Add custom source sha (#126)

Co-authored-by: Tonye Jack <jtonye@ymail.com>

.github/workflows/test.yml

@@ -130,3 +130,13 @@ jobs:
           echo "${{ toJSON(steps.changed-files-specific-comma.outputs) }}"
         shell:
           bash
+      - name: Run changed-files with custom sha
+        id: changed-files-custom-sha
+        uses: ./
+        with:
+          sha: ${{ github.event.pull_request.head.sha }}
+      - name: Show output
+        run: |
+          echo "${{ toJSON(steps.changed-files-custom-sha.outputs) }}"
+        shell:
+          bash

README.md

@@ -149,6 +149,11 @@ jobs:
          if: steps.changed-files-specific.outputs.any_changed == 'true'
          run: |
            echo "One or more files listed above has changed."
+      - name: Use a different commit SHA as the base
+        id: changed-files-comma
+        uses: tj-actions/changed-files@v8.4
+        with:
+          sha: ${{ github.event.pull_request.head.sha }}
         
 ```
 

action.yml

@@ -14,6 +14,10 @@ inputs:
     description: 'Check for changes using only this list of files (Defaults to the entire repo)'
     required: false
     default: ""
+  sha:
+    description: 'Specify a different commit SHA to be used for comparing changes'
+    required: true
+    default: ${{ github.sha }}
 
 outputs:
   added_files:
@@ -58,11 +62,11 @@ runs:
       id: changed-files
       shell: bash
       env:
-        GITHUB_SHA: ${{ github.sha }}
         GITHUB_BASE_REF: ${{ github.base_ref }}
         GITHUB_REPOSITORY: ${{ github.repository }}
         # INPUT_<VARIABLE_NAME> is not available in Composite run steps
         # https://github.community/t/input-variable-name-is-not-available-in-composite-run-steps/127611
+        INPUT_SHA: ${{ inputs.sha }}
         INPUT_TOKEN: ${{ inputs.token }}
         INPUT_FILES: ${{ inputs.files }}
         INPUT_SEPARATOR: ${{ inputs.separator }}

entrypoint.sh

@@ -8,10 +8,10 @@ git remote set-url origin "https://${INPUT_TOKEN}@github.com/${GITHUB_REPOSITORY
 
 echo "Getting HEAD info..."
 
-if [[ -z $GITHUB_SHA ]]; then
+if [[ -z $INPUT_SHA ]]; then
   CURR_SHA=$(git rev-parse HEAD 2>&1) && exit_status=$? || exit_status=$?
 else
-  CURR_SHA=$GITHUB_SHA
+  CURR_SHA=$INPUT_SHA
 fi
 
 if [[ $exit_status -ne 0 ]]; then