perf: optimize Object.keys() checks and optional chaining #15865
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Pull request overview
This PR implements several performance optimizations across the Mongoose codebase:
- Introduces a new
utils.hasOwnKeys()helper that checks for object keys more efficiently thanObject.keys().length - Converts verbose property access chains to optional chaining syntax
- Caches repeated property lookups to avoid redundant access
- Optimizes
indexOf()calls by caching results - Converts
argumentsobject usage to rest parameters - Optimizes Set operations for duplicate checking
Reviewed changes
Copilot reviewed 35 out of 35 changed files in this pull request and generated no comments.
Show a summary per file
| File | Description |
|---|---|
| lib/utils.js | Adds hasOwnKeys() helper function and updates isEmptyObject() to use it |
| lib/types/subdocument.js | Replaces Object.keys(ret).length === 0 with hasOwnKeys() |
| lib/types/documentArray/methods/index.js | Converts property access chains to optional chaining |
| lib/types/documentArray/index.js | Converts property access chains to optional chaining |
| lib/types/array/methods/index.js | Replaces Object.keys() length checks with hasOwnKeys() |
| lib/types/array/index.js | Converts property access chains to optional chaining |
| lib/schemaType.js | Simplifies null/undefined check to != null |
| lib/schema/subdocument.js | Converts to optional chaining and uses hasOwnKeys() |
| lib/schema/string.js | Simplifies null/undefined checks to != null |
| lib/schema/number.js | Simplifies null/undefined checks to != null |
| lib/schema/mixed.js | Replaces Object.keys() check with hasOwnKeys() |
| lib/schema/map.js | Replaces Object.keys() check with hasOwnKeys() |
| lib/schema/array.js | Converts property access chain to optional chaining |
| lib/schema.js | Converts to optional chaining and uses hasOwnKeys() |
| lib/queryHelpers.js | Converts to optional chaining |
| lib/query.js | Caches repeated property access, converts to rest parameters, uses hasOwnKeys(), and optional chaining |
| lib/plugins/trackTransaction.js | Replaces Object.keys() checks with hasOwnKeys() |
| lib/mongoose.js | Converts to optional chaining and uses hasOwnKeys() |
| lib/model.js | Converts to optional chaining and uses hasOwnKeys() |
| lib/helpers/update/castArrayFilters.js | Adds utils import and uses hasOwnKeys() |
| lib/helpers/update/applyTimestampsToUpdate.js | Adds utils import and uses hasOwnKeys() |
| lib/helpers/schema/getIndexes.js | Simplifies null/undefined check to != null |
| lib/helpers/schema/applyWriteConcern.js | Adds utils import, uses optional chaining and hasOwnKeys() |
| lib/helpers/schema/applyReadConcern.js | Converts to optional chaining |
| lib/helpers/query/castUpdate.js | Uses hasOwnKeys() for empty object checks |
| lib/helpers/populate/getModelsMapForPopulate.js | Optimizes duplicate checking with Set, uses optional chaining and hasOwnKeys() |
| lib/helpers/document/compile.js | Converts to optional chaining and uses hasOwnKeys() |
| lib/helpers/document/applyVirtuals.js | Adds utils import and uses hasOwnKeys() |
| lib/helpers/document/applyTimestamps.js | Adds utils import and uses hasOwnKeys() |
| lib/drivers/node-mongodb-native/connection.js | Converts to optional chaining and uses hasOwnKeys() |
| lib/drivers/node-mongodb-native/collection.js | Converts to optional chaining |
| lib/document.js | Optimizes with Set for key deduplication, caches schema options, uses hasOwnKeys() |
| lib/cursor/changeStream.js | Converts to optional chaining |
| lib/connection.js | Caches indexOf() results and uses hasOwnKeys() |
| lib/cast.js | Converts to optional chaining and uses hasOwnKeys() |
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hasezoey
approved these changes
Dec 4, 2025
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Pull request overview
Copilot reviewed 35 out of 35 changed files in this pull request and generated no new comments.
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Summary
utils.hasOwnKeys()helper that checks for empty objects without allocating an array viaObject.keys()Object.keys(obj).lengthpattern withhasOwnKeys(), reading the first key only instead of creating an array for all keys.a && a.b && a.b.cto optional chaininga?.b?.cthis.$__schema.options,model.db.options)indexOf()calls by caching the result instead of calling twiceargumentsto rest parameters inQuery.prototype.slice()Setoperations indocument.overwrite()andgetModelsMapForPopulate()