diff --git a/Makefile b/Makefile
index 46876919..59bd181e 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@
 all: info docker test ## Run all targets.
 
 .PHONY: test
-test: info validate-container-image-labels test-lib inspec lint-codebase test-default-config-files test-actions-runner-debug test-actions-steps-debug test-runner-debug test-find lint-subset-files test-custom-ssl-cert test-non-default-workdir test-git-flags test-non-default-home-directory test-log-level test-linters-expect-failure-log-level-notice test-bash-exec-library-expect-success test-bash-exec-library-expect-failure test-linters ## Run the test suite
+test: info validate-container-image-labels test-lib inspec lint-codebase test-default-config-files test-actions-runner-debug test-actions-steps-debug test-runner-debug test-find lint-subset-files test-custom-ssl-cert test-non-default-workdir test-git-flags test-non-default-home-directory test-git-initial-commit test-log-level test-linters-expect-failure-log-level-notice test-bash-exec-library-expect-success test-bash-exec-library-expect-failure test-linters ## Run the test suite
 
 # if this session isn't interactive, then we don't want to allocate a
 # TTY, which would fail, but if it is interactive, we do want to attach
@@ -373,6 +373,12 @@ test-bash-exec-library-expect-failure: ## Run the linters test cases for BASH_EX
 		$(SUPER_LINTER_TEST_CONTAINER_URL) \
 		"run_test_case_bash_exec_library_expect_failure"
 
+.PHONY: test-git-initial-commit
+test-git-initial-commit: ## Run super-linter against a repository that only has one commit
+	$(CURDIR)/test/run-super-linter-tests.sh \
+		$(SUPER_LINTER_TEST_CONTAINER_URL) \
+		"run_test_case_git_initial_commit"
+
 .PHONY: build-dev-container-image
 build-dev-container-image: ## Build commit linter container image
 	DOCKER_BUILDKIT=1 docker buildx build --load \
diff --git a/lib/functions/buildFileList.sh b/lib/functions/buildFileList.sh
index 9363f1d3..37d2aa6e 100755
--- a/lib/functions/buildFileList.sh
+++ b/lib/functions/buildFileList.sh
@@ -16,7 +16,11 @@ function GenerateFileDiff() {
 
   if [ "${GITHUB_EVENT_NAME:-}" == "push" ]; then
     local DIFF_TREE_CMD
-    DIFF_TREE_CMD="git -C \"${GITHUB_WORKSPACE}\" diff-tree --no-commit-id --name-only -r ${GITHUB_SHA} ${GITHUB_BEFORE_SHA} | xargs -I % sh -c 'echo \"${GITHUB_WORKSPACE}/%\"' 2>&1"
+    if [[ "${GITHUB_SHA}" == "${GIT_ROOT_COMMIT_SHA}" ]]; then
+      GITHUB_BEFORE_SHA=""
+      debug "Set GITHUB_BEFORE_SHA (${GITHUB_BEFORE_SHA}) to an empty string because there's no commit before the initial commit to diff against."
+    fi
+    DIFF_TREE_CMD="git -C \"${GITHUB_WORKSPACE}\" diff-tree --no-commit-id --name-only -r --root ${GITHUB_SHA} ${GITHUB_BEFORE_SHA} | xargs -I % sh -c 'echo \"${GITHUB_WORKSPACE}/%\"' 2>&1"
     RunFileDiffCommand "${DIFF_TREE_CMD}"
     if [ ${#RAW_FILE_ARRAY[@]} -eq 0 ]; then
       debug "Generating the file array with diff-tree produced [0] items, trying with git diff against the default branch..."
diff --git a/lib/linter.sh b/lib/linter.sh
index f670c7aa..c58d270d 100755
--- a/lib/linter.sh
+++ b/lib/linter.sh
@@ -385,19 +385,26 @@ GetGitHubVars() {
     # Ensure that Git can access the local repository
     ConfigureGitSafeDirectories
 
