From 48f049e33cb34dac78fdcfdda79d9fd56bbaffa6 Mon Sep 17 00:00:00 2001
From: Joel Rosdahl <joel@rosdahl.net>
Date: Tue, 8 Sep 2020 20:05:43 +0200
Subject: [PATCH] Add Util::ensure_dir_exists

---
 src/Util.cpp           |  8 ++++++++
 src/Util.hpp           |  3 +++
 unittest/test_Util.cpp | 15 +++++++++++++++
 3 files changed, 26 insertions(+)

diff --git a/src/Util.cpp b/src/Util.cpp
index 644864b9d..78e3d8445 100644
--- a/src/Util.cpp
+++ b/src/Util.cpp
@@ -556,6 +556,14 @@ format_parsable_size_with_suffix(uint64_t size)
   }
 }
 
+void
+ensure_dir_exists(nonstd::string_view dir)
+{
+  if (!create_dir(dir)) {
+    throw Fatal("Failed to create directory {}: {}", dir, strerror(errno));
+  }
+}
+
 std::string
 get_actual_cwd()
 {
diff --git a/src/Util.hpp b/src/Util.hpp
index c00078031..834f9f74e 100644
--- a/src/Util.hpp
+++ b/src/Util.hpp
@@ -124,6 +124,9 @@ ends_with(nonstd::string_view string, nonstd::string_view suffix)
   return string.ends_with(suffix);
 }
 
+// Like create_dir but throws Fatal on error.
+void ensure_dir_exists(nonstd::string_view dir);
+
 // Expand all instances of $VAR or ${VAR}, where VAR is an environment variable,
 // in `str`. Throws `Error` if one of the environment variables.
 [[nodiscard]] std::string expand_environment_variables(const std::string& str);
diff --git a/unittest/test_Util.cpp b/unittest/test_Util.cpp
index 077a8660a..154ab509e 100644
--- a/unittest/test_Util.cpp
+++ b/unittest/test_Util.cpp
@@ -163,6 +163,21 @@ TEST_CASE("Util::ends_with")
   CHECK_FALSE(Util::ends_with("x", "xy"));
 }
 
+TEST_CASE("Util::ensure_dir_exists")
+{
+  TestContext test_context;
+
+  CHECK_NOTHROW(Util::ensure_dir_exists("/"));
+
+  CHECK_NOTHROW(Util::ensure_dir_exists("create/dir"));
+  CHECK(Stat::stat("create/dir").is_directory());
+
+  Util::write_file("create/dir/file", "");
+  CHECK_THROWS_WITH(
+    Util::ensure_dir_exists("create/dir/file"),
+    "Failed to create directory create/dir/file: Not a directory");
+}
+
 TEST_CASE("Util::expand_environment_variables")
 {
   Util::setenv("FOO", "bar");
-- 
2.47.3