Did alot of things...

go.mod

@@ -7,3 +7,5 @@ require (
 	github.com/hashicorp/go-version v1.2.1
 	golang.org/x/oauth2 v0.0.0-20200902213428-5d25da1a8d43
 )
+
+replace github.com/hashicorp/go-version v1.2.1 => github.com/BESTSELLER/go-version v1.2.4

go.sum

@@ -31,6 +31,8 @@ cloud.google.com/go/storage v1.6.0/go.mod h1:N7U0C8pVQ/+NIKOBQyamJIeKQKkZ+mxpohl
 cloud.google.com/go/storage v1.8.0/go.mod h1:Wv1Oy7z6Yz3DshWRJFhqM/UCfaWIRTdp0RXyy7KQOVs=
 cloud.google.com/go/storage v1.10.0/go.mod h1:FLPqc6j+Ki4BU591ie1oL6qBQGu2Bl/tZ9ullr3+Kg0=
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
+github.com/BESTSELLER/go-version v1.2.4 h1:vbZHa7E+Tb9jDzRrY6Il5NwkMmTAh7ZD/y+P9kfasdE=
+github.com/BESTSELLER/go-version v1.2.4/go.mod h1:kIEnnikGprffCYsIfePinaNlxCt8udBYODNKm/dFBbs=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
@@ -80,6 +82,7 @@ github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMyw
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.4.1/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.1 h1:JFrFEBb2xKufg6XkJsJr+WbKb4FQlURi5RUcBveYu9k=
 github.com/google/go-cmp v0.5.1/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-github/v32 v32.1.0 h1:GWkQOdXqviCPx7Q7Fj+KyPoGm4SwHRh8rheoPhd27II=
 github.com/google/go-github/v32 v32.1.0/go.mod h1:rIEpZD9CTDQwDK9GDrtMTycQNA4JU3qBsCizh3q2WCI=
@@ -97,8 +100,6 @@ github.com/google/pprof v0.0.0-20200708004538-1a94d8640e99/go.mod h1:ZgVRPoUq/hf
 github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
 github.com/googleapis/gax-go/v2 v2.0.4/go.mod h1:0Wqv26UfaUD9n4G6kQubkQ+KchISgw+vpHVxEJEs9eg=
 github.com/googleapis/gax-go/v2 v2.0.5/go.mod h1:DWXyrwAJ9X0FpwwEdw+IPEYBICEFu5mhpdKc/us6bOk=
-github.com/hashicorp/go-version v1.2.1 h1:zEfKbn2+PDgroKdiOzqiE8rsmLqU2uwi5PB5pBJ3TkI=
-github.com/hashicorp/go-version v1.2.1/go.mod h1:fltr4n8CU8Ke44wwGCBoEymUuxUHl09ZGVZPK5anwXA=
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
@@ -278,6 +279,7 @@ golang.org/x/tools v0.0.0-20200825202427-b303f430e36d/go.mod h1:njjCfa9FT2d7l9Bc
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/api v0.4.0/go.mod h1:8k5glujaEP+g9n7WNsDg8QP6cUVNI86fCNMcbazEtwE=
 google.golang.org/api v0.7.0/go.mod h1:WtwebWUNSVBH/HAw79HIFXZNqEvBhG+Ra+ax0hx3E3M=

releasediff.go

@@ -14,13 +14,14 @@ import (
 
 // GitHubReleases holds the two releases to compare
 type GitHubReleases struct {
-	Owner              string         // REQUIRED. Owner of the repo.
-	Repo               string         // REQUIRED. Name of the repo.
-	Release1           string         // REQUIRED. Tag name of the release you want to check.
-	Release2           string         // Tag name of the release you want to compare with. If empty, newest version will be used.
-	Filter             string         // Regex to to filter releases on. Keep empty if you want all releases.
-	IncludePreReleases bool           // Whether to include pre-releases or not. Default is false.
-	Client             *github.Client // Github client used to make the calls to the github api.
+	Owner              string             // REQUIRED. Owner of the repo.
+	Repo               string             // REQUIRED. Name of the repo.
+	Release1           string             // REQUIRED. Tag name of the release you want to check.
+	Release2           string             // Tag name of the release you want to compare with. If empty, newest version will be used.
+	Filter             string             // Regex to to filter releases on. Keep empty if you want all releases.
+	IncludePreReleases bool               // Whether to include pre-releases or not. Default is false.
+	Client             *github.Client     // Github client used to make the calls to the github api.
+	Versions           []*version.Version // Ordered list of all versions
 }
 
 // Options is optional stuff that can be sent when calling "New"
@@ -30,8 +31,22 @@ type Options struct {
 	VerifyRelease      bool   // Whether to verify that the provided versions exists as a release.
 }
 
