[ui][text input] add description prop

apps/storybook/stories/text-input.stories.tsx

@@ -12,6 +12,9 @@ export default {
     autoComplete: {
       control: 'text',
     },
+    description: {
+      control: 'text',
+    },
     disabled: {
       control: 'boolean',
     },
@@ -183,6 +186,25 @@ export function Error() {
   );
 }
 
+export function Description() {
+  const [value, setValue] = useState('1234567');
+
+  return (
+    <TextInput
+      description="Select a password that is at least 6 characters"
+      errorMessage={
+        value.length < 6 ? 'Password must be at least 6 characters' : undefined
+      }
+      label="Password"
+      startAddOn={KeyIcon}
+      startAddOnType="icon"
+      type="password"
+      value={value}
+      onChange={setValue}
+    />
+  );
+}
+
 export function AddOns() {
   return (
     <div className="space-y-4">

packages/ui/src/TextInput/TextInput.tsx

@@ -62,6 +62,7 @@ type EndAddOnProps =
 
 type BaseProps = Readonly<{
   defaultValue?: string;
+  description?: React.ReactNode;
   endIcon?: React.ComponentType<React.ComponentProps<'svg'>>;
   errorMessage?: React.ReactNode;
   id?: string;
@@ -99,6 +100,7 @@ const stateClasses: Record<
 function TextInput(
   {
     defaultValue,
+    description,
     disabled,
     endAddOn,
     endAddOnType,
@@ -119,7 +121,7 @@ function TextInput(
   const hasError = errorMessage != null;
   const generatedId = useId();
   const id = idParam ?? generatedId;
-  const errorId = useId();
+  const messageId = useId();
   const state: State = hasError ? 'error' : 'normal';
   const { input: inputClass, container: containerClass } = stateClasses[state];
 
@@ -175,7 +177,9 @@ function TextInput(
         })()}
         <input
           ref={ref}
-          aria-describedby={hasError ? errorId : undefined}
+          aria-describedby={
+            hasError || description != null ? messageId : undefined
+          }
           aria-invalid={hasError ? true : undefined}
           className={clsx(
             'w-0 flex-1 border-none text-sm focus:outline-none focus:ring-0 disabled:cursor-not-allowed disabled:bg-transparent disabled:text-slate-500',
@@ -224,9 +228,14 @@ function TextInput(
           }
         })()}
       </div>
-      {errorMessage && (
-        <p className="text-danger-600 mt-2 text-sm" id={errorId}>
-          {errorMessage}
+      {(errorMessage ?? description) && (
+        <p
+          className={clsx(
+            'mt-2 text-sm',
+            errorMessage ? 'text-danger-600' : 'text-slate-500',
+          )}
+          id={messageId}>
+          {errorMessage ?? description}
         </p>
       )}
     </div>