-    if [ -z "${GITHUB_EVENT_PATH}" ]; then
+    if [ -z "${GITHUB_EVENT_PATH:-}" ]; then
       fatal "Failed to get GITHUB_EVENT_PATH: ${GITHUB_EVENT_PATH}]"
     else
       info "Successfully found GITHUB_EVENT_PATH: ${GITHUB_EVENT_PATH}]"
       debug "${GITHUB_EVENT_PATH} contents: $(cat "${GITHUB_EVENT_PATH}")"
     fi
 
-    if [ -z "${GITHUB_SHA}" ]; then
+    if [ -z "${GITHUB_SHA:-}" ]; then
       fatal "Failed to get GITHUB_SHA: ${GITHUB_SHA}"
     else
       info "Successfully found GITHUB_SHA: ${GITHUB_SHA}"
     fi
 
+    if ! GIT_ROOT_COMMIT_SHA="$(git -C "${GITHUB_WORKSPACE}" rev-list --max-parents=0 "${GITHUB_SHA}")"; then
+      fatal "Failed to get the root commit: ${GIT_ROOT_COMMIT_SHA}"
+    else
+      debug "Successfully found the root commit: ${GIT_ROOT_COMMIT_SHA}"
+    fi
+    export GIT_ROOT_COMMIT_SHA
+
     ##################################################
     # Need to pull the GitHub Vars from the env file #
     ##################################################
@@ -416,21 +423,26 @@ GetGitHubVars() {
     elif [ "${GITHUB_EVENT_NAME}" == "push" ]; then
       debug "This is a GitHub push event."
 
-      GITHUB_PUSH_COMMIT_COUNT=$(GetGithubPushEventCommitCount "$GITHUB_EVENT_PATH")
-      if [ -z "${GITHUB_PUSH_COMMIT_COUNT}" ]; then
-        fatal "Failed to get GITHUB_PUSH_COMMIT_COUNT"
-      fi
-      info "Successfully found GITHUB_PUSH_COMMIT_COUNT: ${GITHUB_PUSH_COMMIT_COUNT}"
+      if [[ "${GITHUB_SHA}" == "${GIT_ROOT_COMMIT_SHA}" ]]; then
+        debug "${GITHUB_SHA} is the initial commit. Skip initializing GITHUB_BEFORE_SHA because there no commit before the initial commit"
+      else
+        debug "${GITHUB_SHA} is not the initial commit"
+        GITHUB_PUSH_COMMIT_COUNT=$(GetGithubPushEventCommitCount "$GITHUB_EVENT_PATH")
+        if [ -z "${GITHUB_PUSH_COMMIT_COUNT}" ]; then
+          fatal "Failed to get GITHUB_PUSH_COMMIT_COUNT"
+        fi
+        info "Successfully found GITHUB_PUSH_COMMIT_COUNT: ${GITHUB_PUSH_COMMIT_COUNT}"
 
-      # Ref: https://docs.github.com/en/actions/learn-github-actions/contexts#github-context
-      debug "Get the hash of the commit to start the diff from from Git because the GitHub push event payload may not contain references to base_ref or previous commit."
-      # shellcheck disable=SC2086  # We checked that GITHUB_PUSH_COMMIT_COUNT is an integer
-      if ! GITHUB_BEFORE_SHA=$(git -C "${GITHUB_WORKSPACE}" rev-parse HEAD~${GITHUB_PUSH_COMMIT_COUNT}); then
-        fatal "Failed to initialize GITHUB_BEFORE_SHA for a push event. Output: ${GITHUB_BEFORE_SHA}"
-      fi
+        # Ref: https://docs.github.com/en/actions/learn-github-actions/contexts#github-context
+        debug "Get the hash of the commit to start the diff from from Git because the GitHub push event payload may not contain references to base_ref or previous commit."
+        # shellcheck disable=SC2086  # We checked that GITHUB_PUSH_COMMIT_COUNT is an integer
+        if ! GITHUB_BEFORE_SHA=$(git -C "${GITHUB_WORKSPACE}" rev-parse HEAD~${GITHUB_PUSH_COMMIT_COUNT}); then
+          fatal "Failed to initialize GITHUB_BEFORE_SHA for a push event. Output: ${GITHUB_BEFORE_SHA}"
+        fi
 
