Add support for version ranges

Fixes #62

go.mod

@@ -14,6 +14,7 @@ require (
 )
 
 require (
+	github.com/Masterminds/semver/v3 v3.1.1 // indirect
 	github.com/Microsoft/go-winio v0.4.16 // indirect
 	github.com/ProtonMail/go-crypto v0.0.0-20210428141323-04723f9f07d7 // indirect
 	github.com/VividCortex/ewma v1.1.1 // indirect

go.sum

@@ -1,3 +1,5 @@
+github.com/Masterminds/semver/v3 v3.1.1 h1:hLg3sBzpNErnxhQtUy/mmLR2I9foDujNK030IGemrRc=
+github.com/Masterminds/semver/v3 v3.1.1/go.mod h1:VPu/7SZ7ePZ3QOrcuXROw5FAcLl4a0cBrbBpGY/8hQs=
 github.com/Microsoft/go-winio v0.4.14/go.mod h1:qXqCSQ3Xa7+6tgxaGTIe4Kpcdsi+P8jBhyzoq1bpyYA=
 github.com/Microsoft/go-winio v0.4.16 h1:FtSW/jqD+l4ba5iPBj9CODVtgfYAD8w2wS923g/cFDk=
 github.com/Microsoft/go-winio v0.4.16/go.mod h1:XB6nPKklQyQ7GC9LdcBEcBl8PF76WugXOPRXwdLnMv0=

src/core/packages_repository.go

@@ -5,8 +5,10 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"sort"
 	"strings"
 
+	"github.com/Masterminds/semver/v3"
 	"github.com/go-git/go-git/v5"
 	"github.com/go-git/go-git/v5/plumbing"
 	"github.com/otiai10/copy"
@@ -72,6 +74,15 @@ func (pr *packagesRepository) GetPackageDependencies(dep ResolvedDependency) (*D
 }
 
 func (pr *packagesRepository) GetResolvedDependencySHA(dep Dependency) (string, error) {
+	if dep.Version().Kind() == SemVerRange {
+		exactDep, err := pr.getVersionMatchingSemVerRange(dep)
+		if err != nil {
+			return "", err
+		}
+
+		dep = exactDep
+	}
+
 	err := pr.ensurePackageIsReady(dep.Name(), dep.Version().Value())
 	if err != nil {
 		return "", err
@@ -87,6 +98,45 @@ func (pr *packagesRepository) GetResolvedDependencySHA(dep Dependency) (string,
 	return ref.Hash().String(), nil
 }
 
+func (pr *packagesRepository) getVersionMatchingSemVerRange(dep Dependency) (Dependency, error) {
+	repo, _, err := pr.ensurePackageIsUpToDate(dep.Name())
+	if err != nil {
+		return dep, err
+	}
+
+	// Get the latest tag that matches the semver range
+	constraint, err := semver.NewConstraint(dep.Version().Value())
+	if err != nil {
+		return nil, err
+	}
+	matchingTags := make([]*semver.Version, 0)
+	tagIter, err := repo.Tags()
+	if err != nil {
+		return nil, err
+	}
+	err = tagIter.ForEach(func(ref *plumbing.Reference) error {
+		tagName := strings.TrimPrefix(ref.Name().String(), "refs/tags/")
+		tagVersion, err := semver.NewVersion(tagName)
+		if err == nil && constraint.Check(tagVersion) {
+			matchingTags = append(matchingTags, tagVersion)
+		}
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	sort.Sort(semver.Collection(matchingTags))
+
+	if len(matchingTags) == 0 {
+		return nil, errors.New("No matching tags found for " + dep.Name())
+	}
+
+	latestMatchingTag := matchingTags[len(matchingTags)-1]
+
+	return NewDependency(dep.Name(), NewVersion(SemVerExact, latestMatchingTag.String())), nil
+}
+
 func (pr *packagesRepository) ClearCache() error {
 	return pr.removeAll(pr.getCacheDir())
 }
@@ -99,17 +149,17 @@ func (pr *packagesRepository) getPackageCacheDir(depName string) string {
 	return pr.getCacheDir() + `\` + depName
 }
 
-func (pr *packagesRepository) ensurePackageIsReady(depName string, depVersionString string) error {
+func (pr *packagesRepository) ensurePackageIsUpToDate(depName string) (*git.Repository, bool, error) {
 	packageCacheDir := pr.getPackageCacheDir(depName)
 
 	err := os.MkdirAll(packageCacheDir, os.ModePerm)
 	if err != nil {
-		return errors.New("Error creating package cache directory")
+		return nil, false, errors.New("Error creating package cache directory")
 	}
 
 	packageCloneAlreadyExisted, err := utils.FileExists(packageCacheDir + `\.git`)
 	if err != nil {
-		return errors.New("Error checking if package was cloned")
+		return nil, false, errors.New("Error checking if package was cloned")
 	}
 
 	if !packageCloneAlreadyExisted {
@@ -123,22 +173,35 @@ func (pr *packagesRepository) ensurePackageIsReady(depName string, depVersionStr
 			if err.Error() == "authentication required" {
 				message = "Error downloading package " + depName + ". Are you sure that package exists?"
 			}
-			return errors.New(message)
+			return nil, packageCloneAlreadyExisted, errors.New(message)
 		}
 	}
 
