refactor: refactor User.export to decrease complexity in src/user/settings.js

[qianxuege]

Refactor: src/user/settings.js

Overview

This refactor reduces cyclomatic complexity and improves maintainability of the user settings module without changing its external behavior or public API.

Goals

• Decrease complexity inside the exported initializer function.
• Separate concerns: validation, normalization, notification handling, persistence.
• Preserve existing behavior, data shape, and hook semantics.
• Prepare the module for easier future extension and unit testing.

Key Changes

Hoisted Constants

• spiderDefaultSettings
• remoteDefaultSettings

Extracted / Added Helper Functions

Helper	Responsibility
parseJSONSetting	Safe JSON parsing with fallback
getSetting	Unified resolution (user → remote default → global config → fallback)
enhanceNotificationSettings	Populate notification preference defaults
onSettingsLoaded	Normalize all settings after load (moved/hoisted)
validatePagination	Guard page size values
validateLanguages	Validate and default language fields
buildSettingsObject	Construct the persisted subset of settings
applyNotificationSettings	Merge user-provided notification overrides

User.saveSettings Simplification

Replaced inline logic with:

1. validatePagination (posts & topics)
2. validateLanguages
3. buildSettingsObject
4. applyNotificationSettings
5. Hook pipeline (action:user.saveSettings → filter:user.saveSettings)
6. Digest scheduling unchanged

Behavior Preserved

• Public API methods: getSettings, getMultipleUserSettings, saveSettings, updateDigestSetting, setSetting
• Storage key names and structure
• Default value resolution order:
  1. Explicit user value
  2. Remote default (for ActivityPub-style users)
  3. Global config (meta.config)
  4. Hardcoded fallback
• Notification type handling derived dynamically
• Digest frequency handling logic

Benefits

• Lower cognitive load when reading or modifying the module
• Clear single-purpose helpers encourage targeted unit tests
• Reduced risk of accidental side effects when adding new fields
• Easier future introduction of schema validation (e.g. Zod/Joi)

Non-Functional Notes

• No database migrations required
• No plugin or theme integration changes
• Hook contracts untouched

Suggested Follow-Ups (Optional)

1. Add unit tests for:
   • validatePagination
   • buildSettingsObject
   • getSetting (especially remote default precedence)
2. Cache notification type list if profiling shows repetition cost
3. Introduce schema-based validation layer
4. Further split onSettingsLoaded into:
   • Boolean coercions
   • Pagination normalization
   • Sorting & preference fields
5. Add TypeScript typings or JSDoc typedef for the settings object

Safety & Compatibility

• No breaking changes were introduced.
• Fallbacks and defaults match pre-refactor logic.
• Error messages for invalid pagination and language codes remain unchanged.

File Touched

• src/user/settings.js (structural refactor only; no semantic changes to outcomes)

Quick Reference: Data Flow After Refactor

Load flow:

1. Fetch raw object (or defaults for spider/remote)
2. onSettingsLoaded normalizes
3. Notification defaults via enhanceNotificationSettings
4. JSON lists parsed (chatAllowList, chatDenyList)

Save flow:

1. Validate pagination & languages
2. Fire action:user.saveSettings
3. Build canonical object
4. Merge notification overrides
5. Fire filter:user.saveSettings
6. Persist & update digest scheduling
7. Return fully normalized settings (getSettings re-run)

[Copilot]

Pull Request Overview

This PR refactors the User.export function in src/user/settings.js to reduce cyclomatic complexity by extracting helper functions and hoisting constants while preserving all existing behavior and public API contracts.

• Extracts inline logic into focused helper functions for validation, normalization, and notification handling
• Hoists constants and utility functions outside the main exported function to improve readability
• Simplifies the main saveSettings method by replacing complex inline validation with extracted helper calls

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[Copilot]

The remoteDefaultSettings variable is referenced but not defined in the visible code. This will cause a ReferenceError when this condition is evaluated.