-      ValidateGitBeforeShaReference
-      info "Successfully found GITHUB_BEFORE_SHA: ${GITHUB_BEFORE_SHA}"
+        ValidateGitBeforeShaReference
+        info "Successfully found GITHUB_BEFORE_SHA: ${GITHUB_BEFORE_SHA}"
+      fi
     fi
 
     ############################
@@ -482,20 +494,20 @@ GetGitHubVars() {
       fatal "Cannot enable status reports when running locally."
     fi
 
-    if [ -z "${GITHUB_TOKEN}" ]; then
+    if [ -z "${GITHUB_TOKEN:-}" ]; then
       fatal "Failed to get [GITHUB_TOKEN]. Terminating because status reports were explicitly enabled, but GITHUB_TOKEN was not provided."
     else
       info "Successfully found GITHUB_TOKEN."
     fi
 
-    if [ -z "${GITHUB_REPOSITORY}" ]; then
+    if [ -z "${GITHUB_REPOSITORY:-}" ]; then
       error "Failed to get [GITHUB_REPOSITORY]!"
       fatal "[${GITHUB_REPOSITORY}]"
     else
       info "Successfully found GITHUB_REPOSITORY: ${GITHUB_REPOSITORY}"
     fi
 
-    if [ -z "${GITHUB_RUN_ID}" ]; then
+    if [ -z "${GITHUB_RUN_ID:-}" ]; then
       error "Failed to get [GITHUB_RUN_ID]!"
       fatal "[${GITHUB_RUN_ID}]"
     else
diff --git a/test/lib/buildFileListTest.sh b/test/lib/buildFileListTest.sh
index 7e08ee73..5b6e4977 100755
--- a/test/lib/buildFileListTest.sh
+++ b/test/lib/buildFileListTest.sh
@@ -32,12 +32,19 @@ git config --global user.name "Super-linter"
 
 function InitGitRepositoryAndCommitFiles() {
   local REPOSITORY_PATH="${1}" && shift
-  local FILES_TO_COMMIT="${1}"
+  local FILES_TO_COMMIT="${1}" && shift
+  local COMMIT_FILE_INITIAL_COMMIT="${1}"
 
   git -C "${REPOSITORY_PATH}" init
+  if [[ "${COMMIT_FILE_INITIAL_COMMIT}" == "true" ]]; then
+    touch "${REPOSITORY_PATH}/test-initial-commit.txt"
+    git -C "${REPOSITORY_PATH}" add .
+  fi
   git -C "${REPOSITORY_PATH}" commit --allow-empty -m "Initial commit"
   GITHUB_BEFORE_SHA=$(git -C "${REPOSITORY_PATH}" rev-parse HEAD)
   debug "GITHUB_BEFORE_SHA: ${GITHUB_BEFORE_SHA}"
+  GIT_ROOT_COMMIT_SHA="${GITHUB_BEFORE_SHA}"
+  debug "GIT_ROOT_COMMIT_SHA: ${GIT_ROOT_COMMIT_SHA}"
 
   git -C "${REPOSITORY_PATH}" checkout -b test-branch
 
@@ -56,9 +63,13 @@ function InitGitRepositoryAndCommitFiles() {
 function GenerateFileDiffOneFileTest() {
   local GITHUB_WORKSPACE
   GITHUB_WORKSPACE="$(mktemp -d)"
+  # shellcheck disable=SC2064 # Once the path is set, we don't expect it to change
+  trap "rm -fr '${GITHUB_WORKSPACE}'" EXIT
   echo "GITHUB_WORKSPACE: ${GITHUB_WORKSPACE}"
 
