Better workflow than npm | yarn link for package authors.

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 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 Yarn workspaces.
• yalc creates a special yalc.lock file in your project (similar to yarn.lock and package.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:

npm i yalc -g

Using Yarn:

yarn global add yalc

Some documented features might not has been published yet, see 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.
• It will run preyalc or prepublish scripts before, and postyalc or postpublish after. Use --force 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.
• --files flag will show included files in published package
• 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.

• 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 during updates it will not affect newly published versions.
• 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 (read below in Advanced usage section)

• 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.
• While update if yalc'ed package has scripts.postupdate this command will run in host package dir.

• 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.

NB! Currently, yalc copies (or links) added/updated package content to the node_modules folder, but it doesn't execute yarn/npm install/update commands after this, so dependencies must be updated manually if necessary.

• 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):
  • force options is true by default, so it won't run pre/post scripts (may change this with --no-force flag).
• scripts.postupdate will be executed in host package dir, like while update operation.
• With --changed flag yalc will first check if package content has changed before publishing and pushing, it is quick operation, maybe useful for file watching scenarios with pushing on changes.

• If you are using yalc'ed modules temporary while development, first add .yalc and yalc.lock to .gitignore.
• Use yalc link, that won't touch packages.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 for yalc'ed dependencies and exits with 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 excluded 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 package-dir will perform publish operation in nestedpackage` folder of current working dir.

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 in an explicit command for this yalc installations clean [package].

• 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

WTF.