The npm Blog

Wowowowowow npm@5!

This release marks months of hard work for the young, scrappy, and hungry CLI team, and includes some changes we’ve been hoping to do for literally years. npm@5 takes npm a pretty big step forward, significantly improving its performance in almost all common situations, fixing a bunch of old errors due to the architecture, and just generally making it more robust and fault-tolerant. It comes with changes to make life easier for people doing monorepos, for users who want consistency/security guarantees, and brings semver support to git dependencies. See below for all the deets!

Breaking Changes

• Existing npm caches will no longer be used: you will have to redownload any cached packages. There is no tool or intention to reuse old caches. (#15666)

• npm install ./packages/subdir will now create a symlink instead of a regular installation. file://path/to/tarball.tgz will not change – only directories are symlinked. (#15900)

• npm will now scold you if you capitalize its name. seriously it will fight you.

• npm will --save by default now. Additionally, package-lock.json will be automatically created unless an npm-shrinkwrap.json exists. (#15666)

• Git dependencies support semver through user/repo#semver:^1.2.3 (#15308) (#15666) (@sankethkatta)

• Git dependencies with prepare scripts will have their devDependencies installed, and npm install run in their directory before being packed.

• npm cache commands have been rewritten and don’t really work anything like they did before. (#15666)

• --cache-min and --cache-max have been deprecated. (#15666)

• Running npm while offline will no longer insist on retrying network requests. npm will now immediately fall back to cache if possible, or fail. (#15666)

• package locks no longer exclude optionalDependencies that failed to build. This means package-lock.json and npm-shrinkwrap.json should now be cross-platform. (#15900)

• If you generated your package lock against registry A, and you switch to registry B, npm will now try to install the packages from registry B, instead of A. If you want to use different registries for different packages, use scope-specific registries (npm config set @myscope:registry=https://myownregist.ry/packages/). Different registries for different unscoped packages are not supported anymore.

• Shrinkwrap and package-lock no longer warn and exit without saving the lockfile.

• Local tarballs can now only be installed if they have a file extensions .tar, .tar.gz, or .tgz.

• A new loglevel, notice, has been added and set as default.

• One binary to rule them all: ./cli.js has been removed in favor of ./bin/npm-cli.js. In case you were doing something with ./cli.js itself. (#12096) (@watilde)

• Stub file removed (#16204) (@watilde)

• The “extremely legacy” _token couchToken has been removed. (#12986)

Feature Summary

Installer changes

• A new, standardised lockfile feature meant for cross-package-manager compatibility (package-lock.json), and a new format and semantics for shrinkwrap. (#16441)

• --save is no longer necessary. All installs will be saved by default. You can prevent saving with --no-save. Installing optional and dev deps is unchanged: use -D/--save-dev and -O/--save-optional if you want them saved into those fields instead. Note that since npm@3, npm will automatically update npm-shrinkwrap.json when you save: this will also be true for package-lock.json. (#15666)

• Installing a package directory now ends up creating a symlink and does the Right Thing™ as far as saving to and installing from the package lock goes. If you have a monorepo, this might make things much easier to work with, and probably a lot faster too. 😁 (#15900)

• Project-level (toplevel) preinstall scripts now run before anything else, and can modify node_modules before the CLI reads it.

• Two new scripts have been added, prepack and postpack, which will run on both npm pack and npm publish, but NOT on npm install (without arguments). Combined with the fact that prepublishOnly is run before the tarball is generated, this should round out the general story as far as putzing around with your code before publication.

• Git dependencies with prepare scripts will now have their devDependencies installed, and their prepare script executed as if under npm pack.

• Git dependencies now support semver-based matching: npm install git://github.com/npm/npm#semver:^5 (#15308, #15666)

• node-gyp now supports node-gyp.cmd on Windows (#14568)

• npm no longer blasts your screen with the whole installed tree. Instead, you’ll see a summary report of the install that is much kinder on your shell real-estate. Specially for large projects. (#15914): $ npm install npm added 125, removed 32, updated 148 and moved 5 packages in 5.032s. $

• --parseable and --json now work more consistently across various commands, particularly install and ls.

• Indentation is now detected and preserved for package.json, package-lock.json, and npm-shrinkwrap.json. If the package lock is missing, it will default to package.json’s current indentation.

Publishing

• New publishes will now include both sha512 and sha1 checksums. Versions of npm from 5 onwards will use the strongest algorithm available to verify downloads. npm/npm-registry-client#157

Cache Rewrite!

We’ve been talking about rewriting the cache for a loooong time. So here it is. Lots of exciting stuff ahead. The rewrite will also enable some exciting future features, but we’ll talk about those when they’re actually in the works. #15666 is the main PR for all these changes. Additional PRs/commits are linked inline.

• Package metadata, package download, and caching infrastructure replaced.

• It’s a bit faster. Hopefully it will be noticeable. 🤔

• With the shrinkwrap and package-lock changes, tarballs will be looked up in the cache by content address (and verified with it).

• Corrupted cache entries will automatically be removed and re-fetched on integrity check failure.

• npm CLI now supports tarball hashes with any hash function supported by Node.js. That is, it will use sha512 for tarballs from registries that send a sha512 checksum as the tarball hash. Publishing with sha512 is added by npm/npm-registry-client#157 and may be backfilled by the registry for older entries.

• Remote tarball requests are now cached. This means that even if you’re missing the integrity field in your shrinkwrap or package-lock, npm will be able to install from the cache.

• Downloads for large packages are streamed in and out of disk. npm is now able to install packages of “”“any”“” size without running out of memory. Support for publishing them is pending (due to registry limitations).

• Automatic fallback-to-offline mode. npm will seamlessly use your cache if you are offline, or if you lose access to a particular registry (for example, if you can no longer access a private npm repo, or if your git host is unavailable).

• A new --prefer-offline option will make npm skip any conditional requests (304 checks) for stale cache data, and only hit the network if something is missing from the cache.

• A new --prefer-online option that will force npm to revalidate cached data (with 304 checks), ignoring any staleness checks, and refreshing the cache with revalidated, fresh data.

• A new --offline option will force npm to use the cache or exit. It will error with an ENOTCACHED code if anything it tries to install isn’t already in the cache.

• A new npm cache verify command that will garbage collect your cache, reducing disk usage for things you don’t need (-handwave-), and will do full integrity verification on both the index and the content. This is also hooked into npm doctor as part of its larger suite of checking tools.

• The new cache is very fault tolerant and supports concurrent access.

  • Multiple npm processes will not corrupt a shared cache.
  • Corrupted data will not be installed. Data is checked on both insertion and extraction, and treated as if it were missing if found to be corrupted. I will literally bake you a cookie if you manage to corrupt the cache in such a way that you end up with the wrong data in your installation (installer bugs notwithstanding).
  • npm cache clear is no longer useful for anything except clearing up disk space.

• Package metadata is cached separately per registry and package type: you can’t have package name conflicts between locally-installed packages, private repo packages, and public repo packages. Identical tarball data will still be shared/deduplicated as long as their hashes match.

• HTTP cache-related headers and features are “fully” (lol) supported for both metadata and tarball requests – if you have your own registry, you can define your own cache settings the CLI will obey!

• prepublishOnly now runs before the tarball to publish is created, after prepare has run.