关于semver的文档：
https://docs.npmjs.com/cli/v6/using-npm/semver
了解一下 Range Grammar, 以及Tilde Ranges 和Caret Ranges
摘要
Tilde Ranges ~1.2.3 ~1.2 ~1 Allows patch-level changes if a minor version is specified on the comparator. Allows minor-level changes if not. ~1.2.3 := >=1.2.3 <1.(2+1).0 := >=1.2.3 <1.3.0 ~1.2 := >=1.2.0 <1.(2+1).0 := >=1.2.0 <1.3.0 (Same as 1.2.x) ~1 := >=1.0.0 <(1+1).0.0 := >=1.0.0 <2.0.0 (Same as 1.x) ~0.2.3 := >=0.2.3 <0.(2+1).0 := >=0.2.3 <0.3.0 ~0.2 := >=0.2.0 <0.(2+1).0 := >=0.2.0 <0.3.0 (Same as 0.2.x) ~0 := >=0.0.0 <(0+1).0.0 := >=0.0.0 <1.0.0 (Same as 0.x) ~1.2.3-beta.2 := >=1.2.3-beta.2 <1.3.0 Note that prereleases in the 1.2.3 version will be allowed, if they are greater than or equal to beta.2. So, 1.2.3-beta.4 would be allowed, but 1.2.4-beta.2 would not, because it is a prerelease of a different [major, minor, patch] tuple. 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. In other words, this allows patch and minor updates for versions 1.0.0 and above, patch updates for versions 0.X >=0.1.0, and no updates for versions 0.0.X. Many authors treat a 0.x version as if the x were the major "breaking-change" indicator. Caret ranges are ideal when an author may make breaking changes between 0.2.4 and 0.3.0 releases, which is a common practice. However, it presumes that there will not be breaking changes between 0.2.4 and 0.2.5. It allows for changes that are presumed to be additive (but non-breaking), according to commonly observed practices. ^1.2.3 := >=1.2.3 <2.0.0 ^0.2.3 := >=0.2.3 <0.3.0 ^0.0.3 := >=0.0.3 <0.0.4 ^1.2.3-beta.2 := >=1.2.3-beta.2 <2.0.0 Note that prereleases in the 1.2.3 version will be allowed, if they are greater than or equal to beta.2. So, 1.2.3-beta.4 would be allowed, but 1.2.4-beta.2 would not, because it is a prerelease of a different [major, minor, patch] tuple. ^0.0.3-beta := >=0.0.3-beta <0.0.4 Note that prereleases in the 0.0.3 version only will be allowed, if they are greater than or equal to beta. So, 0.0.3-pr.2 would be allowed. When parsing caret ranges, a missing patch value desugars to the number 0, but will allow flexibility within that value, even if the major and minor versions are both 0. ^1.2.x := >=1.2.0 <2.0.0 ^0.0.x := >=0.0.0 <0.1.0 ^0.0 := >=0.0.0 <0.1.0 A missing minor and patch values will desugar to zero, but also allow flexibility within those values, even if the major version is zero. ^1.x := >=1.0.0 <2.0.0 ^0.x := >=0.0.0 <1.0.0 Range Grammar Putting all this together, here is a Backus-Naur grammar for ranges, for the benefit of parser authors: range-set ::= range ( logical-or range ) * logical-or ::= ( ' ' ) * '||' ( ' ' ) * range ::= hyphen | simple ( ' ' simple ) * | '' hyphen ::= partial ' - ' partial simple ::= primitive | partial | tilde | caret primitive ::= ( '<' | '>' | '>=' | '<=' | '=' ) partial partial ::= xr ( '.' xr ( '.' xr qualifier ? )? )? xr ::= 'x' | 'X' | '*' | nr nr ::= '0' | ['1'-'9'] ( ['0'-'9'] ) * tilde ::= '~' partial caret ::= '^' partial qualifier ::= ( '-' pre )? ( '+' build )? pre ::= parts build ::= parts parts ::= part ( '.' part ) * part ::= nr | [-0-9A-Za-z]+