+func getVersions(releases []*github.RepositoryRelease) []*version.Version {
+	versions := make([]*version.Version, len(releases))
+	for i, raw := range releases {
+		v, err := version.NewVersion(raw.GetTagName())
+		if err != nil {
+			fmt.Println(err)
+		}
+		versions[i] = v
+	}
+	sort.Sort(version.Collection(versions))
+
+	return versions
+}
+
 // New creates a new GitHubReleases
-func New(client *github.Client, owner string, repo string, release1 string, release2 string, options *Options) (*GitHubReleases, error) {
+func New(client *github.Client, owner string, repo string, release1 string, release2 string, options *Options) (*GitHubReleases, *github.Response, error) {
 	missingFields := []string{}
 	if owner == "" {
 		missingFields = append([]string{"Owner"}, missingFields...)
@@ -43,7 +58,7 @@ func New(client *github.Client, owner string, repo string, release1 string, rele
 		missingFields = append([]string{"Release1"}, missingFields...)
 	}
 	if len(missingFields) > 0 {
-		return nil, fmt.Errorf("Missing required field(s): %s", missingFields)
+		return nil, nil, fmt.Errorf("Missing required field(s): %s", missingFields)
 	}
 
 	var verify bool
@@ -55,22 +70,33 @@ func New(client *github.Client, owner string, repo string, release1 string, rele
 		filter = options.Filter
 	}
 
+	ctx := context.Background()
+	releases, response, err := getAllReleases(ctx, client, owner, repo, 1)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	if filter != "" {
+		releases = filterReleases(releases, filter)
+	}
+
+	if !prerelease {
+		releases = removePreReleases(releases)
+	}
+
 	// Check if Release1 is a valid release
 	if !isRelase(client, owner, repo, release1, verify) {
-		return nil, fmt.Errorf("'%s' is not a release on %s/%s", release1, owner, repo)
+		return nil, nil, fmt.Errorf("'%s' is not a release on %s/%s", release1, owner, repo)
 	}
+	versions := getVersions(releases)
 
 	// if release2 is empty we will use the latest version
 	if release2 == "" {
-		latest, _, err := client.Repositories.GetLatestRelease(context.Background(), owner, repo)
-		if err != nil {
-			return nil, err
-		}
-		release2 = latest.GetTagName()
+		release2 = versions[len(versions)-1].Original()
 	} else {
 		// Check if Release2 is a valid release
 		if !isRelase(client, owner, repo, release1, verify) {
-			return nil, fmt.Errorf("'%s' is not a release on %s/%s", release2, owner, repo)
+			return nil, nil, fmt.Errorf("'%s' is not a release on %s/%s", release2, owner, repo)
 		}
 	}
 
@@ -82,45 +108,37 @@ func New(client *github.Client, owner string, repo string, release1 string, rele
 		Filter:             filter,
 		IncludePreReleases: prerelease,
 		Client:             client,
-	}, nil
+		Versions:           versions,
+	}, response, nil
 }
 
 // Diff will fetch all releases until a specific release
-func (ghr *GitHubReleases) Diff() (int, *github.Response, error) {
-	ctx := context.Background()
-	releases, response, err := getAllReleases(ctx, ghr.Client, ghr.Owner, ghr.Repo, 1)
-
-	if ghr.Filter != "" {
-		releases = filterReleases(releases, ghr.Filter)
-	}
-
-	if !ghr.IncludePreReleases {
-		releases = removePreReleases(releases)
+func (ghr *GitHubReleases) Diff() int {
+	if ghr.Release1 == ghr.Release2 {
+		return 0
 	}
 
-	versions := make([]*version.Version, len(releases))
-	for i, raw := range releases {
-		v, _ := version.NewVersion(raw.GetTagName())
-		versions[i] = v
-	}
-	sort.Sort(version.Collection(versions))
-
-	index1, index2 := 0, 0
-	indexesFound := 0
-	for i := len(versions) - 1; i > 0; i-- {
+	index1, index2, indexesFound := 0, 0, 0
+	for i := len(ghr.Versions) - 1; i > 0; i-- {
 		if indexesFound == 2 {
 			break
 		}
-		if versions[i].Original() == ghr.Release1 {
+		if ghr.Versions[i].Original() == ghr.Release1 {
 			index1 = i
+			continue
 		}
-		if versions[i].Original() == ghr.Release2 {
+		if ghr.Versions[i].Original() == ghr.Release2 {
 			index2 = i
+			continue
 		}
 	}
+
 	versionsBehind := int(math.Abs(float64(index1 - index2)))
+	if versionsBehind == len(ghr.Versions)-1 {
+		versionsBehind--
+	}
 
-	return versionsBehind, response, err
+	return versionsBehind
 }
 
 // getAllReleases will fetch all releases

releasediff_test.go

@@ -18,8 +18,7 @@ func TestMain(m *testing.M) {
 	client := github.NewClient(tc)
 
 	repos := make(map[string]string)
-	repos["harbor"] = "v2.0.2"
-	repos["harbor-helm"] = "v1.5.0"
+	repos["ingress-nginx"] = "controller-v0.40.2"
 
 	var rate github.Rate
 	var wg sync.WaitGroup
@@ -29,15 +28,12 @@ func TestMain(m *testing.M) {
 		go func(name string, version string) {
 			defer wg.Done()
 
-			ghr, err := New(client, "goharbor", name, version, "", nil)
+			ghr, resp, err := New(client, "kubernetes", name, "controller-0.31.0", "controller-v0.34.1", &Options{Filter: "^controller-.*$", VerifyRelease: false})
 			if err != nil {
 				panic(err)
 			}
 
-			diff, resp, err := ghr.Diff()
-			if err != nil {
-				panic(err)
-			}
+			diff := ghr.Diff()
 			fmt.Printf("There are %d releases between %s and %s\n", diff, ghr.Release1, ghr.Release2)
 			rate = resp.Rate