Fix #1730 : Prevent binary files from being checked in using pre-commit hook

.github/workflows/static_checks.yml

@@ -107,6 +107,8 @@ jobs:
       CACHE_DIRECTORY: ~/.bazel_cache
     steps:
       - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
 
       - name: Set up Bazel
         uses: abhinavsingh/setup-bazel@v3
@@ -205,6 +207,15 @@ jobs:
         run: |
           bazel run //scripts:string_resource_validation_check -- $(pwd)
 
+      - name: Binary files check
+        # The expression if: ${{ !cancelled() }} runs a job or step regardless of its success or failure while responding to cancellations,
+        # serving as a cancellation-compliant alternative to if: ${{ always() }} in concurrent workflows.
+        if: ${{ !cancelled() }}
+        run: |
+          bash /home/runner/work/oppia-android/oppia-android/scripts/pre-commit.sh
+          echo "No binary files found in commit"
+          echo "BINARY FILES CHECK PASSED"
+
   # Note that caching is intentionally not enabled for this check since licenses should always be
   # verified without any potential influence from earlier builds (i.e. always from a clean build to
   # ensure the results exactly match the current state of the repository).

scripts/pre-commit.sh

@@ -0,0 +1,35 @@
+#!/bin/bash
+
+# Pre-commit hook to check for binary files.
+
+# Find the common ancestor between develop and the current branch
+base_commit=$(git merge-base 'origin/develop' HEAD)
+
+# Get the list of staged changes (files ready to be committed)
+staged_files=$(git diff --cached --name-only)
+
+# Get the list of changed files compared to the base commit
+changed_files=$(git diff --name-only "$base_commit" HEAD)
+
+# Combine both lists of files, ensuring no duplicates
+all_files=$(echo -e "$staged_files\n$changed_files" | sort -u)
+
+function checkForBinaries() {
+  binaryFilesCount=0
+
+  # Iterate over all files (both staged and changed)
+  for file in $all_files; do
+    if [ -f "$file" ] && file --mime "$file" | grep -q 'binary'; then
+      ((binaryFilesCount++))
+      printf "\n\033[33m%s\033[0m" "$file"
+    fi
+  done
+
+  if [[ "${binaryFilesCount}" -gt 0 ]]; then
+    printf "\n\nPlease remove the %d detected binary file(s)." "$binaryFilesCount"
+    printf "\nBINARY FILES CHECK FAILED"
+    exit 1
+  fi
+}
+
+checkForBinaries

scripts/setup.sh

@@ -13,6 +13,9 @@
 # Move file from script folder to .git/hooks folder
 cp scripts/pre-push.sh .git/hooks/pre-push
 
+# Copy the pre-commit hook from script to .git/hooks folder
+cp scripts/pre-commit.sh .git/hooks/pre-commit
+
 # Create a folder where all the set up files will be downloaded
 mkdir -p ../oppia-android-tools
 cd ../oppia-android-tools