fix(studio): switch keyframe ease modes optimistically

Author: miguel-heygen

packages/core/package-subpaths.json

@@ -110,6 +110,12 @@
       "types": "./dist/runtime/clipTree.d.ts",
       "environments": ["browser", "bun", "node"]
     },
+    "./runtime/custom-ease": {
+      "source": "./src/runtime/customEase.ts",
+      "runtime": "./dist/runtime/customEase.js",
+      "types": "./dist/runtime/customEase.d.ts",
+      "environments": ["browser", "bun", "node"]
+    },
     "./runtime/start-expression": {
       "source": "./src/runtime/startExpression.ts",
       "runtime": "./dist/runtime/startExpression.js",

packages/core/package.json

@@ -119,6 +119,12 @@
       "import": "./src/runtime/clipTree.ts",
       "types": "./src/runtime/clipTree.ts"
     },
+    "./runtime/custom-ease": {
+      "bun": "./src/runtime/customEase.ts",
+      "node": "./dist/runtime/customEase.js",
+      "import": "./src/runtime/customEase.ts",
+      "types": "./src/runtime/customEase.ts"
+    },
     "./runtime/start-expression": {
       "bun": "./src/runtime/startExpression.ts",
       "node": "./dist/runtime/startExpression.js",
@@ -353,6 +359,10 @@
         "import": "./dist/runtime/clipTree.js",
         "types": "./dist/runtime/clipTree.d.ts"
       },
+      "./runtime/custom-ease": {
+        "import": "./dist/runtime/customEase.js",
+        "types": "./dist/runtime/customEase.d.ts"
+      },
       "./runtime/start-expression": {
         "import": "./dist/runtime/startExpression.js",
         "types": "./dist/runtime/startExpression.d.ts"

packages/core/tsconfig.json

@@ -15,6 +15,7 @@
   },
   "files": [
     "src/runtime/clipTree.ts",
+    "src/runtime/customEase.ts",
     "src/runtime/mediaVolumeEnvelope.ts",
     "src/runtime/positionEdits.ts",
     "src/runtime/protocol.ts",

packages/studio/src/components/editor/AnimationCard.test.tsx

@@ -85,10 +85,15 @@ function findButton(host: HTMLElement, text: string): HTMLButtonElement | undefi
   );
 }
 
+function openSegment(host: HTMLElement, label: string): void {
+  const segment = findButton(host, label);
+  expect(segment).toBeDefined();
+  act(() => segment?.click());
+}
+
 function selectPreset(host: HTMLElement, presetId: string): string {
   const presetConfig = EASE_PRESETS.find((candidate) => candidate.id === presetId);
   if (!presetConfig) throw new Error(`Missing ease preset: ${presetId}`);
-
   const dropdown = host.querySelector<HTMLButtonElement>("[data-ease-type-dropdown]");
   expect(dropdown).not.toBeNull();
   act(() => dropdown?.click());
@@ -174,9 +179,7 @@ describe("AnimationCard", () => {
   it("tracks a committed segment ease alongside the existing update", () => {
     const onEaseCommit = vi.fn();
     const view = renderFocusCard(null, onEaseCommit, true);
-    const segment = findButton(view.host, "0% → 50%");
-    expect(segment).toBeDefined();
-    act(() => segment?.click());
+    openSegment(view.host, "0% → 50%");
     const ease = selectPreset(view.host, "quad-out");
 
     expect(onEaseCommit).toHaveBeenCalledWith(ANIMATION.id, 50, ease);
@@ -221,7 +224,6 @@ describe("AnimationCard", () => {
       vi.fn(),
       onUpdateSegmentEase,
     );
-
     const ease = selectPreset(view.host, "quad-out");
 
