What is the bower and npm version syntax

Question

Bower enables me to specify version requirements for packages using the following syntax    dependencies         lt name gt      lt version gt         But I have not been able to find what is the syntax to use for the  lt version gt   I know that I can specify versions to be     greater than a certain version with   gt 1 0 0  greater than or equal to a version    gt  1 0 0  or in some range   1 0 0 - 2 0 0      I also know that there is a common version syntax containing the tilde    1 0 0   But I am not sure what it means and whether it is the same as   1 0 0    I am also interested to know whether I am able to specify multiple non-consecutive versions  such as exactly 1 0 3 plus versions greater than 1 5 0  etc

User · Answer

Bower uses semver syntax  but here are a few quick examples   You can install a specific version     bower install jquery 1 11 1   You can use   to specify  any version that starts with this      bower install jquery  1 11   You can specify multiple version requirements together     bower install  jquery  lt 2 0  gt 1 10

User · Answer

You can also use the latest keyword to install the most recent version available      dependencies          fontawesome    latest

User · Answer

In a nutshell  the syntax for Bower version numbers  and NPM s  is called SemVer  which is short for  Semantic Versioning   You can find documentation for the detailed syntax of SemVer as used in Bower and NPM on the API for the semver parser within Node npm  You can learn more about the underlying spec  which does not mention   or other syntax details  at semver org   There s a super-handy visual semver calculator you can play with  making all of this much easier to grok and test   SemVer isn t just a syntax  It has some pretty interesting things to say about the right ways to publish API s  which will help to understand what the syntax means  Crucially       Once you identify your public API  you communicate changes to it with specific increments to your version number  Consider a version format of X Y Z  Major Minor Patch   Bug fixes not affecting the API increment the patch version  backwards compatible API additions changes increment the minor version  and backwards incompatible API changes increment the major version    So  your specific question about   relates to that Major Minor Patch schema   As does the related caret operator     You can use   to narrow the range of versions you re willing to accept to either    subsequent patch-level changes to the same minor version   bug fixes not affecting the API    or  subsequent minor-level changes to the same major version   backwards compatible API additions changes     For example  to indicate you ll take any subsequent patch-level changes on the 1 2 x tree  starting with 1 2 0  but less than 1 3 0  you could use    angular     1 2    or   angular     1 2 0    This also gets you the same results as using the  x syntax     angular    1 2 x    But  you can use the tilde   syntax to be even more specific  if you re only willing to accept patch-level changes starting with 1 2 4  but still less than 1 3 0  you d use    angular     1 2 4    Moving left  towards the major version  if you use      angular     1        it s the same as      angular    1 x    or   angular     1 0 0       and matches any minor- or patch-level changes above 1 0 0  and less than 2 0   Note that last variation above  it s called a  caret range   The caret looks an awful lot like a  gt   so you d be excused for thinking it means  any version greater than 1 0 0    I ve certainly slipped on that   Nope   Caret ranges are basically used to say that you care only about the left-most significant digit - usually the major version - and that you ll permit any minor- or patch-level changes that don t affect that left-most digit  Yet  unlike a tilde range that specifies a major version  caret ranges let you specify a precise minor patch starting point  So  while  1 0 0      1  a caret range such as  1 2 3 lets you say you ll take any changes  gt  1 2 3  amp  amp   lt 2 0 0  You couldn t do that with a tilde range   That all seems confusing at first  when you look at it up-close  But zoom out for a sec  and think about it this way  the caret simply lets you say that you re most concerned about whatever significant digit is left-most  The tilde lets you say you re most concerned about whichever digit is right-most  The rest is detail   It s the expressive power of the tilde and the caret that explains why people use them much more than the simpler  x syntax  they simply let you do more  That s why you ll see the tilde used often even where  x would serve  As an example  see npm itself  its own package json file includes lots of dependencies in  2 4 0 format  rather than the 2 4 x format it could use  By sticking to    the syntax is consistent all the way down a list of 70  versioned dependencies  regardless of which beginning patch number is acceptable    Anyway  there s still more to SemVer  but I won t try to detail it all here  Check it out on the node semver package s readme  And be sure to use the semantic versioning calculator while you re practicing and trying to get your head around how SemVer works      RE  Non-Consecutive Version Numbers  OP s final question seems to be about specifying non-consecutive version numbers ranges  if I have edited it fairly   Yes  you can do that  using the common double-pipe  or  operator      Like so    angular    1 2  lt   1 2 9     gt 2 0 0

User · Answer

Based on semver  you can use   Hyphen Ranges X Y Z - A B C  1 2 3-2 3 4  Indicates   1 2 3  lt  2 3 4 X-Ranges   1 2 x 1 X  1 2    Tilde Ranges   1 2 3  1 2  Indicates allowing patch-level changes or minor version changes  Caret Ranges  1 2 3  0 2 5  0 0 4  Allows changes that do not modify the left-most non-zero digit in the  major  minor  patch  tuple    1 2 x  means   1 2 0  lt 2 0 0   0 0 x  means   0 0 0  lt 0 1 0   0 0  means   0 0 0  lt 0 1 0

User · Answer

If there is no patch number    is equivalent to appending  x to the non-tilde version   If there is a patch number    allows all patch numbers    the specified one    1        1 x  1 2      1 2 x  1 2 3      gt  1 2 3  lt 1 3 0    I don t have enough points to comment on the accepted answer  but some of the tilde information is at odds with the linked semver documentation    angular     1 2  will not match 1 3  1 4  1 4 9   Also  angular     1  and  angular     1 0  are not equivalent   This can be verified with the npm semver calculator

[node.js] What is the bower (and npm) version syntax?

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