All notable changes to this project will be documented in this file. See [standard-version](https://github.com/conventional-changelog/standard-version) for commit guidelines.
* **locale:** Turkish camelize and decamelize issues with toLocaleLowerCase/toLocaleUpperCase ([2617303](https://www.github.com/yargs/yargs-parser/commit/261730383e02448562f737b94bbd1f164aed5143))
* **perf:** address slow parse when using unknown-options-as-args ([#394](https://www.github.com/yargs/yargs-parser/issues/394)) ([441f059](https://www.github.com/yargs/yargs-parser/commit/441f059d585d446551068ad213db79ac91daf83a))
* **string-utils:** detect [0,1] ranged values as numbers ([#388](https://www.github.com/yargs/yargs-parser/issues/388)) ([efcc32c](https://www.github.com/yargs/yargs-parser/commit/efcc32c2d6b09aba31abfa2db9bd947befe5586b))
* **populate--:** -- should always be array ([#354](https://www.github.com/yargs/yargs-parser/issues/354)) ([585ae8f](https://www.github.com/yargs/yargs-parser/commit/585ae8ffad74cc02974f92d788e750137fd65146))
* do not lowercase camel cased string ([#348](https://www.github.com/yargs/yargs-parser/issues/348)) ([5f4da1f](https://www.github.com/yargs/yargs-parser/commit/5f4da1f17d9d50542d2aaa206c9806ce3e320335))
* **exports:** node 13.0 and 13.1 require the dotted object form _with_ a string fallback ([#336](https://www.github.com/yargs/yargs-parser/issues/336)) ([3ae7242](https://www.github.com/yargs/yargs-parser/commit/3ae7242040ff876d28dabded60ac226e00150c88))
* **unknown-options-as-args:** convert positionals that look like numbers ([#326](https://www.github.com/yargs/yargs-parser/issues/326)) ([f85ebb4](https://www.github.com/yargs/yargs-parser/commit/f85ebb4face9d4b0f56147659404cbe0002f3dad))
* only strip camel case if hyphenated ([#316](https://www.github.com/yargs/yargs-parser/issues/316)) ([95a9e78](https://www.github.com/yargs/yargs-parser/commit/95a9e785127b9bbf2d1db1f1f808ca1fb100e82a)), closes [#315](https://www.github.com/yargs/yargs-parser/issues/315)
### Code Refactoring
* do not ship type definitions ([#318](https://www.github.com/yargs/yargs-parser/issues/318)) ([8fbd56f](https://www.github.com/yargs/yargs-parser/commit/8fbd56f1d0b6c44c30fca62708812151ca0ce330))
* **build:** switch to action for publish ([#308](https://www.github.com/yargs/yargs-parser/issues/308)) ([5c2f305](https://www.github.com/yargs/yargs-parser/commit/5c2f30585342bcd8aaf926407c863099d256d174))
* **types:** envPrefix should be optional ([#305](https://www.github.com/yargs/yargs-parser/issues/305)) ([ae3f180](https://www.github.com/yargs/yargs-parser/commit/ae3f180e14df2de2fd962145f4518f9aa0e76523))
* **ts:** projects using `@types/yargs-parser` may see variations in type definitions.
