fix: ensure multi-action and split button children container is not hidden by parent overflow

src/components/accordion/accordion-test.stories.tsx

@@ -3,10 +3,13 @@ import { action } from "@storybook/addon-actions";
 import { Accordion, AccordionGroup } from ".";
 import Textbox from "../textbox";
 import Box from "../box";
+import MultiActionButton from "../multi-action-button";
+import SplitButton from "../split-button";
+import Button from "../button/button.component";
 
 export default {
   title: "Accordion/Test",
-  includeStories: ["Default", "Grouped"],
+  includeStories: ["Default", "Grouped", "AccordionWithMultiAction"],
   parameters: {
     info: { disable: true },
     chromatic: {
@@ -112,3 +115,27 @@ export const Grouped = ({ ...args }) => (
 );
 
 Grouped.storyName = "grouped";
+
+export const AccordionWithMultiAction = () => {
+  return (
+    <Accordion title="Accordion">
+      <MultiActionButton text="Multi Action Button">
+        <Button>Button 1</Button>
+        <Button>Button 2</Button>
+        <Button>Button 3</Button>
+        <Button>Button 4</Button>
+        <Button>Button 5</Button>
+      </MultiActionButton>
+      <SplitButton text="Split Button">
+        <Button>Button 1</Button>
+        <Button>Button 2</Button>
+        <Button>Button 3</Button>
+        <Button>Button 4</Button>
+        <Button>Button 5</Button>
+      </SplitButton>
+    </Accordion>
+  );
+};
+
+AccordionWithMultiAction.storyName =
+  "Accordion with MultiAction and Split Button";

src/components/accordion/accordion.pw.tsx

@@ -38,13 +38,16 @@
   AccordionGroupDefault,
   AccordionGroupValidation,
   AccordionWithDefinitionList,
+  AccordionWithSplit,
 } from "./components.test-pw";
 
+import { additionalButton as splitAdditionalButtons } from "../../../playwright/components/split-button";
+
 const testData = [CHARACTERS.DIACRITICS, CHARACTERS.SPECIALCHARACTERS];
 
 test.describe("when focused", () => {
   // TODO: Skipped due to flaky focus behaviour. To review in FE-6428
   test.skip("should have the expected styling when the focusRedesignOptOut is false", async ({
     mount,
     page,
   }) => {
@@ -63,7 +66,7 @@
   });
 
   // TODO: Skipped due to flaky focus behaviour. To review in FE-6428
   test.skip("should have the expected styling when the focusRedesignOptOut is true", async ({
     mount,
     page,
   }) => {
@@ -455,6 +458,21 @@
     await expect(accordionTitleContainer(page)).toContainText("subtle");
     await expect(accordionTitleContainer(page)).not.toContainText("subtitle");
   });
+
+  test("should not hide the children container of SplitButton when it opens", async ({
+    mount,
+    page,
+  }) => {
+    await mount(<AccordionWithSplit />);
+
+    await getDataElementByValue(page, "dropdown").click();
+
+    await expect(splitAdditionalButtons(page, 0)).toBeVisible();
+    await expect(splitAdditionalButtons(page, 1)).toBeVisible();
+    await expect(splitAdditionalButtons(page, 2)).toBeVisible();
+    await expect(splitAdditionalButtons(page, 3)).toBeVisible();
+    await expect(splitAdditionalButtons(page, 4)).toBeVisible();
+  });
 });
 
 test.describe("should render Accordion Grouped component", () => {

src/components/accordion/components.test-pw.tsx

@@ -6,6 +6,7 @@ import Button from "../button/button.component";
 import { Checkbox } from "../checkbox";
 import { Dl, Dt, Dd } from "../definition-list";
 import Link from "../link/link.component";
+import SplitButton from "../split-button";
 
 const errorVal = "error";
 const warningVal = "warning";
@@ -550,3 +551,17 @@ export const AccordionWithDefinitionList = () => {
     </Accordion>
   );
 };
+
+export const AccordionWithSplit = () => {
+  return (
+    <Accordion expanded title="Accordion">
+      <SplitButton text="Split Button">
+        <Button>Button 1</Button>
+        <Button>Button 2</Button>
+        <Button>Button 3</Button>
+        <Button>Button 4</Button>
+        <Button>Button 5</Button>
+      </SplitButton>
+    </Accordion>
+  );
+};

src/components/multi-action-button/multi-action-button.component.tsx

@@ -86,6 +86,7 @@ export const MultiActionButton = ({
           : /* istanbul ignore next */ "bottom-end"
       }
       reference={buttonNode}
+      popoverStrategy="fixed"
       middleware={[
         offset(6),
         flip({

src/components/multi-action-button/multi-action-button.pw.tsx

@@ -107,8 +107,8 @@ test.describe("Prop tests", () => {
 
   (
     [
-      ["left", 0],
-      ["right", -46],
+      ["left", 198],
+      ["right", 152],
     ] as [MultiActionButtonProps["position"], number][]
   ).forEach(([position, value]) => {
     test(`should render with menu position to the ${position}`, async ({
@@ -120,7 +120,7 @@ test.describe("Prop tests", () => {
       const actionButton = getComponent(page, "multi-action-button");
       await actionButton.click();
       const listContainer = getDataElementByValue(page, "additional-buttons");
-      await expect(listContainer).toHaveCSS("position", "absolute");
+      await expect(listContainer).toHaveCSS("position", "fixed");
       await assertCssValueIsApproximately(listContainer, "top", 46);
       await assertCssValueIsApproximately(listContainer, "left", value);
     });

src/components/split-button/split-button.component.tsx

@@ -182,6 +182,7 @@ export const SplitButton = ({
             ? /* istanbul ignore next */ "bottom-start"
             : "bottom-end"
         }
+        popoverStrategy="fixed"
         reference={buttonNode}
         middleware={[
           offset(6),

src/components/split-button/split-button.pw.tsx

@@ -264,8 +264,8 @@ test.describe("Prop tests", () => {
 
   (
     [
-      ["left", 0],
-      ["right", 42],
+      ["left", 198],
+      ["right", 242],
     ] as [SplitButtonProps["position"], number][]
   ).forEach(([position, value]) => {
     test(`should render with menu position to the ${position}`, async ({
@@ -276,7 +276,7 @@ test.describe("Prop tests", () => {
 
       await getDataElementByValue(page, "dropdown").click();
       const listContainer = additionalButtonsContainer(page);
-      await expect(listContainer).toHaveCSS("position", "absolute");
+      await expect(listContainer).toHaveCSS("position", "fixed");
       await assertCssValueIsApproximately(listContainer, "top", 46);
       await assertCssValueIsApproximately(listContainer, "left", value);
     });