# [4.2.2](https://github.com/TehShrike/deepmerge/releases/tag/v4.2.2) - `isMergeableObject` is now only called if there are two values that could be merged. [a34dd4d2](https://github.com/TehShrike/deepmerge/commit/a34dd4d25bf5e250653540a2022bc832c7b00a19) # [4.2.1](https://github.com/TehShrike/deepmerge/releases/tag/v4.2.1) - Fix: falsey values can now be merged. [#170](https://github.com/TehShrike/deepmerge/issues/170) # [4.2.0](https://github.com/TehShrike/deepmerge/releases/tag/v4.2.0) - Properties are now only overwritten if they exist on the target object and are enumerable. [#164](https://github.com/TehShrike/deepmerge/pull/164) Technically this could probably be a patch release since "which properties get overwritten" wasn't documented and accidentally overwriting a built-in function or some function up the property chain would almost certainly be undesirable, but it feels like a gray area, so here we are with a feature version bump. # [4.1.2](https://github.com/TehShrike/deepmerge/releases/tag/v4.1.2) - Rolled back #167 since `Object.assign` breaks ES5 support. [55067352](https://github.com/TehShrike/deepmerge/commit/55067352a92c65a6c44a5165f3387720aae1e192) # [4.1.1](https://github.com/TehShrike/deepmerge/releases/tag/v4.1.1) - The `options` argument is no longer mutated [#167](https://github.com/TehShrike/deepmerge/pull/167) # [4.1.0](https://github.com/TehShrike/deepmerge/releases/tag/v4.1.0) - `cloneUnlessOtherwiseSpecified` is now exposed to the `arrayMerge` function [#165](https://github.com/TehShrike/deepmerge/pull/165) # [4.0.0](https://github.com/TehShrike/deepmerge/releases/tag/v4.0.0) - The `main` entry point in `package.json` is now a CommonJS module instead of a UMD module [#155](https://github.com/TehShrike/deepmerge/pull/155) # [3.3.0](https://github.com/TehShrike/deepmerge/releases/tag/v3.3.0) - Enumerable Symbol properties are now copied [#151](https://github.com/TehShrike/deepmerge/pull/151) # [3.2.1](https://github.com/TehShrike/deepmerge/releases/tag/v3.2.1) - bumping dev dependency versions to try to shut up bogus security warnings from Github/npm [#149](https://github.com/TehShrike/deepmerge/pull/149) # [3.2.0](https://github.com/TehShrike/deepmerge/releases/tag/v3.2.0) - feature: added the [`customMerge`](https://github.com/TehShrike/deepmerge#custommerge) option [#133](https://github.com/TehShrike/deepmerge/pull/133) # [3.1.0](https://github.com/TehShrike/deepmerge/releases/tag/v3.1.0) - typescript typing: make the `all` function generic [#129](https://github.com/TehShrike/deepmerge/pull/129) # [3.0.0](https://github.com/TehShrike/deepmerge/releases/tag/v3.0.0) - drop ES module build [#123](https://github.com/TehShrike/deepmerge/issues/123) # [2.2.1](https://github.com/TehShrike/deepmerge/releases/tag/v2.2.1) - bug: typescript export type was wrong [#121](https://github.com/TehShrike/deepmerge/pull/121) # [2.2.0](https://github.com/TehShrike/deepmerge/releases/tag/v2.2.0) - feature: added TypeScript typings [#119](https://github.com/TehShrike/deepmerge/pull/119) # [2.1.1](https://github.com/TehShrike/deepmerge/releases/tag/v2.1.1) - documentation: Rename "methods" to "api", note ESM syntax [#103](https://github.com/TehShrike/deepmerge/pull/103) - documentation: Fix grammar [#107](https://github.com/TehShrike/deepmerge/pull/107) - documentation: Restructure headers for clarity + some wording tweaks [108](https://github.com/TehShrike/deepmerge/pull/108) + [109](https://github.com/TehShrike/deepmerge/pull/109) # [2.1.0](https://github.com/TehShrike/deepmerge/releases/tag/v2.1.0) - feature: Support a custom `isMergeableObject` function [#96](https://github.com/TehShrike/deepmerge/pull/96) - documentation: note a Webpack bug that some users might need to work around [#100](https://github.com/TehShrike/deepmerge/pull/100) # [2.0.1](https://github.com/TehShrike/deepmerge/releases/tag/v2.0.1) - documentation: fix the old array merge algorithm in the readme. [#84](https://github.com/TehShrike/deepmerge/pull/84) # [2.0.0](https://github.com/TehShrike/deepmerge/releases/tag/v2.0.0) - breaking: the array merge algorithm has changed from a complicated thing to `target.concat(source).map(element => cloneUnlessOtherwiseSpecified(element, optionsArgument))` - breaking: The `clone` option now defaults to `true` - feature: `merge.all` now accepts an array of any size, even 0 or 1 elements See [pull request 77](https://github.com/TehShrike/deepmerge/pull/77). # [1.5.2](https://github.com/TehShrike/deepmerge/releases/tag/v1.5.2) - fix: no longer attempts to merge React elements [#76](https://github.com/TehShrike/deepmerge/issues/76) # [1.5.1](https://github.com/TehShrike/deepmerge/releases/tag/v1.5.1) - bower