Remove some O(n²) calls to reduce

[skonves]

No description provided.

[Copilot]

Pull request overview

This PR aims to improve performance by replacing O(n²) reduce operations with O(n) for-loops in mapper functions. The key change is replacing the pattern Object.keys(obj).reduce((acc, key) => { ..., return { ...acc, [key]: value } }, {}) with direct object mutation using for-loops, which avoids creating a new object on each iteration.

Key changes:

• Refactored pure map mapper functions to use for-loops instead of reduce with spread operators
• Relocated type union definitions to the end of files (after functions)
• Added TODO comments for remaining O(n²) code that wasn't refactored

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
packages/typescript-dtos/src/mapper-factory.ts	Updated code generator for pure map mappers; added TODOs for mixed mappers and compact function that weren't fully refactored
packages/typescript-dtos/src/snapshot/server/v1/types.ts	Moved union type declarations after function definitions
packages/typescript-dtos/src/snapshot/client/v1/types.ts	Moved union type declarations after function definitions
packages/http-client/src/snapshot/zod/v1/dtos/mappers.ts	Refactored pure map functions to use for-loops; mixed map functions still use reduce
packages/express/src/snapshot/zod/v1/types.ts	Removed deprecation comment from GetGizmosParams.search property
packages/express/src/snapshot/zod/v1/dtos/mappers.ts	Refactored pure map functions to use for-loops; mixed map functions still use reduce

Comments suppressed due to low confidence (2)

packages/typescript-dtos/src/mapper-factory.ts:251

• The TODO comment indicates this code should be refactored to use a for-loop (like the change in buildPureMapMapper at lines 354-359), but the refactoring was not completed. This leaves the O(n²) performance issue unfixed for mixed type mappers.

The refactoring should be:

const result: ${this.buildTypeNames(type.name.value, mode).output} = __defined__;
for (const key of Object.keys(__rest__)) {
  const value = ${this.builder.buildValue(mapProperties.value.value, mode, `${paramName}[key]`, asType)};
  if (value !== undefined) result[key] = value;
}
return result;

      // TODO: remove O(n²) call to reduce
      yield ``;
      yield `return Object.keys(__rest__).reduce((acc, key) => {`;
      yield `const value = ${this.builder.buildValue(mapProperties.value.value, mode, `${paramName}[key]`, asType)};`;
      yield `return value === undefined ? acc : { ...acc, [key]: value };`;
      yield `}, __defined__ as ${this.buildTypeNames(type.name.value, mode).output});`;

packages/typescript-dtos/src/mapper-factory.ts:733

• The TODO comment indicates this compact function should be refactored to remove the O(n²) call to reduce, but the refactoring was not completed. While this is a utility function that processes individual objects, the same performance improvement should be applied here for consistency.

The refactoring should be:

function compact<T extends object>(obj: T): T {
  const result = {} as T;
  for (const key of Object.keys(obj)) {
    const value = obj[key as keyof T];
    if (value !== undefined) {
      result[key as keyof T] = value;
    }
  }
  return result;
}

    // TODO: remove O(n²) call to reduce
    if (this._needsCompact) {
      yield `function compact<T extends object>(obj: T): T {
        return Object.keys(obj).reduce((acc, key) => {
          const value = obj[key as keyof T];
          if (value !== undefined) {
            acc[key as keyof T] = value;
          }
          return acc;
        }, {} as T);
      }`;
    }

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[Copilot]

The @deprecated JSDoc comment was removed from the search property. This appears to be an unintentional change that's unrelated to the PR's stated purpose of removing O(n²) calls. The deprecation status should be preserved unless there's a deliberate reason to remove it. Other deprecation comments remain in the codebase (e.g., line 202 for Gizmo type, line 207 for size property).

Suggested change

	export type GetGizmosParams = {
	export type GetGizmosParams = {
	/**
	* @deprecated
	*/

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.

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