When developing and authoring multiple packages (private or public), you often find yourself in need of using the latest/WIP versions in other projects that you are working on in your local environment without publishing those packages to the remote registry. NPM and Yarn address this issue with a similar approach of symlinked packages (npm/yarn link). Though this may work in many cases, it often brings nasty constraints and problems with dependency resolution, symlink interoperability between file systems, etc.

- yalc acts as very simple local repository for your locally developed packages that you want to share across your local environment.

- When you run yalc publish in the package directory, it grabs only files that should be published to NPM and _puts_ them in a special global store (located, for example, in ~/.yalc).

- When you run yalc add my-package in your project it _pulls_ package content into .yalc in the current folder and injects a file:/link: dependency into package.json. Alternatively, you may use yalc link my-package which will create a symlink to the package content in node_modules and will not touch package.json (like npm/yarn link does), or you even may use it with Pnmp/Yarn/Npm workspaces.

- yalc creates a special yalc.lock file in your project (similar to yarn.lock and package-lock.json) that is used to ensure consistency while performing yalc's routines.

- yalc can be used with projects where yarn or npm package managers are used

  for managing package.json dependencies.

Using NPM:

Using Yarn:

Some documented features might not have been published yet, see the change log.

- Run yalc publish in your dependency package my-package.

- It will copy all the files that should be published in remote NPM registry.

- If your package has any of these lifecycle scripts: prepublish, prepare, prepublishOnly, prepack, preyalcpublish, they will run before in this order. If your package has any of these: postyalcpublish, postpack, publish, postpublish, they will run after in this order. Use --no-scripts to publish without running scripts.

- While copying package content, yalc calculates the hash signature of all files and, by default, adds this signature to the package manifest version. You can disable this by using the --no-sig option.

- You may also use .yalcignore to exclude files from publishing to yalc repo, for example, files like README.md, etc.

- --content flag will show included files in the published package

- NB! In terms of which files will be included in the package yalc fully supposed to emulate behavior of npm client (npm pack). [If you have nested .yalc folder in your package](https://github.com/whitecolor/yalc/issues/95) that you are going to publish with yalc and you use package.json files list, it should be included there explicitly.

- NB! Windows users should make sure the LF new line symbol is used in published sources; it may be needed for some packages to work correctly (for example, bin scripts). yalc won't convert line endings for you (because npm and yarn won't either).

- NB! Note that, if you want to include .yalc folder in published package content, you should add !.yalc line to .npmignore.

- Easily propagate package updates everywhere.

- Yalc by default resolve workspace: protocol in dependencies, to omit this use -no-workspace-resolve flag

- Run yalc add my-package in your dependent project, which

  will copy the current version from the store to your project's .yalc folder and inject a file:.yalc/my-package dependency into package.json.

- You may specify a particular version with yalc add my-package@version. This version will be fixed in yalc.lock and will not affect newly published versions during updates.

- Use the --link option to add a link: dependency instead of file:.

- Use the --dev option to add yalc package to dev dependencies.

- With --pure flag it will not touch package.json file, nor it will touch modules folder, this is useful for example when working with [Yarn workspaces](https://yarnpkg.com/lang/en/docs/workspaces/) (read below in _Advanced usage_ section)

- With --workspace (or -W) it will add dependency with "workspace:" protocol.

- As an alternative to add, you can use the link command which is similar to npm/yarn link, except that the symlink source will be not the global link directory but the local .yalc folder of your project.

- After yalc copies package content to .yalc folder it will create a symlink:

  project/.yalc/my-package ==> project/node_modules/my-package. It will not touch package.json in this case.

- Run yalc update my-package to update the latest version from store.

- Run yalc update to update all the packages found in yalc.lock.

- preyalc and postyalc scripts will be executed in target package on add/update operations which are performed while push

- if need to perform pre/post scripts on update of particular package use (pre|post)yalc.package-name name for script in your package.json.

- update --update (--upgrade, --up) to run package managers's update command for packages.

- Run yalc remove my-package, it will remove package info from package.json and yalc.lock

- Run yalc remove --all to remove all packages from project.

- Run yalc installations clean my-package to unpublish a package published with yalc publish

- Run yalc installations show my-package to show all packages to which my-package has been installed.

- When you run yalc add|link|update, the project's package locations are tracked and saved, so yalc knows where each package in the store is being used in your local environment.

- yalc publish --push will publish your package to the store and propagate all changes to existing yalc package installations (this will actually do update operation on the location).

- yalc push - is a use shortcut command for push operation (which will likely become your primarily used command for publication):

- scripts options is false by default, so it won't run pre/post scripts (may change this with passing --scripts flag).

- With --changed flag yalc will first check if package content has changed before publishing and pushing, it is a quick operation and may be useful for _file watching scenarios_ with pushing on changes.

- Use --replace option to force replacement of package content.

- Use preyalc and postyalc (read in update docs) to execute needed script on every push.

- Use --update to run yarn/npm/pnpm update command for pushed packages.

- If you are using yalc'ed modules temporarily during development, first add .yalc and yalc.lock to .gitignore.

- Use yalc link, that won't touch package.json

- If you use yalc add it will change package.json, and ads file:/link: dependencies, if you may want to use yalc check in the precommit hook which will check package.json foryalc'ed dependencies and exits with an error if you forgot to remove them.

- You may want to keep shared yalc'ed stuff within the projects you are working on and treat it as a part of the project's codebase. This may really simplify management and usage of shared _work in progress_ packages within your projects and help to make things consistent. So, then just do it, keep .yalc folder and yalc.lock in git.

- Replace it with published versions from remote repository when ready.

- NB! - standard non-code files like README, LICENCE etc. will be included also, so you may want to exclude them in .gitignore with a line like `/.yalc//*.md or you may use .yalcignore` not to include those files in package content.

- Useful for monorepos (projects with multiple sub-projects/packages): yalc publish some-project will perform publish operation in the ./some-project directory relative to process.cwd()

- Instead of completely removing package you may temporary set it back with yalc retreat [--all] for example before package publication to remote registry.

- After or later restore it with yalc restore.

Use if you will try to add repo in workspaces enabled package, --pure option will be used by default, so package.json and modules folder will not be touched.

Then you add yalc'ed package folder to workspaces in package.json (you may just add `.yalc/ and .yalc/@/* patterns). While update (or push) operation, packages content will be updated automatically and yarn` will care about everything else.

If you want to override default pure behavior use --no-pure flag.

- While working with yalc for some time on the dev machine you may face the situation when you have locations where you added yalc'ed packages being removed from file system, and this will cause some warning messages when yalc will try to push package to removed location. To get rid of such messages, there is an explicit command for this: yalc installations clean [package].

- You may use --store-folder flag option to override default location for storing published packages.

- Use --quiet to fully disable output (except of errors). Use --no-colors to disable colors.

- For example add workspace-resolve=false line to the .yalcrc file to turn off workspace: protocol resolution or sig=false to disable package version hash signature.

- yarn probably shouldn't cache packages resolved with a file path

- "yarn knit": a better "yarn link"

- npm-link-shared

- yarn link does not install package dependencies

- [[npm] RFC: file: specifier changes](https://github.com/npm/npm/pull/15900)

WTF.