feat: automatically set the default branch (#5242)

Get the default branch from the GitHub Actions event payload when
running on GitHub Actions. Default to 'master', as before, otherwise.

.github/workflows/ci.yml

@@ -109,7 +109,6 @@ jobs:
           CREATE_LOG_FILE: true
           VALIDATE_ALL_CODEBASE: false
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          DEFAULT_BRANCH: main
           GITLEAKS_CONFIG_FILE: .gitleaks-ignore-tests.toml
           FILTER_REGEX_EXCLUDE: ".*(/test/linters/|CHANGELOG.md).*"
           RENOVATE_SHAREABLE_CONFIG_PRESET_FILE_NAMES: "default.json,hoge.json"
@@ -125,7 +124,6 @@ jobs:
         env:
           VALIDATE_ALL_CODEBASE: false
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          DEFAULT_BRANCH: main
           GITLEAKS_CONFIG_FILE: .gitleaks-ignore-tests.toml
           FILTER_REGEX_EXCLUDE: ".*(/test/linters/|CHANGELOG.md).*"
           TYPESCRIPT_STANDARD_TSCONFIG_FILE: ".github/linters/tsconfig.json"

README.md

@@ -113,7 +113,6 @@ To run super-linter as a GitHub Action, you do the following:
           - name: Super-linter
             uses: super-linter/super-linter@v6.0.0  # x-release-please-version
             env:
-              DEFAULT_BRANCH: main
               # To report GitHub Actions status checks
               GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     ...
@@ -167,8 +166,8 @@ You can configure super-linter using the following environment variables:
 | **CHECKOV_FILE_NAME**                           | `.checkov.yaml`                 | Configuration filename for Checkov.                                                                                                                                                                                  |
 | **CREATE_LOG_FILE**                             | `false`                         | If set to `true`, it creates the log file. You can set the log filename using the `LOG_FILE` environment variable. This overrides any existing log files.                                                            |
 | **CSS_FILE_NAME**                               | `.stylelintrc.json`             | Filename for [Stylelint configuration](https://github.com/stylelint/stylelint) (ex: `.stylelintrc.yml`, `.stylelintrc.yaml`)                                                                                         |
-| **DEFAULT_BRANCH**                              | `master`                        | The name of the repository default branch.                                                                                                                                                                           |
+| **DEFAULT_BRANCH**                              | Default repository branch when running on GitHub Actions, `master` otherwise | The name of the repository default branch. There's no need to configure this variable when running on GitHub Actions                                                    |
-| **DEFAULT_WORKSPACE**                           | `/tmp/lint`                     | The location containing files to lint if you are running locally. Defaults to `GITHUB_WORKSPACE` when running in GitHub Actions. There's no need to configure this variable when running in GitHub Actions.          |
+| **DEFAULT_WORKSPACE**                           | `/tmp/lint`                     | The location containing files to lint if you are running locally. Defaults to `GITHUB_WORKSPACE` when running in GitHub Actions. There's no need to configure this variable when running on GitHub Actions.          |
 | **DISABLE_ERRORS**                              | `false`                         | Flag to have the linter complete with exit code 0 even if errors were detected.                                                                                                                                      |
 | **DOCKERFILE_HADOLINT_FILE_NAME**               | `.hadolint.yaml`                | Filename for [hadolint configuration](https://github.com/hadolint/hadolint) (ex: `.hadolintlintrc.yaml`)                                                                                                             |
 | **EDITORCONFIG_FILE_NAME**                      | `.ecrc`                         | Filename for [editorconfig-checker configuration](https://github.com/editorconfig-checker/editorconfig-checker)                                                                                                      |

lib/functions/githubEvent.sh

@@ -16,3 +16,15 @@ function GetGithubPushEventCommitCount() {
     fatal "GITHUB_PUSH_COMMIT_COUNT is not an integer: ${GITHUB_PUSH_COMMIT_COUNT}"
   fi
 }
+
+function GetGithubRepositoryDefaultBranch() {
+  local GITHUB_EVENT_FILE_PATH
+  GITHUB_EVENT_FILE_PATH="${1}"
+  local GITHUB_REPOSITORY_DEFAULT_BRANCH
+
+  if ! GITHUB_REPOSITORY_DEFAULT_BRANCH=$(jq -r '.repository.default_branch' <"${GITHUB_EVENT_FILE_PATH}"); then
+    fatal "Failed to initialize GITHUB_REPOSITORY_DEFAULT_BRANCH. Output: ${GITHUB_REPOSITORY_DEFAULT_BRANCH}"
+  fi
+
+  echo "${GITHUB_REPOSITORY_DEFAULT_BRANCH}"
+}

