116 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			Go
		
	
	
	
			
		
		
	
	
			116 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			Go
		
	
	
	
/*
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Package semver provides the ability to work with Semantic Versions (http://semver.org) in Go.
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Specifically it provides the ability to:
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    * Parse semantic versions
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    * Sort semantic versions
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    * Check if a semantic version fits within a set of constraints
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    * Optionally work with a `v` prefix
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Parsing Semantic Versions
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To parse a semantic version use the `NewVersion` function. For example,
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    v, err := semver.NewVersion("1.2.3-beta.1+build345")
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If there is an error the version wasn't parseable. The version object has methods
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to get the parts of the version, compare it to other versions, convert the
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version back into a string, and get the original string. For more details
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please see the documentation at https://godoc.org/github.com/Masterminds/semver.
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Sorting Semantic Versions
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A set of versions can be sorted using the `sort` package from the standard library.
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For example,
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    raw := []string{"1.2.3", "1.0", "1.3", "2", "0.4.2",}
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    vs := make([]*semver.Version, len(raw))
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	for i, r := range raw {
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		v, err := semver.NewVersion(r)
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		if err != nil {
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			t.Errorf("Error parsing version: %s", err)
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		}
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		vs[i] = v
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	}
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	sort.Sort(semver.Collection(vs))
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Checking Version Constraints
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Checking a version against version constraints is one of the most featureful
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parts of the package.
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    c, err := semver.NewConstraint(">= 1.2.3")
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    if err != nil {
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        // Handle constraint not being parseable.
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    }
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    v, _ := semver.NewVersion("1.3")
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    if err != nil {
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        // Handle version not being parseable.
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    }
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    // Check if the version meets the constraints. The a variable will be true.
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    a := c.Check(v)
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Basic Comparisons
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There are two elements to the comparisons. First, a comparison string is a list
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of comma separated and comparisons. These are then separated by || separated or
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comparisons. For example, `">= 1.2, < 3.0.0 || >= 4.2.3"` is looking for a
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comparison that's greater than or equal to 1.2 and less than 3.0.0 or is
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greater than or equal to 4.2.3.
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The basic comparisons are:
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    * `=`: equal (aliased to no operator)
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    * `!=`: not equal
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    * `>`: greater than
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    * `<`: less than
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    * `>=`: greater than or equal to
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    * `<=`: less than or equal to
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Hyphen Range Comparisons
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There are multiple methods to handle ranges and the first is hyphens ranges.
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These look like:
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    * `1.2 - 1.4.5` which is equivalent to `>= 1.2, <= 1.4.5`
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    * `2.3.4 - 4.5` which is equivalent to `>= 2.3.4, <= 4.5`
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Wildcards In Comparisons
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The `x`, `X`, and `*` characters can be used as a wildcard character. This works
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for all comparison operators. When used on the `=` operator it falls
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back to the pack level comparison (see tilde below). For example,
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    * `1.2.x` is equivalent to `>= 1.2.0, < 1.3.0`
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    * `>= 1.2.x` is equivalent to `>= 1.2.0`
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    * `<= 2.x` is equivalent to `<= 3`
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    * `*` is equivalent to `>= 0.0.0`
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Tilde Range Comparisons (Patch)
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The tilde (`~`) comparison operator is for patch level ranges when a minor
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version is specified and major level changes when the minor number is missing.
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For example,
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    * `~1.2.3` is equivalent to `>= 1.2.3, < 1.3.0`
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    * `~1` is equivalent to `>= 1, < 2`
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    * `~2.3` is equivalent to `>= 2.3, < 2.4`
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    * `~1.2.x` is equivalent to `>= 1.2.0, < 1.3.0`
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    * `~1.x` is equivalent to `>= 1, < 2`
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Caret Range Comparisons (Major)
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The caret (`^`) comparison operator is for major level changes. This is useful
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when comparisons of API versions as a major change is API breaking. For example,
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    * `^1.2.3` is equivalent to `>= 1.2.3, < 2.0.0`
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    * `^1.2.x` is equivalent to `>= 1.2.0, < 2.0.0`
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    * `^2.3` is equivalent to `>= 2.3, < 3`
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    * `^2.x` is equivalent to `>= 2.0.0, < 3`
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*/
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package semver
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