     expect(onUpdateKeyframeEase).toHaveBeenCalledExactlyOnceWith(ANIMATION.id, 50, ease);
@@ -258,7 +260,40 @@ function baseAnimation(overrides: Partial<GsapAnimation> = {}): GsapAnimation {
     ...overrides,
   } as GsapAnimation;
 }
+
 describe("AnimationCard ease editing", () => {
+  it.each([
+    ["spring", "power2.out", "spring(0.42)", "Spring bounce"],
+    ["wiggle", "power2.out", "wiggle(3,easeInOut,0.12)", "Wiggle count"],
+    ["curve", "spring(0.6)", "custom(M0,0 C0.16,1 0.3,1 1,1)", "Cubic bezier control points"],
+  ] as const)(
+    "commits and immediately displays the %s default when a keyframe segment switches mode",
+    (mode, currentEase, ease, fieldLabel) => {
+      const onUpdateKeyframeEase = vi.fn();
+      const animation = baseAnimation({
+        keyframes: {
+          format: "percentage",
+          keyframes: [
+            { percentage: 0, properties: { opacity: 0 } },
+            { percentage: 50, properties: { opacity: 0.5 }, ease: currentEase },
+            { percentage: 100, properties: { opacity: 1 } },
+          ],
+        },
+      });
+      const view = renderFocusCard(null, onUpdateKeyframeEase, true, animation);
+
+      openSegment(view.host, "0% → 50%");
+      const modeButton = view.host.querySelector<HTMLButtonElement>(`[data-ease-mode="${mode}"]`);
+      expect(modeButton).not.toBeNull();
+      act(() => modeButton?.click());
+
+      expect(onUpdateKeyframeEase).toHaveBeenCalledExactlyOnceWith(animation.id, 50, ease);
+      expect(modeButton?.getAttribute("aria-checked")).toBe("true");
+      expect(view.host.querySelector(`[aria-label="${fieldLabel}"]`)).not.toBeNull();
+      act(() => view.root.unmount());
+    },
+  );
+
   it("commits one preset change to the selected keyframe segment", () => {
     const onUpdateKeyframeEase = vi.fn();
     const animation = baseAnimation({
@@ -273,11 +308,7 @@ describe("AnimationCard ease editing", () => {
     });
     const view = renderCard({ animation, onUpdateKeyframeEase });
 
-    const segment = Array.from(view.host.querySelectorAll("button")).find((button) =>
-      button.textContent?.includes("0% → 50%"),
-    );
-    expect(segment).toBeDefined();
-    act(() => segment?.click());
+    openSegment(view.host, "0% → 50%");
     const ease = selectPreset(view.host, "quad-out");
 
     expect(onUpdateKeyframeEase).toHaveBeenCalledExactlyOnceWith(animation.id, 50, ease);

packages/studio/src/components/editor/EaseCurveSection.test.tsx

@@ -3,7 +3,10 @@
 import React, { act, useState } from "react";
 import { createRoot } from "react-dom/client";
 import { afterEach, describe, expect, it, vi } from "vitest";
+import { parseSpringBounce } from "@hyperframes/core/spring-ease";
+import { parseWiggleEase } from "@hyperframes/core/wiggle-ease";
 import { EaseCurveSection, MiniCurveSvg } from "./EaseCurveSection";
+import { resolveEaseCurveTuple } from "./gsapAnimationConstants";
 import type { AnimationKeyframeTarget } from "../../hooks/gsapTweenSynth";
 
 (globalThis as unknown as { IS_REACT_ACT_ENVIRONMENT: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
@@ -76,6 +79,19 @@ function renderStatefulSection(initialEase = "none", onCustomEaseCommit = vi.fn(
   return { host, root, onCustomEaseCommit };
 }
 
+function renderControlledSection(initialEase = "none", onCustomEaseCommit = vi.fn()) {
+  const host = document.createElement("div");
+  document.body.append(host);
+  const root = createRoot(host);
+  const renderEase = (ease: string) => {
+    act(() =>
+      root.render(<EaseCurveSection ease={ease} onCustomEaseCommit={onCustomEaseCommit} />),
+    );
+  };
+  renderEase(initialEase);
+  return { host, root, onCustomEaseCommit, renderEase };
+}
+
 function clickMode(host: HTMLElement, mode: "curve" | "spring" | "wiggle"): void {
   const toggle = host.querySelector<HTMLButtonElement>(`[data-ease-mode="${mode}"]`);
   expect(toggle).not.toBeNull();
@@ -291,12 +307,107 @@ describe("EaseCurveSection preset grid", () => {
 
     clickMode(host, "spring");
     expect(onCustomEaseCommit).toHaveBeenLastCalledWith("spring(0.42)");
+    expect(parseSpringBounce(onCustomEaseCommit.mock.lastCall![0])).toBe(0.42);
 