-  InitGitRepositoryAndCommitFiles "${GITHUB_WORKSPACE}" 1
+  local FILES_TO_COMMIT="${FILES_TO_COMMIT:-1}"
+  local COMMIT_FILE_INITIAL_COMMIT="${COMMIT_FILE_INITIAL_COMMIT:-"false"}"
+  InitGitRepositoryAndCommitFiles "${GITHUB_WORKSPACE}" "${FILES_TO_COMMIT}" "${COMMIT_FILE_INITIAL_COMMIT}"
 
   # shellcheck source=/dev/null
   source "lib/functions/buildFileList.sh"
@@ -78,16 +89,28 @@ function GenerateFileDiffOneFileTest() {
 function GenerateFileDiffOneFilePushEventTest() {
   # shellcheck disable=SC2034
   local GITHUB_EVENT_NAME="push"
+  local FILES_TO_COMMIT=1
+  local COMMIT_FILE_INITIAL_COMMIT="false"
+  GenerateFileDiffOneFileTest "${FUNCNAME[0]}"
+}
+
+function GenerateFileDiffInitialCommitPushEventTest() {
+  # shellcheck disable=SC2034
+  local GITHUB_EVENT_NAME="push"
+  local FILES_TO_COMMIT=0
+  local COMMIT_FILE_INITIAL_COMMIT="true"
   GenerateFileDiffOneFileTest "${FUNCNAME[0]}"
 }
 
 function GenerateFileDiffTwoFilesTest() {
   local GITHUB_WORKSPACE
   GITHUB_WORKSPACE="$(mktemp -d)"
+  # shellcheck disable=SC2064 # Once the path is set, we don't expect it to change
+  trap "rm -fr '${GITHUB_WORKSPACE}'" EXIT
   debug "GITHUB_WORKSPACE: ${GITHUB_WORKSPACE}"
   local FILES_TO_COMMIT=2
 
-  InitGitRepositoryAndCommitFiles "${GITHUB_WORKSPACE}" ${FILES_TO_COMMIT}
+  InitGitRepositoryAndCommitFiles "${GITHUB_WORKSPACE}" ${FILES_TO_COMMIT} "false"
 
   # shellcheck source=/dev/null
   source "lib/functions/buildFileList.sh"
@@ -114,3 +137,4 @@ GenerateFileDiffOneFileTest
 GenerateFileDiffOneFilePushEventTest
 GenerateFileDiffTwoFilesTest
 GenerateFileDiffTwoFilesPushEventTest
+GenerateFileDiffInitialCommitPushEventTest
diff --git a/test/run-super-linter-tests.sh b/test/run-super-linter-tests.sh
index 5311220d..9e59d546 100755
--- a/test/run-super-linter-tests.sh
+++ b/test/run-super-linter-tests.sh
@@ -7,14 +7,22 @@ set -o pipefail
 SUPER_LINTER_TEST_CONTAINER_URL="${1}"
 TEST_FUNCTION_NAME="${2}"
 
-COMMAND_TO_RUN=(docker run -e DEFAULT_BRANCH=main -e ENABLE_GITHUB_ACTIONS_GROUP_TITLE=true -e JSCPD_CONFIG_FILE=".jscpd-test-linters.json" -e RENOVATE_SHAREABLE_CONFIG_PRESET_FILE_NAMES="default.json,hoge.json" -e RUN_LOCAL=true -e TEST_CASE_RUN=true -e TYPESCRIPT_STANDARD_TSCONFIG_FILE=".github/linters/tsconfig.json" -v "$(pwd):/tmp/lint")
+DEFAULT_BRANCH="main"
+
+COMMAND_TO_RUN=(docker run -e DEFAULT_BRANCH="${DEFAULT_BRANCH}" -e ENABLE_GITHUB_ACTIONS_GROUP_TITLE=true)
+
+configure_linters_for_test_cases() {
+  COMMAND_TO_RUN+=(-e TEST_CASE_RUN=true -e JSCPD_CONFIG_FILE=".jscpd-test-linters.json" -e RENOVATE_SHAREABLE_CONFIG_PRESET_FILE_NAMES="default.json,hoge.json" -e TYPESCRIPT_STANDARD_TSCONFIG_FILE=".github/linters/tsconfig.json")
+}
 
