fix: aria-live and aria-describedby on fieldset element.

Author: m-maillot

src/shared/Fieldset.tsx

@@ -1,10 +1,10 @@
 import React, {
-    useId,
-    memo,
+    type ComponentProps,
+    type CSSProperties,
     forwardRef,
+    memo,
     type ReactNode,
-    type CSSProperties,
-    type ComponentProps
+    useId
 } from "react";
 import { symToStr } from "tsafe/symToStr";
 import { assert } from "tsafe/assert";
@@ -96,8 +96,7 @@ export const Fieldset = memo(
 
         const legendId = `${id}-legend`;
 
-        const errorDescId = `${id}-desc-error`;
-        const successDescId = `${id}-desc-valid`;
+        const messageId = `${id}-desc`;
         const messagesWrapperId = `${id}-messages`;
 
         const radioName = (function useClosure() {
@@ -184,6 +183,7 @@ export const Fieldset = memo(
                             fr.cx("fr-fieldset__legend", "fr-text--regular"),
                             classes.legend
                         )}
+                        aria-describedby={state !== "default" ? messageId : undefined}
                     >
                         {legend}
                         {hintText !== undefined && (
@@ -197,18 +197,11 @@ export const Fieldset = memo(
                 <div
                     className={fr.cx("fr-messages-group")}
                     id={messagesWrapperId}
-                    aria-live="assertive"
+                    aria-live={state === "error" ? "assertive" : undefined}
                 >
                     {stateRelatedMessage !== undefined && (
                         <p
-                            id={(() => {
-                                switch (state) {
-                                    case "error":
-                                        return errorDescId;
-                                    case "success":
-                                        return successDescId;
-                                }
-                            })()}
+                            id={messageId}
                             className={fr.cx(
                                 "fr-message",
                                 (() => {