[sarathfrancis90]

Summary

I was diffing es-toolkit/compat against lodash 4.17.21 and hit this on sortBy:

sortBy(['b', 'aa'], 'length');   // compat: ['aa', 'b']   lodash: ['b', 'aa']
orderBy(['ba', 'ab', 'b'], 0);   // compat: ['ab', 'b', 'ba']   lodash: ['ab', 'ba', 'b']

getValueByCriterion only looked the criterion up when the element was an object, and returned the element itself otherwise, so the criterion was silently dropped for strings and numbers and the collection got sorted by its own values. map(['b', 'aa'], 'length') already returns [1, 2], so compat was inconsistent with itself here too.

Reading the property directly is enough — primitives box on property access, so 'aa'.length is 2 and (3).b is undefined, which is what lodash's property iteratee produces. When no element has the key every criterion is undefined and the input order is kept, same as lodash.

This is compat-only; es-toolkit/orderBy is untouched, so #1096 / #1552 (primitive support in the main library) stay closed as they were.

Changes

• src/compat/array/orderBy.ts: drop the typeof object === 'object' guard around the criterion lookup.

• Tests for the property read and for the "no element has the key" case, in both specs.

• Updated the existing _.map iteratee expectation in orderBy.spec.ts. map passes the index as the criterion, and numbers have no such property, so lodash returns the collections unsorted:

  [[2, 1, 3], [3, 2, 1]].map(_.orderBy)   // [[2, 1, 3], [3, 2, 1]]
  [[2, 1, 3], [3, 2, 1]].map(_.sortBy)    // [[1, 2, 3], [1, 2, 3]]

  sortBy differs because it clears the criteria via isIterateeCall; orderBy has no such guard. The old expectation only passed because the criterion was being ignored.

Test results

Test Files  641 passed (641)
     Tests  4436 passed | 2 skipped (4438)

tsc --noEmit, yarn lint and prettier -c on the changed files are clean, and re-running the differential fuzz over sortBy/orderBy (80k random inputs) now shows no value differences against lodash.

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Project	Deployment	Actions	Updated (UTC)
es-toolkit	Ready	Preview, Comment	Jul 19, 2026 8:15am

[raon0211]

Thanks!