer()).toBeFalsy();
+  });
+
+  it('should not restart timer if unchanged on hostUpdate', () => {
+    const host = mock<ReactiveControllerHost & HTMLElement>();
+    const callback = vi.fn().mockReturnValue(42);
+    const refreshSeconds: number | null = 10;
+
+    const controller = new CachedValueController(host, () => refreshSeconds, callback);
+
+    Object.defineProperty(host, 'isConnected', { get: () => true });
+
+    // This starts the timer as isConnected is true
+    controller.hostConnected();
+
+    const startTimerSpy = vi.spyOn(controller, 'startTimer');
+
+    controller.hostUpdate();
+
+    // Should not restart since refreshSeconds hasn't changed
+    expect(startTimerSpy).not.toBeCalled();
+  });
+
   it('should construct', () => {
-    const host = mock<ReactiveControllerHost>();
+    const host = mock<ReactiveControllerHost & HTMLElement>();
     const callback = vi.fn();
-    const controller = new CachedValueController(host, 10, callback);
+    const controller = new CachedValueController(host, () => 10, callback);
 
     expect(controller).toBeTruthy();
   });
 
-  it('should remove host', () => {
-    const host = mock<ReactiveControllerHost>();
-    const callback = vi.fn();
-    const controller = new CachedValueController(host, 10, callback);
-
-    controller.removeController();
-    expect(host.removeController).toBeCalled();
-  });
-
   it('should have timer', () => {
-    const host = mock<ReactiveControllerHost>();
+    const host = mock<ReactiveControllerHost & HTMLElement>();
     const callback = vi.fn();
     const startCallback = vi.fn();
     const stopCallback = vi.fn();
@@ -36,7 +61,7 @@ describe('CachedValueController', () => {
 
     const controller = new CachedValueController(
       host,
-      10,
+      () => 10,
       callback,
       startCallback,
       stopCallback,
@@ -49,13 +74,13 @@ describe('CachedValueController', () => {
     vi.runOnlyPendingTimers();
     expect(callback).toBeCalled();
     expect(host.requestUpdate).toBeCalled();
-    expect(controller.value).toBe(3);
+    expect(controller.getValue()).toBe(3);
 
     callback.mockReturnValue(4);
     vi.runOnlyPendingTimers();
     expect(callback).toBeCalled();
     expect(host.requestUpdate).toBeCalled();
-    expect(controller.value).toBe(4);
+    expect(controller.getValue()).toBe(4);
 
     expect(controller.hasTimer()).toBeTruthy();
 
@@ -68,42 +93,129 @@ describe('CachedValueController', () => {
   });
 
   it('should clear value', () => {
-    const host = mock<ReactiveControllerHost>();
+    const host = mock<ReactiveControllerHost & HTMLElement>();
     const callback = vi.fn().mockReturnValue(42);
 
     vi.useFakeTimers();
 
-    const controller = new CachedValueController(host, 10, callback);
+    const controller = new CachedValueController(host, () => 10, callback);
     controller.startTimer();
 
     vi.runOnlyPendingTimers();
-    expect(controller.value).equal(42);
+    expect(controller.getValue()).equal(42);
 
     controller.clearValue();
-    expect(controller.value).toBeUndefined();
+    expect(controller.getValue()).toBeNull();
   });
 
   it('should connect and disconnect host', () => {
-    const host = mock<ReactiveControllerHost>();
+    const host = mock<ReactiveControllerHost & HTMLElement>();
     const callback = vi.fn().mockReturnValue(43);
     const startCallback = vi.fn();
     const stopCallback = vi.fn();
 
     const controller = new CachedValueController(
       host,
-      10,
+      () => 10,
       callback,
       startCallback,
       stopCallback,
     );
 
     controller.hostConnected();
-    expect(controller.value).equal(43);
+    expect(controller.getValue()).equal(43);
     expect(startCallback).toBeCalled();
     expect(host.requestUpdate).toBeCalled();
 
     controller.hostDisconnected();
-    expect(controller.value).toBeUndefined();
+    expect(controller.getValue()).toBeNull();
     expect(stopCallback).toBeCalled();
   });
+
+  it('should call timer tick callback on each tick before updateValue', () => {
+    const host = mock<ReactiveControllerHost & HTMLElement>();
+    const callback = vi.fn().mockReturnValue('value');
+    const tickCallback = vi.fn();
+
+    vi.useFakeTimers();
+
+    const controller = new CachedValueController(
+      host,
+      () => 5,
+      callback,
+      undefined,
+      undefined,
+      tickCallback,
+    );
+
+    controller.startTimer();
+
+    vi.runOnlyPendingTimers();
+    expect(tickCallback).toHaveBeenCalledTimes(1);
+    expect(callback).toHaveBeenCalledTimes(1);
+
+    vi.runOnlyPendingTimers();
+    expect(tickCallback).toHaveBeenCalledTimes(2);
+    expect(callback).toHaveBeenCalledTimes(2);
+  });
+
+  it('should not call timerTickCallback on manual updateValue', () => {
+    const host = mock<ReactiveControllerHost & HTMLElement>();
+    const callback = vi.fn().mockReturnValue('value');
+    const tickCallback = vi.fn();
+
+    const controller = new CachedValueController(
+      host,
+      () => 5,
+      callback,
+      undefined,
+      undefined,
+      tickCallback,
+    );
+
+    controller.updateValue();
+    expect(callback).toHaveBeenCalledTimes(1);
+    expect(tickCallback).not.toHaveBeenCalled();
+  });
+
+  it('should restart timer with new interval on hostUpdate', () => {
+    const host = mock<ReactiveControllerHost & HTMLElement>();
+    const callback = vi.fn().mockReturnValue(42);
+    let refreshSeconds: number | null = null;
+
+    const controller = new CachedValueController(host, () => refreshSeconds, callback);
+
+    vi.useFakeTimers();
+    Object.defineProperty(host, 'isConnected', { get: () => true });
+    controller.hostConnected();
+    expect(controller.hasTimer()).toBeFalsy();
+
+    refreshSeconds = 20;
+    controller.hostUpdate();
+
+    // Timer should have been restarted. Fast forward 15 seconds. If it didn't
+    // restart, it would fire at 10 seconds. Since it restarted at 20 seconds,
+    // it shouldn't fire at 15 seconds.
+    callback.mockClear();
+    vi.advanceTimersByTime(15 * 1000);
+    expect(callback).not.toBeCalled();
+
+    vi.advanceTimersByTime(5 * 1000);
+    expect(callback).toBeCalled();
+
+    // Now set it to null -> stops timer
+    refreshSeconds = null;
+    controller.hostUpdate();
+    expect(controller.hasTimer()).toBeFalsy();
+
+    // Now set it to 0 -> stops timer
+    refreshSeconds = 0;
+    controller.hostUpdate();
+    expect(controller.hasTimer()).toBeFalsy();
+
+    // Now set it to negative -> stops timer
+    refreshSeconds = -1;
+    controller.hostUpdate();
+    expect(controller.hasTimer()).toBeFalsy();
+  });
 });