Support semver pre-releases (https://semver.org/#spec-item-11)

entrypoint.sh

@@ -74,7 +74,7 @@ function translateDockerTag() {
   elif isOnMaster; then
     TAGS="latest"
   elif isGitTag && usesBoolean "${INPUT_TAG_SEMVER}" && isSemver "${GITHUB_REF}"; then
-    TAGS=$(echo ${GITHUB_REF} | sed -e "s/refs\/tags\///g" | sed -E "s/v?([0-9]+)\.([0-9+])\.([0-9]+)/\1.\2.\3 \1.\2 \1/g")
+    TAGS=$(echo ${GITHUB_REF} | sed -e "s/refs\/tags\///g" | sed -E "s/v?([0-9]+)\.([0-9+])\.([0-9]+)(-[a-zA-Z]+(\.[0-9]+)?)?/\1.\2.\3\4 \1.\2\4 \1\4/g")
   elif isGitTag && usesBoolean "${INPUT_TAG_NAMES}"; then
     TAGS=$(echo ${GITHUB_REF} | sed -e "s/refs\/tags\///g")
   elif isGitTag; then
@@ -132,7 +132,7 @@ function usesBoolean() {
 }
 
 function isSemver() {
-  echo "${1}" | grep -Eq '^refs/tags/v?([0-9]+)\.([0-9+])\.([0-9]+)$'
+  echo "${1}" | grep -Eq '^refs/tags/v?([0-9]+)\.([0-9+])\.([0-9]+)(-[a-zA-Z]+(\.[0-9]+)?)?$'
 }
 
 function useSnapshot() {

test.bats

@@ -115,6 +115,29 @@ teardown() {
 /usr/local/bin/docker logout"
 }
 
+@test "with tag semver it pushes tags using the pre-releases" {
+  # https://semver.org/#spec-item-11
+
+  SUFFIXES=('alpha.1' 'alpha' 'ALPHA' 'ALPHA.11' 'beta' 'rc.11')
+  for SUFFIX in "${SUFFIXES[@]}"
+  do
+    export GITHUB_REF="refs/tags/v1.1.1-${SUFFIX}"
+    export INPUT_TAG_SEMVER="true"
+
+    run /entrypoint.sh
+
+    expectStdOutContains "::set-output name=tag::1.1.1-${SUFFIX}"
+
+    expectMockCalled "/usr/local/bin/docker login -u USERNAME --password-stdin
+/usr/local/bin/docker build -t my/repository:1.1.1-${SUFFIX} -t my/repository:1.1-${SUFFIX} -t my/repository:1-${SUFFIX} .
+/usr/local/bin/docker push my/repository:1.1.1-${SUFFIX}
+/usr/local/bin/docker push my/repository:1.1-${SUFFIX}
+/usr/local/bin/docker push my/repository:1-${SUFFIX}
+/usr/local/bin/docker inspect --format={{index .RepoDigests 0}} my/repository:1.1.1-${SUFFIX}
+/usr/local/bin/docker logout"
+  done
+}
+
 @test "with tag semver it pushes tags without 'v' prefix" {
   export GITHUB_REF='refs/tags/1.2.34'
   export INPUT_TAG_SEMVER="true"