[TextField] Migrate FormHelperText to emotion

docs/pages/api-docs/form-helper-text.json

@@ -9,6 +9,7 @@
     "focused": { "type": { "name": "bool" } },
     "margin": { "type": { "name": "enum", "description": "'dense'" } },
     "required": { "type": { "name": "bool" } },
+    "sx": { "type": { "name": "object" } },
     "variant": {
       "type": {
         "name": "enum",
@@ -41,6 +42,6 @@
   "filename": "/packages/material-ui/src/FormHelperText/FormHelperText.js",
   "inheritance": null,
   "demos": "<ul><li><a href=\"/components/text-fields/\">Text Fields</a></li></ul>",
-  "styledComponent": false,
+  "styledComponent": true,
   "cssComponent": false
 }

docs/translations/api-docs/form-helper-text/form-helper-text.json

@@ -10,6 +10,7 @@
     "focused": "If <code>true</code>, the helper text should use focused classes key.",
     "margin": "If <code>dense</code>, will adjust vertical spacing. This is normally obtained via context from FormControl.",
     "required": "If <code>true</code>, the helper text should use required classes key.",
+    "sx": "The system prop that allows defining system overrides as well as additional CSS styles. See the <a href=\"/system/basics/#the-sx-prop\">`sx` page</a> for more details.",
     "variant": "The variant to use."
   },
   "classDescriptions": {

packages/material-ui/src/FormHelperText/FormHelperText.d.ts

@@ -1,5 +1,7 @@
 import * as React from 'react';
+import { SxProps } from '@material-ui/system';
 import { OverridableComponent, OverrideProps } from '../OverridableComponent';
+import { Theme } from '../styles';
 
 export interface FormHelperTextTypeMap<P = {}, D extends React.ElementType = 'p'> {
   props: P & {
@@ -55,6 +57,10 @@ export interface FormHelperTextTypeMap<P = {}, D extends React.ElementType = 'p'
      * If `true`, the helper text should use required classes key.
      */
     required?: boolean;
+    /**
+     * The system prop that allows defining system overrides as well as additional CSS styles.
+     */
+    sx?: SxProps<Theme>;
     /**
      * The variant to use.
      */

packages/material-ui/src/FormHelperText/FormHelperText.js

@@ -1,52 +1,76 @@
 import * as React from 'react';
 import PropTypes from 'prop-types';
 import clsx from 'clsx';
+import { unstable_composeClasses as composeClasses } from '@material-ui/unstyled';
+import { deepmerge } from '@material-ui/utils';
 import formControlState from '../FormControl/formControlState';
 import useFormControl from '../FormControl/useFormControl';
-import withStyles from '../styles/withStyles';
+import experimentalStyled from '../styles/experimentalStyled';
+import capitalize from '../utils/capitalize';
+import { getFormHelperTextUtilityClasses } from './formHelperTextClasses';
+import useThemeProps from '../styles/useThemeProps';
 
-export const styles = (theme) => ({
-  /* Styles applied to the root element. */
-  root: {
-    color: theme.palette.text.secondary,
-    ...theme.typography.caption,
-    textAlign: 'left',
-    marginTop: 3,
-    margin: 0,
-    '&$disabled': {
-      color: theme.palette.text.disabled,
-    },
-    '&$error': {
-      color: theme.palette.error.main,
-    },
+const overridesResolver = (props, styles) => {
+  const { styleProps } = props;
+
+  return deepmerge(styles.root || {}, {
+    ...(styleProps.size && styles[`size${capitalize(styleProps.size)}`]),
+    ...(styleProps.contained && styles.contained),
+    ...(styleProps.filled && styles.filled),
+  });
+};
+
+const useUtilityClasses = (styleProps) => {
+  const { classes, contained, size, disabled, error, filled, focused, required } = styleProps;
+  const slots = {
+    root: [
+      'root',
+      disabled && 'disabled',
+      error && 'error',
+      size && `size${capitalize(size)}`,
+      contained && 'contained',
+      focused && 'focused',
+      filled && 'filled',
+      required && 'required',
+    ],
+  };
+
+  return composeClasses(slots, getFormHelperTextUtilityClasses, classes);
+};
+
+const FormHelperTextRoot = experimentalStyled(
+  'p',
+  {},
+  { name: 'MuiFormHelperText', slot: 'Root', overridesResolver },
+)(({ theme, styleProps }) => ({
+  color: theme.palette.text.secondary,
+  ...theme.typography.caption,
+  textAlign: 'left',
+  marginTop: 3,
+  marginRight: 0,
+  marginBottom: 0,
+  marginLeft: 0,
+  '&.Mui-disabled': {
+    color: theme.palette.text.disabled,
   },
-  /* Pseudo-class applied to the root element if `error={true}`. */
-  error: {},
-  /* Pseudo-class applied to the root element if `disabled={true}`. */
-  disabled: {},
-  /* Styles applied to the root element if `size="small"`. */
-  sizeSmall: {
-    marginTop: 4,
+  '&.Mui-error': {
+    color: theme.palette.error.main,
   },
-  /* Styles applied to the root element if `variant="filled"` or `variant="outlined"`. */
-  contained: {
+  ...(styleProps.size === 'small' && {
+    marginTop: 4,
+  }),
+  ...(styleProps.contained && {
     marginLeft: 14,
     marginRight: 14,
-  },
-  /* Pseudo-class applied to the root element if `focused={true}`. */
-  focused: {},
-  /* Pseudo-class applied to the root element if `filled={true}`. */
-  filled: {},
-  /* Pseudo-class applied to the root element if `required={true}`. */
-  required: {},
-});
+  }),
+}));
 
