From e495aa826efdbe4cede399ef401ad3c6af8f6d9b Mon Sep 17 00:00:00 2001
From: Sven van Heugten <sven@memcmp.org>
Date: Wed, 4 Mar 2026 07:56:22 +0100
Subject: [PATCH 1/2] Add a failing test to show that `master` isn't supported

```git-check-assertions
run ./test/git-check-assertions.bats
assert_failure
assert_output --partial "fatal: Not a valid object name main"
```
---
 test/git-check-assertions.bats | 36 ++++++++++++++++++++++++++--------
 1 file changed, 28 insertions(+), 8 deletions(-)

diff --git a/test/git-check-assertions.bats b/test/git-check-assertions.bats
index 1755820..beb29ca 100755
--- a/test/git-check-assertions.bats
+++ b/test/git-check-assertions.bats
@@ -1,5 +1,19 @@
 #!/usr/bin/env bats
 
+init_repo() {
+  local repo_dir="$1"
+  local main_branch="$2"
+
+  mkdir "$repo_dir"
+  cd "$repo_dir"
+  git init -b "$main_branch"
+  git config user.email "john.doe@example.com"
+  git config user.name "John Doe"
+  touch readme
+  git add readme
+  git commit -m "initial"
+}
+
 setup() {
   set -euo pipefail
 
@@ -10,14 +24,7 @@ setup() {
   DIR="$(cd "$(dirname "$BATS_TEST_FILENAME")" >/dev/null 2>&1 && pwd)"
   PATH="$DIR/../bin:$PATH"
 
-  mkdir "$BATS_TEST_TMPDIR/repo"
-  cd "$BATS_TEST_TMPDIR/repo"
-  git init -b main
-  git config user.email "john.doe@example.com"
-  git config user.name "John Doe"
-  touch readme
-  git add readme
-  git commit -m "initial"
+  init_repo "$BATS_TEST_TMPDIR/repo" main
 }
 
 commit_with_assertion() {
@@ -50,6 +57,19 @@ commit_with_assertion() {
   assert_file_not_exists ../test
 }
 
+@test "should not run any assertion blocks from master when on a feature branch" {
+  init_repo "$BATS_TEST_TMPDIR/repo-master" master
+
+  commit_with_assertion "touch ../test"
+  git checkout -b feature
+  git commit --allow-empty -m "feature"
+
+  run git-check-assertions
+
+  assert_success
+  assert_file_not_exists ../test
+}
+
 @test "should run all succeeding assertion blocks on the feature branch and finally return to the original branch" {
   git checkout -b feature
   commit_with_assertion "touch ../test1"

From 9ecec1ee6deec6be5bbd3b44abb8651c5f1a7da9 Mon Sep 17 00:00:00 2001
From: Sven van Heugten <sven@memcmp.org>
Date: Wed, 4 Mar 2026 07:58:37 +0100
Subject: [PATCH 2/2] Add support for when the base branch is called `master`

```git-check-assertions
run ./test/git-check-assertions.bats
assert_success
```
---
 bin/git-check-assertions | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/bin/git-check-assertions b/bin/git-check-assertions
index 4ebc513..53fc277 100755
--- a/bin/git-check-assertions
+++ b/bin/git-check-assertions
@@ -64,7 +64,15 @@ export -f run assert_success assert_failure assert_output
 
 # main flow
 orig_ref="$(git symbolic-ref --quiet --short HEAD || git rev-parse HEAD)"
-base="$(git merge-base main HEAD)"
+if git show-ref --verify --quiet refs/heads/main; then
+  base_branch=main
+elif git show-ref --verify --quiet refs/heads/master; then
+  base_branch=master
+else
+  echo "No main or master branch found." >&2
+  exit 1
+fi
+base="$(git merge-base "$base_branch" HEAD)"
 mapfile -t commits < <(git rev-list --reverse "${base}..HEAD")
 
 echo "Base: $base"