Repository navigation
refactor(compat/lastIndexOf): use internal toArray helper for array like conversion - #1957
Merged
Merged
Conversation
|
The latest updates on your projects. Learn more about Vercel for GitHub.
|
Antoliny0919
force-pushed
the
optimistic-lio
branch
from
July 27, 2026 14:19
8fd6d51 to
5738d89
Compare
Collaborator
|
I got about 2x too on array input. One thing though — this changes what happens with sparse arrays (the ones with empty slots). lastIndexOf([1, , 1], undefined, 2)
// lodash: 1 main: 1 this PR: -1(I pass Maybe there's another way to make it faster — lodash never turns the input into an array at all, it just goes backwards by index, so empty slots never matter. Either way, a test for this case would help. |
raon0211
approved these changes
Jul 30, 2026
dayongkr
added a commit
to dayongkr/es-toolkit
that referenced
this pull request
Jul 30, 2026
toss#1957 swapped `Array.from(array)` for the `toArray` helper to skip a copy when the input is already an array. That works for dense arrays, but `toArray` returns an array unchanged, so the search now runs through `Array.prototype.lastIndexOf` on the original — and the native method skips holes, while `Array.from` had been filling them with `undefined`: ```js const sparse = [1]; sparse[2] = 1; lastIndexOf(sparse, undefined, 2); // lodash: 1 before toss#1957: 1 after toss#1957: -1 ``` lodash never converts the input at all; `baseLastIndexOf` walks backwards by index, so `array[i]` reads a hole as `undefined` and the question never comes up. Doing the same here fixes the behavior and keeps the copy elided for array-likes too, which is what toss#1957 was after. The `NaN` branch already looped this way; it just fell through to the native call when it found nothing, so it now returns -1 directly. Benchmarks: 1.15x faster than lodash on the existing performance suite, and the bundle size drops from 681 to 658 bytes since the `toArray` import goes away. Adds tests for holes — searching for `undefined`, for a value, and for `NaN` — plus array-like inputs, which had no coverage.
dayongkr
added a commit
to dayongkr/es-toolkit
that referenced
this pull request
Jul 30, 2026
toss#1957 swapped `Array.from(array)` for the `toArray` helper to skip a copy when the input is already an array. That works for dense arrays, but `toArray` returns an array unchanged, so the search now runs through `Array.prototype.lastIndexOf` on the original — and the native method skips holes, while `Array.from` had been filling them with `undefined`: ```js const sparse = [1]; sparse[2] = 1; lastIndexOf(sparse, undefined, 2); // lodash: 1 before toss#1957: 1 after toss#1957: -1 ``` lodash never converts the input at all; `baseLastIndexOf` walks backwards by index, so `array[i]` reads a hole as `undefined` and the question never comes up. Doing the same here fixes the behavior and keeps the copy elided for array-likes too, which is what toss#1957 was after. The `NaN` branch already looped this way; it just fell through to the native call when it found nothing, so it now returns -1 directly. Benchmarks: 1.15x faster than lodash on the existing performance suite, and the bundle size drops from 681 to 658 bytes since the `toArray` import goes away. Adds tests for holes — searching for `undefined`, for a value, and for `NaN` — plus array-like inputs, which had no coverage.
dayongkr
added a commit
that referenced
this pull request
Jul 30, 2026
…1977) #1957 swapped `Array.from(array)` for the `toArray` helper to skip a copy when the input is already an array. That works for dense arrays, but `toArray` returns an array unchanged, so the search now runs through `Array.prototype.lastIndexOf` on the original — and the native method skips holes, while `Array.from` had been filling them with `undefined`: ```js const sparse = [1]; sparse[2] = 1; lastIndexOf(sparse, undefined, 2); // lodash: 1 before #1957: 1 after #1957: -1 ``` lodash never converts the input at all; `baseLastIndexOf` walks backwards by index, so `array[i]` reads a hole as `undefined` and the question never comes up. Doing the same here fixes the behavior and keeps the copy elided for array-likes too, which is what #1957 was after. The `NaN` branch already looped this way; it just fell through to the native call when it found nothing, so it now returns -1 directly. Benchmarks: 1.15x faster than lodash on the existing performance suite, and the bundle size drops from 681 to 658 bytes since the `toArray` import goes away. Adds tests for holes — searching for `undefined`, for a value, and for `NaN` — plus array-like inputs, which had no coverage.
