feat: add is_github_actions env helper

README.md

@@ -75,6 +75,10 @@ std::string value;
 if (lizardbyte::common::get_env("MY_ENV", value)) {
   lizardbyte::common::append_env("MY_ENV", "suffix", ";");
 }
+
+if (lizardbyte::common::is_github_actions()) {
+  // Apply GitHub Actions-specific behavior.
+}
 ```
 
 The optional test support target is available when `BUILD_TESTS=ON` or `LIZARDBYTE_COMMON_BUILD_TEST_SUPPORT=ON`.

src/common/env.cpp

@@ -17,6 +17,11 @@ namespace lizardbyte::common {
     }
   }  // namespace
 
+  bool is_github_actions() {
+    std::string value;
+    return get_env("GITHUB_ACTIONS", value);
+  }
+
   bool get_env(const std::string &name, std::string &value) {
     if (!is_valid_name(name)) {
       return false;

src/include/lizardbyte/common/env.h

@@ -8,6 +8,12 @@
 #include <string>
 
 namespace lizardbyte::common {
+  /**
+   * @brief Check whether the current process is running in GitHub Actions.
+   * @return true if the ``GITHUB_ACTIONS`` environment variable exists, false otherwise.
+   */
+  [[nodiscard]] bool is_github_actions();
+
   /**
    * @brief Get an environment variable.
    * @param name The name of the environment variable.

tests/cpp/test_env.cpp

@@ -15,6 +15,7 @@
 
 namespace {
   constexpr auto test_env_name {"LIZARDBYTE_COMMON_TEST_ENV"};
+  constexpr auto github_actions_env_name {"GITHUB_ACTIONS"};
 
   class EnvGuard {
   public:
@@ -39,6 +40,19 @@ namespace {
   };
 }  // namespace
 
+TEST(EnvTest, GitHubActionsIsFalseWhenEnvironmentVariableIsMissing) {
+  EnvGuard guard {github_actions_env_name};
+
+  EXPECT_FALSE(lizardbyte::common::is_github_actions());
+}
+
+TEST(EnvTest, GitHubActionsIsTrueWhenEnvironmentVariableExists) {
+  EnvGuard guard {github_actions_env_name};
+
+  ASSERT_EQ(lizardbyte::common::set_env(github_actions_env_name, "true"), 0);
+  EXPECT_TRUE(lizardbyte::common::is_github_actions());
+}
+
 TEST(EnvTest, GetEnvReturnsFalseForMissingVariable) {
   EnvGuard guard {test_env_name};