perf: defer styles computation from module import to provider render

Author: BartekObudzinski

src/components/ThemeStylesContextProvider/default.ts

@@ -1,15 +1,34 @@
-// eslint-disable-next-line no-restricted-imports
-import {defaultStyles} from '@styles/index';
-// eslint-disable-next-line no-restricted-imports
-import {DefaultStyleUtils} from '@styles/utils';
+import styles from '@src/styles';
+import {defaultTheme} from '@src/styles/theme';
+import createStyleUtils from '@src/styles/utils';
 import type {ThemeStylesActionsContextType, ThemeStylesStateContextType} from './types';
 
-const defaultThemeStylesStateContextValue: ThemeStylesStateContextType = {
-    styles: defaultStyles,
-};
+// Lazy defaults: defers the expensive styles(defaultTheme) call from module import
+// time to first access. In production, ThemeStylesProvider supplies real values so
+// these are never reached. Tests that render without the provider will trigger lazy
+// initialization on first access.
+let cachedState: ThemeStylesStateContextType | undefined;
+let cachedActions: ThemeStylesActionsContextType | undefined;
 
-const defaultThemeStylesActionsContextValue: ThemeStylesActionsContextType = {
-    StyleUtils: DefaultStyleUtils,
-};
+const defaultThemeStylesStateContextValue = new Proxy({} as ThemeStylesStateContextType, {
+    get(_, prop: keyof ThemeStylesStateContextType) {
+        if (!cachedState) {
+            cachedState = {styles: styles(defaultTheme)};
+        }
+        return cachedState[prop];
+    },
+});
+
+const defaultThemeStylesActionsContextValue = new Proxy({} as ThemeStylesActionsContextType, {
+    get(_, prop: keyof ThemeStylesActionsContextType) {
+        if (!cachedActions) {
+            if (!cachedState) {
+                cachedState = {styles: styles(defaultTheme)};
+            }
+            cachedActions = {StyleUtils: createStyleUtils(defaultTheme, cachedState.styles)};
+        }
+        return cachedActions[prop];
+    },
+});
 
 export {defaultThemeStylesStateContextValue, defaultThemeStylesActionsContextValue};

src/stories/CheckboxWithLabel.stories.tsx

@@ -3,8 +3,10 @@ import React from 'react';
 import CheckboxWithLabel from '@components/CheckboxWithLabel';
 import type {CheckboxWithLabelProps} from '@components/CheckboxWithLabel';
 import Text from '@components/Text';
-// eslint-disable-next-line no-restricted-imports
-import {defaultStyles} from '@styles/index';
+import styles from '@src/styles';
+import {defaultTheme} from '@src/styles/theme';
+
+const defaultStyles = styles(defaultTheme);
 
 type CheckboxWithLabelStory = StoryFn<typeof CheckboxWithLabel>;
 

src/stories/Composer.stories.tsx

@@ -9,11 +9,12 @@ import RenderHTML from '@components/RenderHTML';
 import Text from '@components/Text';
 import withNavigationFallback from '@components/withNavigationFallback';
 import useStyleUtils from '@hooks/useStyleUtils';
-// eslint-disable-next-line no-restricted-imports
-import {defaultTheme} from '@styles/theme';
-import {defaultStyles} from '@src/styles';
+import styles from '@src/styles';
+import {defaultTheme} from '@src/styles/theme';
 import type {FileObject} from '@src/types/utils/Attachment';
 
+const defaultStyles = styles(defaultTheme);
+
 const ComposerWithNavigation = withNavigationFallback(Composer);
 
 /**

src/stories/DragAndDrop.stories.tsx

@@ -4,7 +4,10 @@ import {Image, View} from 'react-native';
 import DragAndDropConsumer from '@components/DragAndDrop/Consumer';
 import DragAndDropProvider from '@components/DragAndDrop/Provider';
 import Text from '@components/Text';
-import {defaultStyles} from '@src/styles';
+import styles from '@src/styles';
+import {defaultTheme} from '@src/styles/theme';
+
+const defaultStyles = styles(defaultTheme);
 
