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npm diff --diff=<spec-a> --diff=<spec-b>

Compares two package versions using their registry specifiers, e.g:
npm diff --diff=pkg@1.0.0 --diff=pkg@^2.0.0. It's also possible to
compare across forks of any package,
e.g: npm diff --diff=pkg@1.0.0 --diff=pkg-fork@1.0.0.

Any valid spec can be used, so that it's also possible to compare
directories or git repositories,
e.g: npm diff --diff=pkg@latest --diff=./packages/pkg

Here's an example comparing two different versions of a package named
abbrev from the registry:

npm diff --diff=abbrev@1.1.0 --diff=abbrev@1.1.1

On success, output looks like:

diff --git a/package.json b/package.json
index v1.1.0..v1.1.1 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@


 {


   "name": "abbrev",
-  "version": "1.1.0",
+  "version": "1.1.1",


   "description": "Like ruby's abbrev module, but in js",


   "author": "Isaac Z. Schlueter <i@izs.me>",


   "main": "abbrev.js",

Given the flexible nature of npm specs, you can also target local
directories or git repos just like when using npm install:

npm diff --diff=https://github.com/npm/libnpmdiff --diff=./local-path

In the example above we can compare the contents from the package installed
from the git repo at github.com/npm/libnpmdiff with the contents of the
./local-path that contains a valid package, such as a modified copy of
the original.

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npm diff (in a package directory, no arguments):

If the package is published to the registry, npm diff will fetch the
tarball version tagged as latest (this value can be configured using the
tag option) and proceed to compare the contents of files present in that
tarball, with the current files in your local file system.

This workflow provides a handy way for package authors to see what
package-tracked files have been changed in comparison with the latest
published version of that package.

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npm diff --diff=<pkg-name> (in a package directory):

When using a single package name (with no version or tag specifier) as an
argument, npm diff will work in a similar way to

`npm-outdated` and reach for the registry to figure out
what current published version of the package named <pkg-name>
will satisfy its dependent declared semver-range. Once that specific
version is known npm diff will print diff patches comparing the
current version of <pkg-name> found in the local file system with
that specific version returned by the registry.

Given a package named abbrev that is currently installed:

npm diff --diff=abbrev

That will request from the registry its most up to date version and
will print a diff output comparing the currently installed version to this
newer one if the version numbers are not the same.

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npm diff --diff=<spec-a> (in a package directory):

Similar to using only a single package name, it's also possible to declare
a full registry specifier version if you wish to compare the local version
of an installed package with the specific version/tag/semver-range provided
in <spec-a>.

An example: assuming pkg@1.0.0 is installed in the current node_modules
folder, running:

npm diff --diff=pkg@2.0.0

It will effectively be an alias to
npm diff --diff=pkg@1.0.0 --diff=pkg@2.0.0.

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npm diff --diff=<semver-a> [--diff=<semver-b>] (in a package directory):

Using npm diff along with semver-valid version numbers is a shorthand
to compare different versions of the current package.

It needs to be run from a package directory, such that for a package named
pkg running npm diff --diff=1.0.0 --diff=1.0.1 is the same as running
npm diff --diff=pkg@1.0.0 --diff=pkg@1.0.1.

If only a single argument <version-a> is provided, then the current local
file system is going to be compared against that version.

Here's an example comparing two specific versions (published to the
configured registry) of the current project directory:

npm diff --diff=1.0.0 --diff=1.1.0

• npm outdated
• npm install
• npm config
• npm registry