-const FormHelperText = React.forwardRef(function FormHelperText(props, ref) {
+const FormHelperText = React.forwardRef(function FormHelperText(inProps, ref) {
+  const props = useThemeProps({ props: inProps, name: 'MuiFormHelperText' });
   const {
     children,
-    classes,
     className,
-    component: Component = 'p',
+    component = 'p',
     disabled,
     error,
     filled,
@@ -64,21 +88,26 @@ const FormHelperText = React.forwardRef(function FormHelperText(props, ref) {
     states: ['variant', 'size', 'disabled', 'error', 'filled', 'focused', 'required'],
   });
 
+  const styleProps = {
+    ...props,
+    component,
+    contained: fcs.variant === 'filled' || fcs.variant === 'outlined',
+    variant: fcs.variant,
+    size: fcs.size,
+    disabled: fcs.disabled,
+    error: fcs.error,
+    filled: fcs.filled,
+    focused: fcs.focused,
+    required: fcs.required,
+  };
+
+  const classes = useUtilityClasses(styleProps);
+
   return (
-    <Component
-      className={clsx(
-        classes.root,
-        {
-          [classes.contained]: fcs.variant === 'filled' || fcs.variant === 'outlined',
-          [classes.sizeSmall]: fcs.size === 'small',
-          [classes.disabled]: fcs.disabled,
-          [classes.error]: fcs.error,
-          [classes.filled]: fcs.filled,
-          [classes.focused]: fcs.focused,
-          [classes.required]: fcs.required,
-        },
-        className,
-      )}
+    <FormHelperTextRoot
+      as={component}
+      styleProps={styleProps}
+      className={clsx(classes.root, className)}
       ref={ref}
       {...other}
     >
@@ -89,7 +118,7 @@ const FormHelperText = React.forwardRef(function FormHelperText(props, ref) {
       ) : (
         children
       )}
-    </Component>
+    </FormHelperTextRoot>
   );
 });
 
@@ -142,10 +171,14 @@ FormHelperText.propTypes = {
    * If `true`, the helper text should use required classes key.
    */
   required: PropTypes.bool,
+  /**
+   * The system prop that allows defining system overrides as well as additional CSS styles.
+   */
+  sx: PropTypes.object,
   /**
    * The variant to use.
    */
   variant: PropTypes.oneOf(['filled', 'outlined', 'standard']),
 };
 
-export default withStyles(styles, { name: 'MuiFormHelperText' })(FormHelperText);
+export default FormHelperText;

packages/material-ui/src/FormHelperText/FormHelperText.test.js

@@ -1,24 +1,23 @@
 import * as React from 'react';
 import { expect } from 'chai';
-import { getClasses, createMount, createClientRender, describeConformance } from 'test/utils';
+import { createMount, createClientRender, describeConformanceV5 } from 'test/utils';
 import FormHelperText from './FormHelperText';
 import FormControl from '../FormControl';
+import classes from './formHelperTextClasses';
 
 describe('<FormHelperText />', () => {
   const mount = createMount();
   const render = createClientRender();
-  let classes;
 
-  before(() => {
-    classes = getClasses(<FormHelperText />);
-  });
-
-  describeConformance(<FormHelperText />, () => ({
+  describeConformanceV5(<FormHelperText />, () => ({
     classes,
     inheritComponent: 'p',
     mount,
     refInstanceof: window.HTMLParagraphElement,
     testComponentPropWith: 'div',
+    muiName: 'MuiFormHelperText',
+    testVariantProps: { size: 'small' },
+    skip: ['componentsProp'],
   }));
 
   describe('prop: error', () => {

packages/material-ui/src/FormHelperText/formHelperTextClasses.d.ts

@@ -0,0 +1,17 @@
+export interface FormHelperTextClasses {
+  root: string;
+  error: string;
+  disabled: string;
+  sizeSmall: string;
+  sizeMedium: string;
+  contained: string;
+  focused: string;
+  filled: string;
+  required: string;
+}
+
+declare const formHelperTextClasses: FormHelperTextClasses;
+
+export function getFormHelperTextUtilityClasses(slot: string): string;
+
+export default formHelperTextClasses;

packages/material-ui/src/FormHelperText/formHelperTextClasses.js

@@ -0,0 +1,19 @@
+import { generateUtilityClass, generateUtilityClasses } from '@material-ui/unstyled';
+
+export function getFormHelperTextUtilityClasses(slot) {
+  return generateUtilityClass('MuiFormHelperText', slot);
+}
+
+const formHelperTextClasses = generateUtilityClasses('MuiFormHelperText', [
+  'root',
+  'error',
+  'disabled',
+  'sizeSmall',
+  'sizeMedium',
+  'contained',
+  'focused',
+  'filled',
+  'required',
+]);
+
+export default formHelperTextClasses;

packages/material-ui/src/FormHelperText/index.d.ts

@@ -1,2 +1,5 @@
 export { default } from './FormHelperText';
 export * from './FormHelperText';
+
+export { default as formHelperTextClasses } from './formHelperTextClasses';
+export * from './formHelperTextClasses';

packages/material-ui/src/FormHelperText/index.js

@@ -1 +1,4 @@
 export { default } from './FormHelperText';
+
+export { default as formHelperTextClasses } from './formHelperTextClasses';
+export * from './formHelperTextClasses';