     clickMode(host, "curve");
     expect(onCustomEaseCommit).toHaveBeenLastCalledWith("custom(M0,0 C0.16,1 0.3,1 1,1)");
+    expect(resolveEaseCurveTuple(onCustomEaseCommit.mock.lastCall![0])).toEqual([0.16, 1, 0.3, 1]);
 
     clickMode(host, "wiggle");
     expect(onCustomEaseCommit).toHaveBeenLastCalledWith("wiggle(3,easeInOut,0.12)");
+    expect(parseWiggleEase(onCustomEaseCommit.mock.lastCall![0])).toEqual({
+      wiggles: 3,
+      type: "easeInOut",
+      amplitude: 0.12,
+    });
+    expect(onCustomEaseCommit).toHaveBeenCalledTimes(3);
+
+    act(() => root.unmount());
+  });
+
+  it("keeps an optimistic mode visible through its canonical prop round-trip", () => {
+    const { host, root, onCustomEaseCommit, renderEase } = renderControlledSection();
+
+    clickMode(host, "spring");
+    expect(host.querySelector('[data-ease-mode="spring"]')?.getAttribute("aria-checked")).toBe(
+      "true",
+    );
+    expect(host.querySelector('[aria-label="Spring bounce"]')).not.toBeNull();
+
+    renderEase("spring(0.42)");
+    expect(host.querySelector('[data-ease-mode="spring"]')?.getAttribute("aria-checked")).toBe(
+      "true",
+    );
+    expect(host.querySelector('[aria-label="Spring bounce"]')).not.toBeNull();
+    expect(onCustomEaseCommit).toHaveBeenCalledExactlyOnceWith("spring(0.42)");
+
+    act(() => root.unmount());
+  });
+
+  // Two switches before the first commit round-trips: the commits serialize, so
+  // the older value arrives while the newer one is still in flight. Repainting
+  // it would flash wiggle, spring, wiggle in the panel.
+  it("ignores an older in-flight commit arriving after a newer switch", () => {
+    const { host, root, renderEase } = renderControlledSection();
+
+    clickMode(host, "spring");
+    clickMode(host, "wiggle");
+    renderEase("spring(0.42)");
+
+    expect(host.querySelector('[data-ease-mode="wiggle"]')?.getAttribute("aria-checked")).toBe(
+      "true",
+    );
+
+    renderEase("wiggle(3,easeInOut,0.12)");
+    expect(host.querySelector('[data-ease-mode="wiggle"]')?.getAttribute("aria-checked")).toBe(
+      "true",
+    );
+
+    act(() => root.unmount());
+  });
+
+  // The commit is fire-and-forget: a rejected write or one that lands as a
+  // no-op never changes `ease`, so nothing else can retire the optimistic
+  // value and the panel would keep claiming a curve that was never saved.
+  it("falls back to the committed ease when the commit never round-trips", () => {
+    vi.useFakeTimers();
+    try {
+      const { host, root } = renderControlledSection("power2.out");
+
+      clickMode(host, "spring");
+      expect(host.querySelector('[data-ease-mode="spring"]')?.getAttribute("aria-checked")).toBe(
+        "true",
+      );
+
+      act(() => vi.advanceTimersByTime(2000));
+
+      expect(host.querySelector('[data-ease-mode="spring"]')?.getAttribute("aria-checked")).toBe(
+        "false",
+      );
+      expect(host.querySelector('[data-ease-mode="curve"]')?.getAttribute("aria-checked")).toBe(
+        "true",
+      );
+
+      act(() => root.unmount());
+    } finally {
+      vi.useRealTimers();
+    }
+  });
+
+  it("replaces an optimistic mode when the canonical prop changes externally", () => {
+    const { host, root, renderEase } = renderControlledSection();
+
+    clickMode(host, "spring");
+    renderEase("wiggle(2,uniform,0.3)");
+
+    expect(host.querySelector('[data-ease-mode="spring"]')?.getAttribute("aria-checked")).toBe(
+      "false",
+    );
+    expect(host.querySelector('[data-ease-mode="wiggle"]')?.getAttribute("aria-checked")).toBe(
+      "true",
+    );
+    expect(host.querySelector('[aria-label="Wiggle count"]')).not.toBeNull();
+    expect(host.querySelector('[aria-label="Spring bounce"]')).toBeNull();
 
     act(() => root.unmount());
   });