style: address lint errors

action.yml

@@ -32,4 +32,4 @@ runs:
       env:
         DIFF_PATHS: ${{ inputs.pathspec }}
         BASE_SHA: ${{ github.event.pull_request.base.sha }}
-      run: ${{ github.action_path }}/scripts/index.sh ${{ inputs.file }}
+      run: ${{ github.action_path }}/scripts/index.sh

docs/README.md

@@ -41,7 +41,7 @@ jobs:
           echo "this step will only run if specific files have changed"
 ```
 
-> ⚠️ when running on `push` events, a `fetch-depth` of `0` higher is required.
+> ⚠️ when running on `push` events, a `fetch-depth` of `0` or higher is required.
 
 ## `push` vs `pull_request`
 

scripts/index.sh

@@ -6,12 +6,12 @@ if [[ $GITHUB_EVENT_NAME != "push" && $GITHUB_EVENT_NAME != "pull_request" ]]; t
 fi
 
 if [[ -z $BASE_SHA && $GITHUB_EVENT_NAME == "push" ]]; then
-  BASE_SHA="HEAD~$(jq '.commits | length' "$GITHUB_EVENT_PATH")" # push events
+  BASE_SHA="HEAD~$(jq '.commits | length' "${GITHUB_EVENT_PATH}")" # push events
 fi
 
-CHANGED=$(git diff --exit-code --quiet ${BASE_SHA} HEAD -- $DIFF_PATHS && echo 'false' || echo 'true')
-FILES=$(git diff --name-only ${BASE_SHA} HEAD -- $DIFF_PATHS | tr '\n' ' ')
+CHANGED="$(git diff --exit-code --quiet "${BASE_SHA}" HEAD -- "${DIFF_PATHS}" && echo 'false' || echo 'true')"
+FILES="$(git diff --name-only "${BASE_SHA}" HEAD -- "${DIFF_PATHS}" | tr '\n' ' ')"
 
 echo "::set-output name=changed::${CHANGED}"
 echo "::set-output name=files::${FILES}"
-echo "::set-output name=json::$(jq --compact-output --null-input '$ARGS.positional' --args -- ${FILES})"
+echo "::set-output name=json::$(jq --compact-output --null-input '$ARGS.positional' --args -- "${FILES}")"