perf: optimize blockList iteration with for...of instead of for...in#5304
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walterbender merged 4 commits intosugarlabs:masterfrom Feb 14, 2026
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Replace for...in loops with for...of for array iteration in blocks.js. This is a performance optimization because: - for...in iterates over enumerable properties including inherited ones - for...in is slower than for...of for arrays - for...of is the correct modern pattern for array iteration Optimized 23 functions including: - setBlockScale, bottomMostBlock, toggleCollapsibles - updateBlockPositions, bringToTop, checkBounds - moveAllBlocksExcept, _searchForArgFlow - changeDisabledStatus, unhighlightAll, hide, show - findUniqueActionName, findUniqueCustomName - findUniqueTemperamentName, _findDrumURLs - renameBoxes, renameStoreinBoxes, renameStorein2Boxes - renameNamedboxes All 2532 tests pass and browser testing confirms full functionality.
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✅ All Jest tests passed! This PR is ready to merge. |
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✅ All Jest tests passed! This PR is ready to merge. |
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✅ All Jest tests passed! This PR is ready to merge. |
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@walterbender resolved merged conflict |
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Summary
This PR optimizes array iteration in js/blocks.js by replacing
for...inloops withfor...ofloops.Problem
The codebase was using
for...into iterate overthis.blockList, which is an array. This is an anti-pattern because:for...initerates over all enumerable properties, including inherited onesfor...inis slower thanfor...offor arraysfor...ofis the correct modern JavaScript pattern for array iterationSolution
Replaced 23 instances of
for...inloops with proper array iteration:for...ofwhen only the element is neededfor...ofwith.entries()when both index and element are neededFunctions optimized:
setBlockScale(2 loops)findUniqueCustomName,findUniqueTemperamentNameTesting
Impact