 run_test_cases_expect_failure() {
+  configure_linters_for_test_cases
   COMMAND_TO_RUN+=(-e ANSIBLE_DIRECTORY="/test/linters/ansible/bad" -e CHECKOV_FILE_NAME=".checkov-test-linters-failure.yaml" -e FILTER_REGEX_INCLUDE=".*bad.*")
   EXPECTED_EXIT_CODE=1
 }
 
 run_test_cases_expect_success() {
+  configure_linters_for_test_cases
   COMMAND_TO_RUN+=(-e ANSIBLE_DIRECTORY="/test/linters/ansible/good" -e CHECKOV_FILE_NAME=".checkov-test-linters-success.yaml" -e FILTER_REGEX_INCLUDE=".*good.*")
 }
 
@@ -43,11 +51,39 @@ run_test_case_bash_exec_library_expect_success() {
   COMMAND_TO_RUN+=(-e BASH_EXEC_IGNORE_LIBRARIES="true")
 }
 
+run_test_case_git_initial_commit() {
+  local GIT_REPOSITORY_PATH
+  GIT_REPOSITORY_PATH="$(mktemp -d)"
+  # shellcheck disable=SC2064 # Once the path is set, we don't expect it to change
+  trap "rm -fr '${GIT_REPOSITORY_PATH}'" EXIT
+
+  git -C "${GIT_REPOSITORY_PATH}" init --initial-branch="${DEFAULT_BRANCH}"
+  git -C "${GIT_REPOSITORY_PATH}" config user.name "Super-linter Test"
+  git -C "${GIT_REPOSITORY_PATH}" config user.email "super-linter-test@example.com"
+  cp -v test/data/github-event/github-event-push.json "${GIT_REPOSITORY_PATH}/"
+  git -C "${GIT_REPOSITORY_PATH}" add .
+  git -C "${GIT_REPOSITORY_PATH}" commit -m "feat: initial commit"
+
+  local TEST_GITHUB_SHA
+  TEST_GITHUB_SHA="$(git -C "${GIT_REPOSITORY_PATH}" rev-parse HEAD)"
+
+  RUN_LOCAL=false
+  SUPER_LINTER_WORKSPACE="${GIT_REPOSITORY_PATH}"
+  COMMAND_TO_RUN+=(-e GITHUB_WORKSPACE="/tmp/lint")
+  COMMAND_TO_RUN+=(-e GITHUB_EVENT_NAME="push")
+  COMMAND_TO_RUN+=(-e GITHUB_EVENT_PATH="/tmp/lint/github-event-push.json")
+  COMMAND_TO_RUN+=(-e GITHUB_SHA="${TEST_GITHUB_SHA}")
+  COMMAND_TO_RUN+=(-e MULTI_STATUS=false)
+  COMMAND_TO_RUN+=(-e VALIDATE_ALL_CODEBASE=false)
+  COMMAND_TO_RUN+=(-e VALIDATE_JSON=true)
+}
+
 # Run the test setup function
 ${TEST_FUNCTION_NAME}
 
 COMMAND_TO_RUN+=(-e LOG_LEVEL="${LOG_LEVEL:-"DEBUG"}")
-
+COMMAND_TO_RUN+=(-e RUN_LOCAL="${RUN_LOCAL:-true}")
+COMMAND_TO_RUN+=(-v "${SUPER_LINTER_WORKSPACE:-$(pwd)}:/tmp/lint")
 COMMAND_TO_RUN+=("${SUPER_LINTER_TEST_CONTAINER_URL}")
 
 declare -i EXPECTED_EXIT_CODE