 /**
  * We use the Component Story Format for writing stories. Follow the docs here:

src/stories/Form.stories.tsx

@@ -18,10 +18,13 @@ import {isRequiredFulfilled} from '@libs/ValidationUtils';
 import {clearErrors, setDraftValues, setErrors, setIsLoading} from '@userActions/FormActions';
 import CONST from '@src/CONST';
 import type {OnyxFormValuesMapping} from '@src/ONYXKEYS';
-import {defaultStyles} from '@src/styles';
+import styles from '@src/styles';
+import {defaultTheme} from '@src/styles/theme';
 import type {Form} from '@src/types/form';
 import type {Network} from '@src/types/onyx';
 
+const defaultStyles = styles(defaultTheme);
+
 type FormStory = StoryFn<FormProviderProps & FormProviderOnyxProps>;
 
 type StorybookFormValues = {

src/stories/NumberWithSymbolForm.stories.tsx

@@ -5,9 +5,11 @@ import NumberWithSymbolForm from '@components/NumberWithSymbolForm';
 import type {NumberWithSymbolFormProps} from '@components/NumberWithSymbolForm';
 import ScrollView from '@components/ScrollView';
 import withNavigationFallback from '@components/withNavigationFallback';
-// eslint-disable-next-line no-restricted-imports
-import {defaultStyles} from '@styles/index';
 import CONST from '@src/CONST';
+import styles from '@src/styles';
+import {defaultTheme} from '@src/styles/theme';
+
+const defaultStyles = styles(defaultTheme);
 
 type NumberWithSymbolFormStory = StoryFn<typeof NumberWithSymbolForm>;
 

src/styles/index.ts

@@ -19,7 +19,6 @@ import {getBrowser, isMobile, isMobileSafari, isSafari} from '@libs/Browser';
 import getPlatform from '@libs/getPlatform';
 import CONST from '@src/CONST';
 import type {Dimensions} from '@src/types/utils/Layout';
-import {defaultTheme} from './theme';
 import colors from './theme/colors';
 import type {ThemeColors} from './theme/types';
 import addOutlineWidth from './utils/addOutlineWidth';
@@ -6559,8 +6558,5 @@ const styles = (theme: ThemeColors) =>
 
 type ThemeStyles = ReturnType<typeof styles>;
 
-const defaultStyles = styles(defaultTheme);
-
 export default styles;
-export {defaultStyles};
 export type {ThemeStyles, StatusBarStyle, ColorScheme, AnchorPosition, AnchorDimensions, OverlayStylesParams};

src/styles/utils/index.ts

@@ -9,16 +9,13 @@ import {LETTER_AVATAR_COLOR_OPTIONS} from '@libs/Avatars/PresetAvatarCatalog';
 import {isMobile, isMobileChrome} from '@libs/Browser';
 import getPlatform from '@libs/getPlatform';
 import {hashText} from '@libs/UserUtils';
-// eslint-disable-next-line no-restricted-imports
-import {defaultTheme} from '@styles/theme';
 import colors from '@styles/theme/colors';
 import type {ThemeColors} from '@styles/theme/types';
 import variables from '@styles/variables';
 import CONST from '@src/CONST';
 import type {Transaction} from '@src/types/onyx';
 import type {Dimensions} from '@src/types/utils/Layout';
 import type Nullable from '@src/types/utils/Nullable';
-import {defaultStyles} from '..';
 import type {ThemeStyles} from '..';
 import shouldPreventScrollOnAutoCompleteSuggestion from './autoCompleteSuggestion';
 import getCardStyles from './cardStyles';
@@ -2291,8 +2288,5 @@ const createStyleUtils = (theme: ThemeColors, styles: ThemeStyles) => ({
 
 type StyleUtilsType = ReturnType<typeof createStyleUtils>;
 
-const DefaultStyleUtils = createStyleUtils(defaultTheme, defaultStyles);
-
 export default createStyleUtils;
-export {DefaultStyleUtils};
 export type {StyleUtilsType, AvatarSizeName};