Remove pre-releases from release_notes

Initially the release notes were being generated from the current tagged
release (n) and the n-1 release, irrespective of whether n-1 was a full
release.  This change causes `getWorkingReleases()` to ignore any previous
releases where `PreRelease` is set to `true`.  The processing beyond this
determination will continue to consider all commits between the two identified
points, resulting in a fuller set of changes for a full release where
Pre-Releases have occured in between.

Signed-off-by: Richard Gee <richard@technologee.co.uk>

Author: rgee0

USER_GUIDE.md

@@ -51,7 +51,7 @@ This file enables Derek usage for `rgee0` and `alexellis`, it also turns on all
 
 ### Feature: `release_notes`
 
-Derek will collate closed PRs since the last release and then put together a summary and set it for your release text body.
+Derek will collate closed PRs since the previous full release and then put together a summary and set it for your release text body.
 
 Example from [openfaas/faas-cli](https://github.com/openfaas/faas-cli/releases/tag/0.9.5):
 

handler/release_handler.go

@@ -172,19 +172,26 @@ func buildClosedPRs(client *github.Client, workingReleases WorkingRelease, owner
 func getWorkingReleases(releases []*github.RepositoryRelease, owner, repo, tag string) WorkingRelease {
 	rel := WorkingRelease{}
 
-	var count int
-	var r *github.RepositoryRelease
-
-	for count, r = range releases {
+	for position, r := range releases {
 		if r.GetTagName() == tag {
 			rel.CurrentDate = r.CreatedAt.Time
 			rel.CurrentTag = tag
 			rel.CurrentRelease = r
 
-			if count+1 < len(releases) {
-				prior := releases[count+1]
-				rel.PreviousDate = prior.CreatedAt.Time
-				rel.PreviousTag = prior.GetTagName()
+			prevRel := position + 1
+
+			for prevRel < len(releases) {
+
+				prior := releases[prevRel]
+
+				if !*prior.Prerelease {
+					rel.PreviousDate = prior.CreatedAt.Time
+					rel.PreviousTag = prior.GetTagName()
+					break
+				}
+
+				prevRel++
+
 			}
 
 			break

handler/release_handler_test.go

@@ -77,19 +77,22 @@ func Test_getWorkingReleases_TwoReleases(t *testing.T) {
 	repo := "derek"
 	tag := "0.2.0"
 	lastTag := "0.1.0"
+	prerelease := false
 
 	releases := []*github.RepositoryRelease{
 		&github.RepositoryRelease{
 			TagName: &tag,
 			CreatedAt: &github.Timestamp{
 				Time: time.Now(),
 			},
+			Prerelease: &prerelease,
 		},
 		&github.RepositoryRelease{
 			TagName: &lastTag,
 			CreatedAt: &github.Timestamp{
 				Time: time.Now().Add(time.Hour * -1),
 			},
+			Prerelease: &prerelease,
 		},
 	}
 	workingReleases := getWorkingReleases(releases, owner, repo, tag)
@@ -120,13 +123,15 @@ func Test_getWorkingReleases_OneRelease(t *testing.T) {
 	owner := "alexellis"
 	repo := "derek"
 	tag := "0.2.0"
+	prerelease := false
 
 	releases := []*github.RepositoryRelease{
 		&github.RepositoryRelease{
 			TagName: &tag,
 			CreatedAt: &github.Timestamp{
 				Time: time.Now(),
 			},
+			Prerelease: &prerelease,
 		},
 	}
 	workingReleases := getWorkingReleases(releases, owner, repo, tag)
@@ -203,3 +208,59 @@ func Test_includeCommit_WithinCurrentRange(t *testing.T) {
 		t.Fail()
 	}
 }
+
+func Test_getWorkingReleases_ThreeReleasesOnePreRelease(t *testing.T) {
+	owner := "alexellis"
+	repo := "derek"
+	tag := "0.2.0"
+	midTag := "0.1.5"
+	midPreRelease := true
+	lastTag := "0.1.0"
+	preRelease := false
+
+	releases := []*github.RepositoryRelease{
+		&github.RepositoryRelease{
+			TagName: &tag,
+			CreatedAt: &github.Timestamp{
+				Time: time.Now(),
+			},
+			Prerelease: &preRelease,
+		},
+		&github.RepositoryRelease{
+			TagName: &midTag,
+			CreatedAt: &github.Timestamp{
+				Time: time.Now().Add(time.Hour * -1),
+			},
+			Prerelease: &midPreRelease,
+		},
+		&github.RepositoryRelease{
+			TagName: &lastTag,
+			CreatedAt: &github.Timestamp{
+				Time: time.Now().Add(time.Hour * -2),
+			},
+			Prerelease: &preRelease,
+		},
+	}
+	workingReleases := getWorkingReleases(releases, owner, repo, tag)
+
+	gotCurrentDate := workingReleases.CurrentDate
+	wantCurrentDate := releases[0].GetCreatedAt().Time
+
+	if gotCurrentDate != wantCurrentDate {
+		t.Errorf("current date, got: %s, want: %s", gotCurrentDate, wantCurrentDate)
+	}
+
+	gotPreviousDate := workingReleases.PreviousDate
+	wantPreviousDate := releases[2].GetCreatedAt().Time
+
+	if gotPreviousDate != wantPreviousDate {
+		t.Errorf("previous date, got: %s, want: %s", gotPreviousDate, wantPreviousDate)
+	}
+
+	gotPreviousTag := workingReleases.PreviousTag
+	wantPreviousTag := *releases[2].TagName
+
+	if gotPreviousTag != wantPreviousTag {
+		t.Errorf("previous tag, got: %s, want: %s", gotPreviousTag, wantPreviousTag)
+	}
+}