refactor(studio): share the flat-inspector test render harness across panel suites

The eight flat property-panel suites each carried an identical copy of the
React act-environment setup and a local renderInto() helper. Extract both into
testRenderUtils so the harness has one definition to fix.

No behavior change: setupReactActEnvironment() registers the same
document.body cleanup each file registered inline, and renderInto() is the
same createRoot + act wrapper.

Author: vanceingalls

packages/studio/src/components/editor/PropertyPanel.test.ts

@@ -8,11 +8,11 @@ import {
   getCssFilterFunctionPx,
   inferBoxShadowPreset,
   inferClipPathPreset,
+  isSelectedElementHidden,
   normalizePanelPxValue,
   parseInsetClipPathSides,
   setCssFilterFunctionPx,
-} from "./PropertyPanel";
-import { isSelectedElementHidden } from "./propertyPanelHelpers";
+} from "./propertyPanelHelpers";
 
 describe("PropertyPanel style helpers", () => {
   it("normalizes bounded pixel values without accepting incompatible units", () => {

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

@@ -1,26 +1,12 @@
 // @vitest-environment happy-dom
 
-import React, { act } from "react";
-import { createRoot } from "react-dom/client";
-import { afterEach, describe, expect, it, vi } from "vitest";
+import { act } from "react";
+import { describe, expect, it, vi } from "vitest";
 import { PropertyPanelEmptyState } from "./PropertyPanelEmptyState";
 import type { DomEditSelection } from "./domEditingTypes";
+import { renderInto, setupReactActEnvironment } from "./testRenderUtils";
 
-(globalThis as unknown as { IS_REACT_ACT_ENVIRONMENT: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
-
-afterEach(() => {
-  document.body.innerHTML = "";
-});
-
-function renderInto(node: React.ReactElement) {
-  const host = document.createElement("div");
-  document.body.append(host);
-  const root = createRoot(host);
-  act(() => {
-    root.render(node);
-  });
-  return { host, root };
-}
+setupReactActEnvironment();
 
 describe("PropertyPanelEmptyState — flat empty", () => {
   it("shows the cursor glyph, headline, and the two shortcut rows", () => {

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

@@ -1,8 +1,7 @@
 // @vitest-environment happy-dom
 
-import React, { act } from "react";
-import { createRoot } from "react-dom/client";
-import { afterEach, describe, expect, it, vi } from "vitest";
+import { act } from "react";
+import { describe, expect, it, vi } from "vitest";
 import {
   FlatColorGradingAccessory,
   FlatColorGradingSection,
@@ -11,22 +10,9 @@ import {
   normalizeHfColorGrading,
   type NormalizedHfColorGrading,
 } from "@hyperframes/core/color-grading";
+import { renderInto, setupReactActEnvironment } from "./testRenderUtils";
 
-(globalThis as unknown as { IS_REACT_ACT_ENVIRONMENT: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
-
-afterEach(() => {
-  document.body.innerHTML = "";
-});
-
-function renderInto(node: React.ReactElement) {
-  const host = document.createElement("div");
-  document.body.append(host);
-  const root = createRoot(host);
-  act(() => {
-    root.render(node);
-  });
-  return { host, root };
-}
+setupReactActEnvironment();
 
 function neutralGrading() {
   const grading = normalizeHfColorGrading("neutral");

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

@@ -1,31 +1,17 @@
 // @vitest-environment happy-dom
 
-import React, { act } from "react";
-import { createRoot } from "react-dom/client";
-import { afterEach, describe, expect, it, vi } from "vitest";
+import { act } from "react";
+import { describe, expect, it, vi } from "vitest";
 import {
   FlatLayoutSection,
   LayoutFlexBlock,
   LayoutGeometryRows,
   LayoutTransform3DBlock,
   LayoutZIndexRow,
 } from "./propertyPanelFlatLayoutSection";
+import { renderInto, setupReactActEnvironment } from "./testRenderUtils";
 
-(globalThis as unknown as { IS_REACT_ACT_ENVIRONMENT: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
-
-afterEach(() => {
-  document.body.innerHTML = "";
-});
-
-function renderInto(node: React.ReactElement) {
-  const host = document.createElement("div");
-  document.body.append(host);
-  const root = createRoot(host);
-  act(() => {
-    root.render(node);
-  });
-  return { host, root };
-}
+setupReactActEnvironment();
 
 function getFlatRowInput(host: HTMLElement, label: string): HTMLInputElement {
   const rows = Array.from(host.querySelectorAll<HTMLElement>(".group"));

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

@@ -1,16 +1,15 @@
 // @vitest-environment happy-dom
 
-import React, { act } from "react";
-import { createRoot } from "react-dom/client";
+import { act } from "react";
 import { afterEach, describe, expect, it, vi } from "vitest";
 import { FlatMotionSection, FlatTimingRow } from "./propertyPanelFlatMotionSection";
 import type { DomEditSelection } from "./domEditing";
 import { usePlayerStore } from "../../player";
+import { renderInto, setupReactActEnvironment } from "./testRenderUtils";
 
