Fix "No commits between" error (#243)

source/app/action/index.mjs

@@ -320,6 +320,7 @@
               }
               catch (error) {
                 console.debug(error)
+                //Check if pull request has already been created previously
                   if (/A pull request already exists/.test(error)) {
                     info(`Pull request from ${committer.head} to ${committer.branch}`, "(already existing)")
                     const q = `repo:${github.context.repo.owner}/${github.context.repo.repo}+type:pr+state:open+Auto-generated metrics for run #${github.context.runId}+in:title`
@@ -330,6 +331,12 @@
                       throw new Error(`Found more than one matching prs: ${prs.map(({number}) => `#${number}`).join(", ")}. Cannot proceed.`)
                     ;({number} = prs.shift())
                   }
+                //Check if pull request could not been created because there are no diff between head and base
+                  else if (/No commits between/.test(error)) {
+                    info(`Pull request from ${committer.head} to ${committer.branch}`, "(no diff)")
+                    committer.merge = false
+                    number = "(none)"
+                  }
                 else
                   throw error
               }