support: officially dropping bower support. If you use bower, please depend on the [unpkg distribution](https://unpkg.com/deepmerge/dist/umd.js). See [#63](https://github.com/TehShrike/deepmerge/issues/63) # [1.5.0](https://github.com/TehShrike/deepmerge/releases/tag/v1.5.0) - bug fix: merging objects into arrays was allowed, and doesn't make any sense. [#65](https://github.com/TehShrike/deepmerge/issues/65) published as a feature release instead of a patch because it is a decent behavior change. # [1.4.4](https://github.com/TehShrike/deepmerge/releases/tag/v1.4.4) - bower support: updated `main` in bower.json # [1.4.3](https://github.com/TehShrike/deepmerge/releases/tag/v1.4.3) - bower support: inline is-mergeable-object in a new CommonJS build, so that people using both bower and CommonJS can bundle the library [0b34e6](https://github.com/TehShrike/deepmerge/commit/0b34e6e95f989f2fc8091d25f0d291c08f3d2d24) # [1.4.2](https://github.com/TehShrike/deepmerge/releases/tag/v1.4.2) - performance: bump is-mergeable-object dependency version for a slight performance improvement [5906c7](https://github.com/TehShrike/deepmerge/commit/5906c765d691d48e83d76efbb0d4b9ca150dc12c) # [1.4.1](https://github.com/TehShrike/deepmerge/releases/tag/v1.4.1) - documentation: fix unpkg link [acc45b](https://github.com/TehShrike/deepmerge/commit/acc45be85519c1df906a72ecb24764b622d18d47) # [1.4.0](https://github.com/TehShrike/deepmerge/releases/tag/v1.4.0) - api: instead of only exporting a UMD module, expose a UMD module with `pkg.main`, a CJS module with `pkg.browser`, and an ES module with `pkg.module` [#62](https://github.com/TehShrike/deepmerge/pull/62) # [1.3.2](https://github.com/TehShrike/deepmerge/releases/tag/v1.3.2) - documentation: note the minified/gzipped file sizes [56](https://github.com/TehShrike/deepmerge/pull/56) - documentation: make data structures more readable in merge example: pull request [57](https://github.com/TehShrike/deepmerge/pull/57) # [1.3.1](https://github.com/TehShrike/deepmerge/releases/tag/v1.3.1) - documentation: clarify and test some array merging documentation: pull request [51](https://github.com/TehShrike/deepmerge/pull/51) # [1.3.0](https://github.com/TehShrike/deepmerge/releases/tag/v1.3.0) - feature: `merge.all`, a merge function that merges any number of objects: pull request [50](https://github.com/TehShrike/deepmerge/pull/50) # [1.2.0](https://github.com/TehShrike/deepmerge/releases/tag/v1.2.0) - fix: an error that would be thrown when an array would be merged onto a truthy non-array value: pull request [46](https://github.com/TehShrike/deepmerge/pull/46) - feature: the ability to clone: Issue [28](https://github.com/TehShrike/deepmerge/issues/28), pull requests [44](https://github.com/TehShrike/deepmerge/pull/44) and [48](https://github.com/TehShrike/deepmerge/pull/48) - maintenance: added tests + travis to `.npmignore`: pull request [47](https://github.com/TehShrike/deepmerge/pull/47) # [1.1.1](https://github.com/TehShrike/deepmerge/releases/tag/v1.1.1) - fix an issue where an error was thrown when merging an array onto a non-array: [Pull request 46](https://github.com/TehShrike/deepmerge/pull/46) # [1.1.0](https://github.com/TehShrike/deepmerge/releases/tag/v1.1.0) - allow consumers to specify their own array merging algorithm: [Pull request 37](https://github.com/TehShrike/deepmerge/pull/37) # [1.0.3](https://github.com/TehShrike/deepmerge/releases/tag/v1.0.3) - adding bower.json back: [Issue 38](https://github.com/TehShrike/deepmerge/pull/38) - updating keywords and Github links in package.json [bc3898e](https://github.com/TehShrike/deepmerge/commit/bc3898e587a56f74591328f40f656b0152c1d5eb) # [1.0.2](https://github.com/TehShrike/deepmerge/releases/tag/v1.0.2) - Updating the readme: dropping bower, testing that the example works: [7102fc](https://github.com/TehShrike/deepmerge/commit/7102fcc4ddec11e2d33205866f9f18df14e5aeb5) # [1.0.1](https://github.com/TehShrike/deepmerge/releases/tag/v1.0.1) - `null`, dates, and regular expressions are now properly merged in arrays: [Issue 18](https://github.com/TehShrike/deepmerge/pull/18), plus commit: [ef1c6b](https://github.com/TehShrike/deepmerge/commit/ef1c6bac8350ba12a24966f0bc7da02560827586) # 1.0.0 - Should only be a patch change, because this module is READY. [Issue 15](https://github.com/TehShrike/deepmerge/issues/15) - Regular expressions are now treated like primitive values when merging: [Issue 30](https://github.com/TehShrike/deepmerge/pull/30) - Dates are now treated like primitives when merging: [Issue 31](https://github.com/TehShrike/deepmerge/issues/31)