-(globalThis as unknown as { IS_REACT_ACT_ENVIRONMENT: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
+setupReactActEnvironment();
 
 afterEach(() => {
-  document.body.innerHTML = "";
   // The store is module-global, so a test that parks a focused ease segment
   // would otherwise leak it into every test that runs after it.
   usePlayerStore.getState().reset();
@@ -47,16 +46,6 @@ function baseElement(overrides: Partial<DomEditSelection> = {}): DomEditSelectio
   } as DomEditSelection;
 }
 
-function renderInto(node: React.ReactElement) {
-  const host = document.createElement("div");
-  document.body.append(host);
-  const root = createRoot(host);
-  act(() => {
-    root.render(node);
-  });
-  return { host, root };
-}
-
 describe("FlatTimingRow", () => {
   it("renders Start, End, and Duration from the element's data attributes", () => {
     const { host, root } = renderInto(

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

@@ -1,31 +1,17 @@
 // @vitest-environment happy-dom
 
 import React, { act } from "react";
-import { createRoot } from "react-dom/client";
-import { afterEach, describe, expect, it, vi } from "vitest";
+import { describe, expect, it, vi } from "vitest";
 import {
   FlatGroupHeader,
   FlatRow,
   FlatSegmentedRow,
   FlatSelectRow,
   FlatSlider,
 } from "./propertyPanelFlatPrimitives";
+import { renderInto, setupReactActEnvironment } from "./testRenderUtils";
 
-(globalThis as unknown as { IS_REACT_ACT_ENVIRONMENT: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
-
-afterEach(() => {
-  document.body.innerHTML = "";
-});
-
-function renderInto(node: React.ReactElement) {
-  const host = document.createElement("div");
-  document.body.append(host);
-  const root = createRoot(host);
-  act(() => {
-    root.render(node);
-  });
-  return { host, root };
-}
+setupReactActEnvironment();
 
 describe("FlatRow", () => {
   it("renders the default tier with no reset button", () => {

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

@@ -1,28 +1,15 @@
 // @vitest-environment happy-dom
 
-import React, { act, useState } from "react";
+import { act, useState } from "react";
 import { createRoot } from "react-dom/client";
 import postcss from "postcss";
 import tailwindcss from "tailwindcss";
-import { afterEach, describe, expect, it, vi } from "vitest";
+import { describe, expect, it, vi } from "vitest";
 import { FlatTextLayerList, FlatTextSection } from "./propertyPanelFlatTextSection";
 import type { DomEditSelection, DomEditTextField } from "./domEditingTypes";
+import { renderInto, setupReactActEnvironment } from "./testRenderUtils";
 
-(globalThis as unknown as { IS_REACT_ACT_ENVIRONMENT: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
-
-afterEach(() => {
-  document.body.innerHTML = "";
-});
-
-function renderInto(node: React.ReactElement) {
-  const host = document.createElement("div");
-  document.body.append(host);
-  const root = createRoot(host);
-  act(() => {
-    root.render(node);
-  });
-  return { host, root };
-}
+setupReactActEnvironment();
 
 const FIELDS = [
   {

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

@@ -1,25 +1,11 @@
 // @vitest-environment happy-dom
 
-import React, { act } from "react";
-import { createRoot } from "react-dom/client";
-import { afterEach, describe, expect, it, vi } from "vitest";
+import { act } from "react";
+import { describe, expect, it, vi } from "vitest";
 import { FlatToggle } from "./propertyPanelFlatToggle";
+import { renderInto, setupReactActEnvironment } from "./testRenderUtils";
 
-(globalThis as unknown as { IS_REACT_ACT_ENVIRONMENT: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
-
-afterEach(() => {
-  document.body.innerHTML = "";
-});
-
-function renderInto(node: React.ReactElement) {
-  const host = document.createElement("div");
-  document.body.append(host);
-  const root = createRoot(host);
-  act(() => {
-    root.render(node);
-  });
-  return { host, root };
-}
+setupReactActEnvironment();
 
 describe("FlatToggle", () => {
   it("renders the off state with a dim label and dim knob, and fires onChange(true) on click", () => {

packages/studio/src/components/editor/testRenderUtils.tsx

@@ -0,0 +1,26 @@
+import React, { act } from "react";
+import { createRoot } from "react-dom/client";
+import { afterEach } from "vitest";
+
+/**
+ * Marks the current environment as React-act-aware and registers the shared
+ * per-test DOM cleanup. Call once per test file, at module scope, before any
+ * `describe`/`it` blocks run.
+ */
+export function setupReactActEnvironment(): void {
+  (globalThis as unknown as { IS_REACT_ACT_ENVIRONMENT: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
+
+  afterEach(() => {
+    document.body.innerHTML = "";
+  });
+}
+
+export function renderInto(node: React.ReactElement) {
+  const host = document.createElement("div");
+  document.body.append(host);
+  const root = createRoot(host);
+  act(() => {
+    root.render(node);
+  });
+  return { host, root };
+}