[material-ui][Select] Fix variant type

packages/mui-material/src/Select/Select.d.ts

@@ -148,7 +148,7 @@ export interface BaseSelectProps<Value = unknown>
    * The variant to use.
    * @default 'outlined'
    */
-  variant?: 'filled' | 'standard' | 'outlined';
+  variant?: SelectVariants;
 }
 
 export interface FilledSelectProps extends Omit<FilledInputProps, 'value' | 'onChange'> {
@@ -172,20 +172,15 @@ export interface OutlinedSelectProps extends Omit<OutlinedInputProps, 'value' |
    * The variant to use.
    * @default 'outlined'
    */
-  variant: 'outlined';
+  variant?: 'outlined';
 }
 
 export type SelectVariants = 'outlined' | 'standard' | 'filled';
 
-export type SelectProps<
-  Value = unknown,
-  Variant extends SelectVariants = SelectVariants,
-> = BaseSelectProps<Value> &
-  (Variant extends 'filled'
-    ? FilledSelectProps
-    : Variant extends 'standard'
-      ? StandardSelectProps
-      : OutlinedSelectProps);
+export type SelectProps<Value = unknown> =
+  | (FilledSelectProps & BaseSelectProps<Value>)
+  | (StandardSelectProps & BaseSelectProps<Value>)
+  | (OutlinedSelectProps & BaseSelectProps<Value>);
 
 /**
  *
@@ -198,15 +193,8 @@ export type SelectProps<
  * - [Select API](https://mui.com/material-ui/api/select/)
  * - inherits [OutlinedInput API](https://mui.com/material-ui/api/outlined-input/)
  */
-
-export default function Select<Value = unknown, Variant extends SelectVariants = 'outlined'>(
-  props: {
-    /**
-     * The variant to use.
-     * @default 'outlined'
-     */
-    variant?: Variant;
-  } & Omit<SelectProps<Value, Variant>, 'variant'>,
+export default function Select<Value = unknown>(
+  props: SelectProps<Value>,
 ): JSX.Element & {
   muiName: string;
 };

packages/mui-material/src/Select/Select.spec.tsx

@@ -1,5 +1,5 @@
 import * as React from 'react';
-import Select, { SelectChangeEvent } from '@mui/material/Select';
+import Select, { SelectChangeEvent, SelectProps } from '@mui/material/Select';
 import MenuItem from '@mui/material/MenuItem';
 import { createTheme } from '@mui/material/styles';
 
@@ -75,4 +75,124 @@ function genericValueTest() {
       },
     }}
   />;
+
+  <Select variant="filled" />;
+  <Select variant="standard" />;
+  <Select variant="outlined" />;
+  <Select />;
+
+  <Select variant="filled" hiddenLabel />;
+  // @ts-expect-error hiddenLabel is not present in standard variant
+  <Select variant="standard" hiddenLabel />;
+  // @ts-expect-error hiddenLabel is not present in outlined variant
+  <Select variant="outlined" hiddenLabel />;
+  // @ts-expect-error hiddenLabel is not present in outlined variant
+  <Select hiddenLabel />;
+
+  const defaultProps: SelectProps<number> = {};
+  const outlinedProps: SelectProps<number> = {
+    variant: 'outlined',
+  };
+  const filledProps: SelectProps<number> = {
+    variant: 'filled',
+  };
+  const standardProps: SelectProps<number> = {
+    variant: 'standard',
+  };
+
+  <Select {...defaultProps} />;
+  <Select {...outlinedProps} />;
+  <Select {...filledProps} />;
+  <Select {...standardProps} />;
+  <Select<number> {...outlinedProps} />;
+  <Select<number> {...defaultProps} />;
+  <Select<number> {...filledProps} />;
+
+  const rawDefaultProps: SelectProps = {};
+  const rawOutlinedProps: SelectProps = {
+    variant: 'outlined',
+  };
+  const rawFilledProps: SelectProps = {
+    variant: 'filled',
+  };
+
+  <Select {...rawDefaultProps} />;
+  <Select {...rawOutlinedProps} />;
+  <Select {...rawFilledProps} />;
+
+  // @ts-expect-error hiddenLabel is not present in outlined variant
+  <Select {...defaultProps} hiddenLabel />;
+  // @ts-expect-error hiddenLabel is not present in outlined variant
+  <Select {...outlinedProps} hiddenLabel />;
+  <Select {...filledProps} hiddenLabel />;
+  // @ts-expect-error hiddenLabel is not present in standard variant
+  <Select {...standardProps} hiddenLabel />;
+
+  interface OtherProps {
+    otherProp?: number;
+  }
+
+  const SelectWrapper1 = <Value,>(props: SelectProps<Value> & OtherProps) => {
+    const { otherProp, ...materialSelectProps } = props;
+
+    return <Select<Value> {...materialSelectProps} />;
+  };
+
+  <SelectWrapper1 />;
+  <SelectWrapper1<number> variant="filled" hiddenLabel />;
+  <SelectWrapper1 variant="filled" hiddenLabel />;
 }
+
+type Options<T> = { text: string; value: T } | T;
+
+type Props<T> = (
+  | {
+      value: T;
+      multiple?: false;
+      onChange: (value: T) => void;
+    }
+  | {
+      value: T[];
+      multiple: true;
+      onChange: (value: T[]) => void;
+    }
+) & {
+  options: Options<T>[];
+};
+
+// test for https://github.com/mui/material-ui/issues/41375
+const AppSelect = <T extends string>(props: Props<T>) => {
+  const getOptionText = (option: Options<T>) => {
+    if (typeof option === 'object') {
+      return option.text;
+    }
+    return option;
+  };
+
+  const getOptionValue = (option: Options<T>) => {
+    if (typeof option === 'object') {
+      return option.value;
+    }
+    return option;
+  };
+
+  return (
+    <Select
+      value={props.value}
+      multiple={props.multiple}
+      onChange={(event) => {
+        if (props.multiple) {
+          props.onChange(event.target.value as T[]);
+        } else {
+          props.onChange(event.target.value as T);
+        }
+      }}
+    >
+      {props.options.map((option, index) => (
+        <MenuItem key={index} value={getOptionValue(option)}>
+          {getOptionText(option)}
+        </MenuItem>
+      ))}
+    </Select>
+  );
+};