Fix issue when append_to_pre_release_tag is set (#38)

* If append_to_prerelease_tag is set it should be used as identifier to lookup the latest prerelease tag.

* 5.0.1

* small refactor

Author: Moritz Schmitz von Hülst

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "github-tag-action",
-  "version": "5.0.0",
+  "version": "5.0.1",
   "private": true,
   "description": "A GitHub Action to automatically bump and tag master, on merge, with the latest SemVer formatted version.",
   "main": "lib/main.js",

package.json

@@ -43,11 +43,12 @@ async function run() {
       .some((branch) => currentBranch.match(branch));
     const isPrerelease = !isReleaseBranch && isPreReleaseBranch;
 
+    const identifier = appendToPreReleaseTag ? appendToPreReleaseTag : currentBranch;
     const validTags = await getValidTags();
     const latestTag = getLatestTag(validTags);
     const latestPrereleaseTag = getLatestPrereleaseTag(
       validTags,
-      currentBranch
+      identifier
     );
 
     const commits = await getCommits(latestTag.commit.sha);
@@ -94,7 +95,7 @@ async function run() {
       const incrementedVersion = inc(
         previousTag,
         releaseType,
-        appendToPreReleaseTag ? appendToPreReleaseTag : currentBranch
+        identifier
       );
 
       if (!incrementedVersion) {