lib/linter.sh

@@ -136,7 +136,6 @@ ValidateBooleanConfigurationVariables
 ###########
 # GLOBALS #
 ###########
-DEFAULT_BRANCH="${DEFAULT_BRANCH:-master}"
 DEFAULT_RULES_LOCATION='/action/lib/.automation'                            # Default rules files location
 DEFAULT_SUPER_LINTER_WORKSPACE="/tmp/lint"                                  # Fall-back value for the workspace
 DEFAULT_WORKSPACE="${DEFAULT_WORKSPACE:-${DEFAULT_SUPER_LINTER_WORKSPACE}}" # Default workspace if running locally
@@ -385,6 +384,9 @@ GetGitHubVars() {
   info "--------------------------------------------"
   info "Gathering GitHub information..."
 
+  local GITHUB_REPOSITORY_DEFAULT_BRANCH
+  GITHUB_REPOSITORY_DEFAULT_BRANCH="master"
+
   if [[ ${RUN_LOCAL} != "false" ]]; then
     info "RUN_LOCAL has been set to: ${RUN_LOCAL}. Bypassing GitHub Actions variables..."
 
@@ -487,8 +489,23 @@ GetGitHubVars() {
     else
       info "Successfully found GITHUB_REPO: ${GITHUB_REPO}"
     fi
+
+    GITHUB_REPOSITORY_DEFAULT_BRANCH=$(GetGithubRepositoryDefaultBranch "${GITHUB_EVENT_PATH}")
   fi
 
+  if [ -z "${GITHUB_REPOSITORY_DEFAULT_BRANCH}" ]; then
+    fatal "Failed to get GITHUB_REPOSITORY_DEFAULT_BRANCH"
+  else
+    debug "Successfully detected the default branch for this repository: ${GITHUB_REPOSITORY_DEFAULT_BRANCH}"
+  fi
+
+  DEFAULT_BRANCH="${DEFAULT_BRANCH:-${GITHUB_REPOSITORY_DEFAULT_BRANCH}}"
+
+  if [[ "${DEFAULT_BRANCH}" != "${GITHUB_REPOSITORY_DEFAULT_BRANCH}" ]]; then
+    debug "The default branch for this repository was set to ${GITHUB_REPOSITORY_DEFAULT_BRANCH}, but it was explicitly overridden using the DEFAULT_BRANCH variable, and set to: ${DEFAULT_BRANCH}"
+  fi
+  info "The default branch for this repository is set to: ${DEFAULT_BRANCH}"
+
   if [ "${MULTI_STATUS}" == "true" ]; then
 
     if [[ ${RUN_LOCAL} == "true" ]]; then

test/lib/githubEventTest.sh

@@ -43,3 +43,22 @@ function GetGithubPushEventCommitCountTest() {
 }
 
 GetGithubPushEventCommitCountTest
+
+function GetGithubRepositoryDefaultBranchTest() {
+  local GITHUB_REPOSITORY_DEFAULT_BRANCH
+  GITHUB_REPOSITORY_DEFAULT_BRANCH=$(GetGithubRepositoryDefaultBranch "test/data/github-event/github-event-push.json")
+
+  debug "GITHUB_REPOSITORY_DEFAULT_BRANCH: ${GITHUB_REPOSITORY_DEFAULT_BRANCH}"
+
+  local EXPECTED_GITHUB_REPOSITORY_DEFAULT_BRANCH
+  EXPECTED_GITHUB_REPOSITORY_DEFAULT_BRANCH="main"
+
+  if [ "${GITHUB_REPOSITORY_DEFAULT_BRANCH}" != "${EXPECTED_GITHUB_REPOSITORY_DEFAULT_BRANCH}" ]; then
+    fatal "GITHUB_REPOSITORY_DEFAULT_BRANCH (${GITHUB_REPOSITORY_DEFAULT_BRANCH}) is not equal to: ${EXPECTED_GITHUB_REPOSITORY_DEFAULT_BRANCH}"
+  fi
+
+  FUNCTION_NAME="${FUNCNAME[0]}"
+  notice "${FUNCTION_NAME} PASS"
+}
+
+GetGithubRepositoryDefaultBranchTest