- The semantic versioner for npm
$ npm install semver
semver.valid(´1.2.3´) // ´1.2.3´
semver.valid(´a.b.c´) // null
semver.clean(´ =v1.2.3 ´) // ´1.2.3´
semver.satisfies(´1.2.3´, ´1.x || >=2.5.0 || 5.0.0 - 7.2.3´) // true
semver.gt(´1.2.3´, ´9.8.7´) // false
semver.lt(´1.2.3´, ´9.8.7´) // true
As a command-line utility:
$ semver -h
Usage: semver <version> [<version> [...]] [-r <range> | -i <inc> | -d <dec>]
Test if version(s) satisfy the supplied range(s), and sort them.
Multiple versions or ranges may be supplied, unless increment
or decrement options are specified. In that case, only a single
version may be used, and it is incremented by the specified level
Program exits successfully if any valid version satisfies
all supplied ranges, and prints all satisfying versions.
If no versions are valid, or ranges are not satisfied,
then exits failure.
Versions are printed in ascending order, so supplying
multiple versions to the utility will just sort them.
A "version" is described by the v2.0.0
specification found at
A leading "="
character is stripped off
The following range styles are supported:
- 1.2.3 A specific version. When nothing else will do.
Must be a full version number, with major, minor, and patch versions
specified. Note that build metadata is still ignored, so
1.2.3+build2012 will satisfy this range.
- >1.2.3 Greater than a specific version.
- <1.2.3 Less than a specific version. If there is
no prerelease tag on the version range, then no prerelease version will be
allowed either, even though these are technically "less
- >=1.2.3 Greater than or equal to. Note that
prerelease versions are NOT equal to their "normal" equivalents,
so 1.2.3-beta will not satisfy this range, but 2.3.0-beta
- <=1.2.3 Less than or equal to. In this case,
prerelease versions ARE allowed, so 1.2.3-beta would satisfy.
- 1.2.3 - 2.3.4 := >=1.2.3 <=2.3.4
- ~1.2.3 := >=1.2.3-0 <1.3.0-0
"Reasonably close to 1.2.3". When using tilde operators,
prerelease versions are supported as well, but a prerelease of the next
significant digit will NOT be satisfactory, so 1.3.0-beta will not
- ^1.2.3 := >=1.2.3-0 <2.0.0-0
"Compatible with 1.2.3". When using caret operators,
anything from the specified version (including prerelease) will be
supported up to, but not including, the next major version (or its
prereleases). 1.5.1 will satisfy ^1.2.3, while 1.2.2
and 2.0.0-beta will not.
- ^0.1.3 := >=0.1.3-0 <0.2.0-0
"Compatible with 0.1.3". 0.x.x versions are
special: the first non-zero component indicates potentially breaking
changes, meaning the caret operator matches any version with the same
first non-zero component starting at the specified version.
- ^0.0.2 := =0.0.2 "Only the version
0.0.2 is considered compatible"
- ~1.2 := >=1.2.0-0 <1.3.0-0 "Any
version starting with 1.2"
- ^1.2 := >=1.2.0-0 <2.0.0-0 "Any
version compatible with 1.2"
- 1.2.x := >=1.2.0-0 <1.3.0-0 "Any
version starting with 1.2"
- 1.2.* Same as 1.2.x.
- 1.2 Same as 1.2.x.
- ~1 := >=1.0.0-0 <2.0.0-0 "Any
version starting with 1"
- ^1 := >=1.0.0-0 <2.0.0-0 "Any
version compatible with 1"
- 1.x := >=1.0.0-0 <2.0.0-0 "Any
version starting with 1"
- 1.* Same as 1.x.
- 1 Same as 1.x.
- * Any version whatsoever.
- x Same as *.
- "" (just an empty string) Same as
Ranges can be joined with either a space (which implies "and") or a
(which implies "or").
All methods and classes take a final loose
boolean argument that, if
true, will be more forgiving about not-quite-valid semver strings. The
resulting output will always be 100% strict, of course.
Strict-mode Comparators and Ranges will be strict about the SemVer strings that
- valid(v): Return the parsed version, or null if
it´s not valid.
- premajor in one call will bump the version up to the
next major version and down to a prerelease of that major version.
preminor, and prepatch work the same way.
- If called from a non-prerelease version, the
prerelease will work the same as prepatch. It increments the
patch version, then makes a prerelease. If the input version is already a
prerelease it simply increments it.
- gt(v1, v2): v1 > v2
- gte(v1, v2): v1 >= v2
- lt(v1, v2): v1 < v2
- lte(v1, v2): v1 <= v2
- eq(v1, v2): v1 == v2 This is true if
they´re logically equivalent, even if they´re not the exact
same string. You already know how to compare strings.
- neq(v1, v2): v1 != v2 The opposite of
- cmp(v1, comparator, v2): Pass in a comparison
string, and it´ll call the corresponding function above.
"===" and "!==" do simple string
comparison, but are included for completeness. Throws if an invalid
comparison string is provided.
- compare(v1, v2): Return 0 if v1 == v2,
or 1 if v1 is greater, or -1 if v2 is greater.
Sorts in ascending order if passed to Array.sort().
- rcompare(v1, v2): The reverse of compare. Sorts an
array of versions in descending order when passed to
- validRange(range): Return the valid range or null if
it´s not valid
- satisfies(version, range): Return true if the
version satisfies the range.
- maxSatisfying(versions, range): Return the highest
version in the list that satisfies the range, or null if none of
- gtr(version, range): Return true if version
is greater than all the versions possible in the range.
- ltr(version, range): Return true if version
is less than all the versions possible in the range.
- outside(version, range, hilo): Return true if the
version is outside the bounds of the range in either the high or low
direction. The hilo argument must be either the string
´>´ or ´<´. (This is the
function called by gtr and ltr.)
Note that, since ranges may be non-contiguous, a version might not be greater
than a range, less than a range, or
satisfy a range! For example, the
range 1.2 <1.2.9 || >2.0.0
would have a hole from 1.2.9
, so the version 1.2.10
would not be greater than the
range (because 2.0.1
satisfies, which is higher), nor less than the
range (since 1.2.8
satisfies, which is lower), and it also does not
satisfy the range.
If you want to know if a version satisfies or does not satisfy a range, use the