update: handle PR branch checks

Author: namsnath

hooks/check-branch.sh

@@ -2,12 +2,12 @@
 
 source ./hooks/populate-hook-constants.sh
 
-isVersionBranch=$( if [[ ${currentBranch} =~ ^[0-9]+.[0-9]+$ ]]; then echo true; else echo false; fi )
+isVersionBranch=$( if [[ ${targetBranch} =~ ^[0-9]+.[0-9]+$ ]]; then echo true; else echo false; fi )
 
 # Check that the code version matches the branch version if on a versioned branch
 # `%.*` strips out the suffix after (and including) the last `.`
-if "$isVersionBranch" && [[ "${currentBranch%.*}" != "${newestVersion%.*}" ]]
+if "$isVersionBranch" && [[ "${targetBranch%.*}" != "${newestVersion%.*}" ]]
 then
-    echo "Code version (${newestVersion%.*}) does not match branch (${currentBranch%.*}), unexpected."
+    echo "Code version (${newestVersion%.*}) does not match branch (${targetBranch%.*}), unexpected."
     exit 1
 fi

hooks/populate-hook-constants.sh

@@ -9,5 +9,12 @@ setupVersion=$(sed -n 's/ *version *= *["]\([0-9\.]*\).*/\1/p' setup.py )
 
 newestVersion=$( if [[ "$constantsVersion" > "$setupVersion" ]]; then echo "$constantsVersion"; else echo "$setupVersion"; fi )
 
-currentBranch=$(git branch --show-current 2> /dev/null) || currentBranch="(unnamed branch)" # Get current branch
-currentBranch=${currentBranch##refs/heads/}  # Remove refs/heads/ if present
+# Target branch of the PR.
+# Ideally, this is all we want to check.
+if [[ "$GITHUB_BASE_REF" != "" ]]
+then
+    targetBranch="$GITHUB_BASE_REF"
+else # Fallback to current branch if not in a PR
+    targetBranch=$(git branch --show-current 2> /dev/null) || targetBranch="(unnamed branch)" # Get current branch
+fi
+targetBranch=${targetBranch##refs/heads/}  # Remove refs/heads/ if present