see https://semver.org/#is-there-a-suggested-regular-expression-regex…

…-to-check-a-semver-string

.github/workflows/bumpup.yml

@@ -30,7 +30,7 @@ jobs:
       env:
         VERSION: ${{ github.event.inputs.gem-version }}
       run: |
-        regex="\(0\|[1-9][0-9]*\).\(0\|[1-9][0-9]*\)\.\(0\|[1-9][0-9]*\)\.\([0-9]*\)"
+        regex="^(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-]+)*))?$"
         if [[ "${VERSION}" =~ $regex ]]; then
           echo OK
         else