From fc7f51746699c0dacd6a3c2a8f594a18c1726336 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Thu, 16 Jun 2022 10:09:50 -0500
Subject: [PATCH] perf(action): Limit checked files to those changed

---
 docker/Dockerfile    | 2 +-
 docker/entrypoint.sh | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/docker/Dockerfile b/docker/Dockerfile
index 5122bc9..f94c3d3 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -1,7 +1,7 @@
 FROM ubuntu:20.04
 ARG VERSION=1.9.0
 ENV VERSION=${VERSION}
-RUN apt-get update && apt-get install -y wget
+RUN apt-get update && apt-get install -y wget git
 RUN wget https://github.com/crate-ci/typos/releases/download/v${VERSION}/typos-v${VERSION}-x86_64-unknown-linux-musl.tar.gz && \
     tar -xzvf typos-v${VERSION}-x86_64-unknown-linux-musl.tar.gz && \
     mv typos /usr/local/bin
diff --git a/docker/entrypoint.sh b/docker/entrypoint.sh
index a5e0af4..8e16d3c 100755
--- a/docker/entrypoint.sh
+++ b/docker/entrypoint.sh
@@ -8,6 +8,15 @@ log() {
 
 CMD_NAME="typos"
 TARGET=${INPUT_FILES:-"."}
+if [[ -n "${GITHUB_BASE_REF:-}" ]]; then
+    git config --global --add safe.directory /github/workspace
+    if git rev-parse --verify master 2>/dev/null ; then
+        log "Limiting checks to ${GITHUB_BASE_REF}...HEAD"
+        TARGET=$(git diff ${GITHUB_BASE_REF}...HEAD --name-only --diff-filter=AM -- ${TARGET})
+    else
+        log "WARN: Not limiting checks to ${GITHUB_BASE_REF}...HEAD, ${GITHUB_BASE_REF} is not available"
+    fi
+fi
 
 if [[ -z $(ls ${TARGET} 2>/dev/null) ]]; then
     log "ERROR: Input files (${TARGET}) not found"