-	// Checkout the specified version
 	repo, err := git.PlainOpen(packageCacheDir)
 	if err != nil {
-		return errors.New("Error opening package")
+		return nil, packageCloneAlreadyExisted, errors.New("Error opening package")
+	}
+
+	err = repo.Fetch(&git.FetchOptions{})
+	if err != nil && err.Error() != "already up-to-date" {
+		return nil, packageCloneAlreadyExisted, errors.New("Error fetching package")
+	}
+
+	return repo, packageCloneAlreadyExisted, nil
+}
+
+func (pr *packagesRepository) ensurePackageIsReady(depName string, depVersionString string) error {
+	repo, previouslyCloned, err := pr.ensurePackageIsUpToDate(depName)
+	if err != nil {
+		return err
 	}
 
 	worktree, err := repo.Worktree()
 	if err != nil {
 		return errors.New("Error getting worktree")
 	}
 
-	if packageCloneAlreadyExisted {
+	if previouslyCloned {
 		errorMessage := "Problem fetching latest updates to package " + depName + ". Continuing from local cache."
 
 		branches, err := repo.Branches()

src/core/version.go

@@ -1,8 +1,10 @@
 package core
 
 import (
+	"ahkpm/src/invariant"
 	"ahkpm/src/utils"
 	"errors"
+	"regexp"
 	"strings"
 )
 
@@ -21,6 +23,7 @@ type version struct {
 type VersionKind string
 
 const (
+	SemVerRange VersionKind = "Semantic Version Range"
 	SemVerExact VersionKind = "Semantic Version"
 	Branch      VersionKind = "Branch"
 	Tag         VersionKind = "Tag"
@@ -52,13 +55,34 @@ func VersionFromSpecifier(versionSpecifier string) (Version, error) {
 	} else if strings.HasPrefix(versionSpecifier, "commit:") {
 		v.kind = Commit
 		v.value = strings.TrimPrefix(versionSpecifier, "commit:")
+	} else if utils.IsSemVerRange(versionSpecifier) {
+		v.kind = SemVerRange
+		v.value = getLegibleRange(versionSpecifier)
 	} else {
 		return v, errors.New("Invalid version specifier " + versionSpecifier)
 	}
 
 	return v, nil
 }
 
+// Check to see if the range is of form "1" or "1.2" to convert them
+// to equivalents "1.x.x" and "1.2.x" respectively. The goal is to make
+// the range more explicit and readable to the user before saving them.
+func getLegibleRange(versionSpecifier string) string {
+	isSimpleRange, err := regexp.Match(`^\d+\.?(\d+)?$`, []byte(versionSpecifier))
+	invariant.AssertNoError(err)
+	if isSimpleRange {
+		if strings.Contains(versionSpecifier, ".") {
+			// If it's of form "1.2", convert it to "1.2.x"
+			return versionSpecifier + ".x"
+		} else {
+			// If it's of form "1", convert it to "1.x.x"
+			return versionSpecifier + ".x.x"
+		}
+	}
+	return versionSpecifier
+}
+
 // Represents the Version as a valid version specifier string.
 func (v version) String() string {
 	if v.kind == Branch || v.kind == Tag || v.kind == Commit {

src/utils/utils.go

@@ -6,17 +6,18 @@ import (
 	"fmt"
 	"os"
 	"os/exec"
-	"regexp"
+
+	"github.com/Masterminds/semver/v3"
 )
 
 func IsSemVer(value string) bool {
-	// This regular expression is taken from semver.org
-	isMatch, err := regexp.MatchString("^(0|[1-9]\\d*)\\.(0|[1-9]\\d*)\\.(0|[1-9]\\d*)(?:-((?:0|[1-9]\\d*|\\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\\.(?:0|[1-9]\\d*|\\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\\+([0-9a-zA-Z-]+(?:\\.[0-9a-zA-Z-]+)*))?$", value)
-	if err != nil {
-		Exit("Error validating semver:")
-	}
+	_, err := semver.StrictNewVersion(value)
+	return err == nil
+}
 
-	return isMatch
+func IsSemVerRange(value string) bool {
+	_, err := semver.NewConstraint(value)
+	return err == nil
 }
 
 func Exit(msg string) {

src/utils/utils_test.go

@@ -11,5 +11,18 @@ func TestIsSemver(t *testing.T) {
 	assert.True(t, IsSemVer("1.2.3"))
 	assert.True(t, IsSemVer("1.2.3-beta.1"))
 	assert.True(t, IsSemVer("1.2.3-beta.1+build.1"))
+	assert.False(t, IsSemVer("1"))
+	assert.False(t, IsSemVer("^1.2.3"))
 	assert.False(t, IsSemVer("foobar"))
 }
+
+func TestIsSemverRange(t *testing.T) {
+	assert.True(t, IsSemVerRange("1.2.3"))
+	assert.True(t, IsSemVerRange("1.2.3-beta.1"))
+	assert.True(t, IsSemVerRange("1.2.3-beta.1+build.1"))
+	assert.True(t, IsSemVerRange("1.2.3-beta.1+build.1 || 1.2.3-beta.2"))
+	assert.True(t, IsSemVerRange("1.2.3-beta.1+build.1 || 1.2.3-beta.2 || 1.2.3-beta.3"))
+	assert.True(t, IsSemVerRange("^1.2.3"))
+	assert.True(t, IsSemVerRange("~1.2.3"))
+	assert.False(t, IsSemVerRange("foobar"))
+}