[Snackbar] Remove RTL direction specific logic (#32808)

packages/mui-material/src/Snackbar/Snackbar.js

@@ -42,16 +42,9 @@ const SnackbarRoot = styled('div', {
   },
 })(({ theme, ownerState }) => {
   const center = {
-    ...(!ownerState.isRtl && {
-      left: '50%',
-      right: 'auto',
-      transform: 'translateX(-50%)',
-    }),
-    ...(ownerState.isRtl && {
-      right: '50%',
-      left: 'auto',
-      transform: 'translateX(50%)',
-    }),
+    left: '50%',
+    right: 'auto',
+    transform: 'translateX(-50%)',
   };
 
   return {
@@ -69,24 +62,12 @@ const SnackbarRoot = styled('div', {
       ...(ownerState.anchorOrigin.vertical === 'top' ? { top: 24 } : { bottom: 24 }),
       ...(ownerState.anchorOrigin.horizontal === 'center' && center),
       ...(ownerState.anchorOrigin.horizontal === 'left' && {
-        ...(!ownerState.isRtl && {
-          left: 24,
-          right: 'auto',
-        }),
-        ...(ownerState.isRtl && {
-          right: 24,
-          left: 'auto',
-        }),
+        left: 24,
+        right: 'auto',
       }),
       ...(ownerState.anchorOrigin.horizontal === 'right' && {
-        ...(!ownerState.isRtl && {
-          right: 24,
-          left: 'auto',
-        }),
-        ...(ownerState.isRtl && {
-          left: 24,
-          right: 'auto',
-        }),
+        right: 24,
+        left: 'auto',
       }),
     },
   };
@@ -123,9 +104,7 @@ const Snackbar = React.forwardRef(function Snackbar(inProps, ref) {
     ...other
   } = props;
 
-  const isRtl = theme.direction === 'rtl';
-
-  const ownerState = { ...props, anchorOrigin: { vertical, horizontal }, isRtl };
+  const ownerState = { ...props, anchorOrigin: { vertical, horizontal } };
   const classes = useUtilityClasses(ownerState);
 
   const timerAutoHide = React.useRef();

test/regressions/fixtures/Snackbar/PositionedSnackbar.js

@@ -0,0 +1,22 @@
+import * as React from 'react';
+import Box from '@mui/material/Box';
+import Snackbar from '@mui/material/Snackbar';
+
+export default function PositionedSnackbar() {
+  return (
+    <Box dir="ltr" sx={{ width: window?.innerWidth, height: '100vh' }}>
+      <Snackbar
+        key="left"
+        anchorOrigin={{ horizontal: 'left', vertical: 'bottom' }}
+        message="Snackbar should show left (LTR)"
+        open
+      />
+      <Snackbar
+        key="right"
+        anchorOrigin={{ horizontal: 'right', vertical: 'top' }}
+        message="Snackbar should show right (LTR)"
+        open
+      />
+    </Box>
+  );
+}

test/regressions/fixtures/Snackbar/PositionedSnackbarRtl.js

@@ -0,0 +1,43 @@
+import * as React from 'react';
+import Box from '@mui/material/Box';
+import { prefixer } from 'stylis';
+import rtlPlugin from 'stylis-plugin-rtl';
+import rtlPluginSc from 'stylis-plugin-rtl-sc';
+import { StyleSheetManager } from 'styled-components';
+import { CacheProvider } from '@emotion/react';
+import { createTheme, ThemeProvider } from '@mui/material/styles';
+import createCache from '@emotion/cache';
+import Snackbar from '@mui/material/Snackbar';
+
+// Create rtl cache
+const cacheRtl = createCache({
+  key: 'muirtl',
+  stylisPlugins: [prefixer, rtlPlugin],
+});
+
+const theme = createTheme({ direction: 'rtl' });
+
+export default function PositionedSnackbar() {
+  return (
+    <StyleSheetManager stylisPlugins={[rtlPluginSc]}>
+      <CacheProvider value={cacheRtl}>
+        <ThemeProvider theme={theme}>
+          <Box dir="rtl" sx={{ width: window?.innerWidth, height: '100vh' }}>
+            <Snackbar
+              key="left"
+              anchorOrigin={{ horizontal: 'left', vertical: 'bottom' }}
+              message="Snackbar should show right (RTL)"
+              open
+            />
+            <Snackbar
+              key="right"
+              anchorOrigin={{ horizontal: 'right', vertical: 'top' }}
+              message="Snackbar should show left (RTL)"
+              open
+            />
+          </Box>
+        </ThemeProvider>
+      </CacheProvider>
+    </StyleSheetManager>
+  );
+}