* drops Node 6. begin following Node.js LTS schedule (#278)
### Features
* adds support for ESM and Deno ([#295](https://www.github.com/yargs/yargs-parser/issues/295)) ([195bc4a](https://www.github.com/yargs/yargs-parser/commit/195bc4a7f20c2a8f8e33fbb6ba96ef6e9a0120a1))
* expose camelCase and decamelize helpers ([#296](https://www.github.com/yargs/yargs-parser/issues/296)) ([39154ce](https://www.github.com/yargs/yargs-parser/commit/39154ceb5bdcf76b5f59a9219b34cedb79b67f26))
* **deps:** update to latest camelcase/decamelize ([#281](https://www.github.com/yargs/yargs-parser/issues/281)) ([8931ab0](https://www.github.com/yargs/yargs-parser/commit/8931ab08f686cc55286f33a95a83537da2be5516))
### Bug Fixes
* boolean numeric short option ([#294](https://www.github.com/yargs/yargs-parser/issues/294)) ([f600082](https://www.github.com/yargs/yargs-parser/commit/f600082c959e092076caf420bbbc9d7a231e2418))
* raise permission error for Deno if config load fails ([#298](https://www.github.com/yargs/yargs-parser/issues/298)) ([1174e2b](https://www.github.com/yargs/yargs-parser/commit/1174e2b3f0c845a1cd64e14ffc3703e730567a84))
* **deps:** update dependency decamelize to v3 ([#274](https://www.github.com/yargs/yargs-parser/issues/274)) ([4d98698](https://www.github.com/yargs/yargs-parser/commit/4d98698bc6767e84ec54a0842908191739be73b7))
* **types:** switch back to using Partial types ([#293](https://www.github.com/yargs/yargs-parser/issues/293)) ([bdc80ba](https://www.github.com/yargs/yargs-parser/commit/bdc80ba59fa13bc3025ce0a85e8bad9f9da24ea7))
### Build System
* drops Node 6. begin following Node.js LTS schedule ([#278](https://www.github.com/yargs/yargs-parser/issues/278)) ([9014ed7](https://www.github.com/yargs/yargs-parser/commit/9014ed722a32768b96b829e65a31705db5c1458a))
### Code Refactoring
* **ts:** move index.js to TypeScript ([#292](https://www.github.com/yargs/yargs-parser/issues/292)) ([f78d2b9](https://www.github.com/yargs/yargs-parser/commit/f78d2b97567ac4828624406e420b4047c710b789))
* **array, nargs:** support -o=--value and --option=--value format ([#262](https://www.github.com/yargs/yargs-parser/issues/262)) ([41d3f81](https://www.github.com/yargs/yargs-parser/commit/41d3f8139e116706b28de9b0de3433feb08d2f13))
* \_\_proto\_\_ will now be replaced with \_\_\_proto\_\_\_ in parse ([#258](https://www.github.com/yargs/yargs-parser/issues/258)), patching a potential
prototype pollution vulnerability. This was reported by the Snyk Security Research Team.([63810ca](https://www.github.com/yargs/yargs-parser/commit/63810ca1ae1a24b08293a4d971e70e058c7a41e2))
* the narg count is now enforced when parsing arrays.
### Features
* NaN can now be provided as a value for nargs, indicating "at least" one value is expected for array ([#251](https://www.github.com/yargs/yargs-parser/issues/251)) ([9db4be8](https://www.github.com/yargs/yargs-parser/commit/9db4be81417a2c7097128db34d86fe70ef4af70c))
* normalized keys were not enumerable ([#247](https://www.github.com/yargs/yargs-parser/issues/247)) ([57119f9](https://www.github.com/yargs/yargs-parser/commit/57119f9f17cf27499bd95e61c2f72d18314f11ba))
* this reverts parsing behavior of booleans to that of yargs@14
* objects used during parsing are now created with a null
prototype. There may be some scenarios where this change in behavior
leaks externally.
### Features
* boolean arguments will not be collected into an implicit array ([#236](https://www.github.com/yargs/yargs-parser/issues/236)) ([34c4e19](https://www.github.com/yargs/yargs-parser/commit/34c4e19bae4e7af63e3cb6fa654a97ed476e5eb5))
* address bugs with "uknown-options-as-args" ([bc023e3](https://www.github.com/yargs/yargs-parser/commit/bc023e3b13e20a118353f9507d1c999bf388a346))
* array should take precedence over nargs, but enforce nargs ([#243](https://www.github.com/yargs/yargs-parser/issues/243)) ([4cbc188](https://www.github.com/yargs/yargs-parser/commit/4cbc188b7abb2249529a19c090338debdad2fe6c))
* support keys that collide with object prototypes ([#234](https://www.github.com/yargs/yargs-parser/issues/234)) ([1587b6d](https://www.github.com/yargs/yargs-parser/commit/1587b6d91db853a9109f1be6b209077993fee4de))
* unknown options terminated with digits now handled by unknown-options-as-args ([#238](https://www.github.com/yargs/yargs-parser/issues/238)) ([d36cdfa](https://www.github.com/yargs/yargs-parser/commit/d36cdfa854254d7c7e0fe1d583818332ac46c2a5))
* populate error if incompatible narg/count or array/count options are used (#191)
### Features
* options that have had their default value used are now tracked ([#211](https://www.github.com/yargs/yargs-parser/issues/211)) ([a525234](https://www.github.com/yargs/yargs-parser/commit/a525234558c847deedd73f8792e0a3b77b26e2c0))
* populate error if incompatible narg/count or array/count options are used ([#191](https://www.github.com/yargs/yargs-parser/issues/191)) ([84a401f](https://www.github.com/yargs/yargs-parser/commit/84a401f0fa3095e0a19661670d1570d0c3b9d3c9))
