feat: add support for passing branch name to the base_sha and sha inputs

.github/workflows/greetings.yml

@@ -7,6 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/first-interaction@v1
+        continue-on-error: true
         with:
           repo-token: ${{ secrets.GITHUB_TOKEN }}
           issue-message: "Thanks for reporting this issue, don't forget to star this project if you haven't already to help us reach a wider audience."

.github/workflows/test.yml

@@ -290,7 +290,11 @@ jobs:
     name: Test using branch names for base_sha and sha inputs
     runs-on: ubuntu-latest
     needs: build
-    if: needs.build.outputs.files_changed != 'true'
+    if: |
+      ( 
+        github.event_name == 'push' || 
+        github.event_name == 'pull_request'
+      ) && needs.build.outputs.files_changed != 'true'
 
     steps:
       - name: Checkout branch

src/commitSha.ts

@@ -5,6 +5,7 @@ import {Env} from './env'
 import {Inputs} from './inputs'
 import {
   canDiffCommits,
+  cleanShaInput,
   getCurrentBranchName,
   getHeadSha,
   getParentSha,
@@ -23,7 +24,7 @@ const getCurrentSHA = async ({
   inputs: Inputs
   workingDirectory: string
 }): Promise<string> => {
-  let currentSha = inputs.sha
+  let currentSha = await cleanShaInput(inputs.sha)
   core.debug('Getting current SHA...')
 
   if (inputs.until) {
@@ -162,7 +163,7 @@ export const getSHAForNonPullRequestEvent = async (
   }
 
   const currentSha = await getCurrentSHA({inputs, workingDirectory})
-  let previousSha = inputs.baseSha
+  let previousSha = await cleanShaInput(inputs.baseSha)
   const diff = '..'
   const currentBranchName = await getCurrentBranchName({cwd: workingDirectory})
 
@@ -390,7 +391,7 @@ export const getSHAForPullRequestEvent = async (
   }
 
   const currentSha = await getCurrentSHA({inputs, workingDirectory})
-  let previousSha = inputs.baseSha
+  let previousSha = await cleanShaInput(inputs.baseSha)
   let diff = '...'
 
   if (previousSha && currentSha && currentBranch && targetBranch) {

src/utils.ts

@@ -771,6 +771,52 @@ export const verifyCommitSha = async ({
   return exitCode
 }
 
+/**
+ * Clean the sha from the input which could be a branch name or a commit sha.
+ *
+ * If the input is a valid commit sha, return it as is.
+ *
+ * If the input is a branch name, get the HEAD sha of that branch and return it.
+ *
+ * @param sha The input string, which could be a branch name or a commit sha.
+ * @returns The cleaned SHA string.
+ * @throws Error If the input is not a valid commit sha or a branch name.
+ */
+export const cleanShaInput = async (sha: string): Promise<string> => {
+  // Check if the input is a valid commit sha
+  if (!sha) {
+    return sha
+  }
+  // Check if the input is a valid commit sha
+  const {stdout, exitCode} = await exec.getExecOutput(
+    'git',
+    ['rev-parse', '--verify', sha],
+    {
+      ignoreReturnCode: true,
+      silent: !core.isDebug()
+    }
+  )
+
+  if (exitCode !== 0) {
+    // If it's not a valid commit sha, assume it's a branch name and get the HEAD sha
+    const {stdout: stdout2, exitCode: exitCode2} = await exec.getExecOutput(
+      'git',
+      ['rev-parse', '--verify', `refs/heads/${sha}`],
+      {
+        ignoreReturnCode: true,
+        silent: !core.isDebug()
+      }
+    )
+
+    if (exitCode2 !== 0) {
+      throw new Error(`Unable to locate the commit sha: ${sha}`)
+    }
+
+    return stdout2.trim()
+  }
+
+  return stdout.trim()
+}
 export const getPreviousGitTag = async ({
   cwd
 }: {