1 task
gwennlbh
pushed a commit
to cigaleapp/cigale
that referenced
this pull request
Sep 8, 2026
##### [v1.52.0](https://github.com/toss/es-toolkit/blob/HEAD/CHANGELOG.md#Version-v1520) Released on August 28th, 2026. - Added the `es-toolkit/iterator` entrypoint, a lazy iterator module with `chunk`, `count`, `dropWhile`, `head`, `iterate`, `partition`, `range`, `scan`, `takeWhile`, `uniqBy`, and `zip` (\[[#1815](toss/es-toolkit#1815)]), plus `cartesianProduct` (\[[#2031](toss/es-toolkit#2031)]). The same functions are also available from `es-toolkit/fp/iterator`. - Added `defer` and `deferAsync` to `es-toolkit/util`. (\[[#2032](toss/es-toolkit#2032)]) - Added `flowAsync` to `es-toolkit/fp`, a promise-aware left-to-right composition. (\[[#2033](toss/es-toolkit#2033)]) - Added the `EmptyObject`, `IsEqual`, `JSONValue`, `Primitive`, `SetOptional`, `SetRequired`, and `UnknownRecord` types. (\[[#2044](toss/es-toolkit#2044)]) - Fixed `merge` to infer the deep merged return type, and exported the `Merge` type. (\[[#1959](toss/es-toolkit#1959)]) - Fixed `omitBy` and `pickBy` to type numeric callback keys as strings, and exported the `ObjectKeys` type. (\[[#2037](toss/es-toolkit#2037)]) - Fixed `attempt` and `attemptAsync` to default their error type parameter to `unknown`. (\[[#2052](toss/es-toolkit#2052)]) The following bring `es-toolkit/compat` closer to Lodash. Behavior for the affected edge cases now matches Lodash, so results may differ if you relied on the previous output. - Fixed `compat/debounce` to skip the `maxWait` invocation when both `leading` and `trailing` are `false`. (\[[#1678](toss/es-toolkit#1678)]) - Fixed `compat/toString` to convert objects with a custom `valueOf`. (\[[#2034](toss/es-toolkit#2034)]) - Fixed `compat/mergeWith` to assign `null` values in array sources. (\[[#1929](toss/es-toolkit#1929)]) - Fixed `compat/has` and `compat/hasIn` to normalize the `-0` path key. (\[[#2035](toss/es-toolkit#2035)]) - Fixed `compat/differenceWith` and `compat/without` to normalize `-0` to `0`. (\[[#2049](toss/es-toolkit#2049)]) - Fixed `compat/findLastIndex` to convert `fromIndex` to an integer. (\[[#2047](toss/es-toolkit#2047)]) - Fixed `compat/xorWith` to match Lodash when no comparator is given. (\[[#2057](toss/es-toolkit#2057)]) - Covered the new iterator entrypoints in the dist and browser compatibility checks. (\[[#2030](toss/es-toolkit#2030)]) - Made the agent skills portable when installed on their own. (\[[#2054](toss/es-toolkit#2054)]) - Fixed documentation typos and the Deno install commands. (\[[#2062](toss/es-toolkit#2062)]) ##### [v1.51.0](https://github.com/toss/es-toolkit/blob/HEAD/CHANGELOG.md#Version-v1510) Released on August 17th, 2026. - Added the `es-toolkit/bigint` entrypoint: `bigint` counterparts of the math functions (`sum`, `sumBy`, `max`, `min`, `maxBy`, `minBy`, `clamp`, `inRange`, `median`, `medianBy`, `percentile`, `range`, `rangeRight`), kept separate so the `number` implementations stay unchanged. (\[[#1966](toss/es-toolkit#1966)]) - Added `dedent`, which removes common leading whitespace from template strings. (\[[#1679](toss/es-toolkit#1679)]) - Added `deepFreeze` for recursively freezing objects. (\[[#1680](toss/es-toolkit#1680)]) - Added `mapValuesAsync` and `mapKeysAsync`. (\[[#1544](toss/es-toolkit#1544)]) - Added `toPascalCaseKeys`, `toKebabCaseKeys`, and `toConstantCaseKeys`, completing the object key casing family. (\[[#1984](toss/es-toolkit#1984)]) - Exported the `ToCamelCaseKeys`, `ToPascalCaseKeys`, `ToSnakeCaseKeys`, `ToKebabCaseKeys`, and `ToConstantCaseKeys` types. (\[[#1651](toss/es-toolkit#1651)]) - Added a `preserveArrays` option to `flattenObject`. (\[[#974](toss/es-toolkit#974)]) - Fixed `retry` to pass the last error to the `delay` callback (\[[#1759](toss/es-toolkit#1759)]) and to throw the last attempt's error without applying a final delay (\[[#1901](toss/es-toolkit#1901)]). - Fixed `mergeWith` and `toMerged` to handle mixed array/object types consistently with `merge`. (\[[#2026](toss/es-toolkit#2026)]) - Fixed `pullAt` to remove the correct elements with negative indices. (\[[#1613](toss/es-toolkit#1613)]) - Fixed `at`, `pullAt`, `orderBy`, and `sortBy` to accept readonly arrays. (\[[#2016](toss/es-toolkit#2016)]) - Moved `limitAsync` from the array to the promise category. (\[[#2022](toss/es-toolkit#2022)]) - Included the NOTICE file in the published npm and JSR packages. (\[[#2020](toss/es-toolkit#2020)]) The following bring `es-toolkit/compat` closer to Lodash. Behavior for the affected edge cases now matches Lodash, so results may differ if you relied on the previous output. - Added `entries` and `entriesIn`. (\[[#1874](toss/es-toolkit#1874)]) - Fixed `compat/isMatch` and `compat/isMatchWith` to handle object source patterns against primitive and non-plain-object targets like Lodash. (\[[#1432](toss/es-toolkit#1432)]) - Fixed `compat/set` to block `constructor.prototype` paths, preventing prototype pollution. (\[[#1904](toss/es-toolkit#1904)]) - Fixed `compat/find` to respect array-like `length` (\[[#1958](toss/es-toolkit#1958)]) and to convert `fromIndex` to an integer (\[[#1961](toss/es-toolkit#1961)]), and `compat/indexOf` to convert `fromIndex` to an integer when searching for `NaN` (\[[#1951](toss/es-toolkit#1951)]). - Fixed `compat/orderBy` to resolve unresolved deep paths and nullish elements to `undefined` (\[[#2010](toss/es-toolkit#2010)]), to exclude the `length` property from array-like values (\[[#2002](toss/es-toolkit#2002)]), and to read the criterion property from primitive values (\[[#1903](toss/es-toolkit#1903)]). - Fixed `compat/toPath` to split unquoted dotted keys inside brackets. (\[[#1899](toss/es-toolkit#1899)]) - Fixed `compat/omit` to treat a key array as a single deep path. (\[[#1902](toss/es-toolkit#1902)]) - Fixed `compat/map` to make the iteratee optional with an identity default. (\[[#1928](toss/es-toolkit#1928)]) - Fixed `compat/size` to count combined Unicode symbols as single characters. (\[[#1900](toss/es-toolkit#1900)]) - Fixed `compat/intersectionBy` to support number, object, and nullish iteratee shorthands (\[[#1993](toss/es-toolkit#1993)]), and `compat/intersectionWith` to apply the comparator when deduplicating the first array (\[[#1953](toss/es-toolkit#1953)]). - Fixed `compat/difference`, `compat/differenceBy`, `compat/uniqBy`, and `compat/unionBy` to normalize `-0` to `0`. (\[[#2007](toss/es-toolkit#2007)]) - Fixed `compat/maxBy` and `compat/minBy` to skip nullish iteratee values (\[[#1927](toss/es-toolkit#1927)]), and `compat/meanBy` to skip `undefined` values when averaging (\[[#1978](toss/es-toolkit#1978)]). - Fixed `compat/some`, `compat/template` (\[[#2009](toss/es-toolkit#2009)]), and `compat/fill` (\[[#1952](toss/es-toolkit#1952)]) to gate guard handling with `isIterateeCall`. - Fixed `compat/iteratee` to treat a boolean as a property shorthand. (\[[#1941](toss/es-toolkit#1941)]) - Fixed `compat/reverse` to support array-like objects and `arguments`. (\[[#2008](toss/es-toolkit#2008)]) - Fixed `compat/toArray` to convert non-array-like iterables. (\[[#1999](toss/es-toolkit#1999)]) - Fixed `compat/toString` to render nested nullish values like Lodash. (\[[#1992](toss/es-toolkit#1992)]) - Fixed `compat/zipObject` to treat `null` keys and values as empty arrays. (\[[#2005](toss/es-toolkit#2005)]) - Fixed `compat/sampleSize` to clamp the default size to the collection length. (\[[#2003](toss/es-toolkit#2003)]) - Fixed `compat/takeWhile`, `compat/takeRightWhile`, and `compat/uniqBy` to support string inputs. (\[[#2004](toss/es-toolkit#2004)]) - Fixed `compat/chunk` to return an empty array for an empty collection with an `Infinity` size. (\[[#1995](toss/es-toolkit#1995)]) - Fixed `compat/lastIndexOf` to read holes in sparse arrays as `undefined`. (\[[#1977](toss/es-toolkit#1977)]) - Fixed `compat/last` to return `undefined` for empty array-like inputs. (\[[#1954](toss/es-toolkit#1954)]) - Fixed `compat/pullAll` to return the array as-is when `values` is nullish. (\[[#1962](toss/es-toolkit#1962)]) - Added a browser compatibility test suite. (\[[#2012](toss/es-toolkit#2012)]) - Improved documentation, JSDoc accuracy, tests, and internal refactoring across `compat` and the docs site. (\[[#1622](toss/es-toolkit#1622)], \[[#1789](toss/es-toolkit#1789)], \[[#1824](toss/es-toolkit#1824)], \[[#1844](toss/es-toolkit#1844)], \[[#1849](toss/es-toolkit#1849)], \[[#1854](toss/es-toolkit#1854)], \[[#1855](toss/es-toolkit#1855)], \[[#1859](toss/es-toolkit#1859)], \[[#1860](toss/es-toolkit#1860)], \[[#1868](toss/es-toolkit#1868)], \[[#1871](toss/es-toolkit#1871)], \[[#1887](toss/es-toolkit#1887)], \[[#1898](toss/es-toolkit#1898)], \[[#1933](toss/es-toolkit#1933)], \[[#1939](toss/es-toolkit#1939)], \[[#1947](toss/es-toolkit#1947)], \[[#1950](toss/es-toolkit#1950)], \[[#1955](toss/es-toolkit#1955)], \[[#1956](toss/es-toolkit#1956)], \[[#1957](toss/es-toolkit#1957)], \[[#1960](toss/es-toolkit#1960)], \[[#1963](toss/es-toolkit#1963)], \[[#1964](toss/es-toolkit#1964)], \[[#1968](toss/es-toolkit#1968)], \[[#1969](toss/es-toolkit#1969)], \[[#1970](toss/es-toolkit#1970)], \[[#1972](toss/es-toolkit#1972)], \[[#1979](toss/es-toolkit#1979)], \[[#1985](toss/es-toolkit#1985)], \[[#2000](toss/es-toolkit#2000)], \[[#2001](toss/es-toolkit#2001)], \[[#2021](toss/es-toolkit#2021)], \[[#2025](toss/es-toolkit#2025)], \[[#2027](toss/es-toolkit#2027)]) We sincerely thank [@Antoliny0919](https://github.com/Antoliny0919), [@D-Sketon](https://github.com/D-Sketon), [@kojesung](https://github.com/kojesung), [@chuenchen309](https://github.com/chuenchen309), [@mariazuheros](https://github.com/mariazuheros), [@DongEun02](https://github.com/DongEun02), [@raon0211](https://github.com/raon0211), [@sukvvon](https://github.com/sukvvon), [@racgoo](https://github.com/racgoo), [@dayongkr](https://github.com/dayongkr), [@Kropiunig](https://github.com/Kropiunig), [@ssi02014](https://github.com/ssi02014), [@sarathfrancis90](https://github.com/sarathfrancis90), [@mym0404](https://github.com/mym0404), [@mlnwns](https://github.com/mlnwns), [@kdelay](https://github.com/kdelay), [@gwagjiug](https://github.com/gwagjiug), [@dohwi](https://github.com/dohwi), [@blro0319](https://github.com/blro0319), [@benedictleejh](https://github.com/benedictleejh), [@amir-rezaei](https://github.com/amir-rezaei), [@ianzone](https://github.com/ianzone), [@sen2y](https://github.com/sen2y), [@rossyman](https://github.com/rossyman), [@eunwoo-levi](https://github.com/eunwoo-levi), [@ramong26](https://github.com/ramong26), [@Gdm0714](https://github.com/Gdm0714), and everyone else who contributed. We appreciate your great efforts! Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
This branch was successfully deployed
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Use toArray to avoid unnecessary conversions for arrays.
Bench
Before
After