util: introduce memstream-util

There is many pitfalls in using memstream.
Let's introduce a wrapper to make us safely use it.

1 files changed, 60 insertions, 0 deletions

diff --git a/src/test/test-memstream-util.c b/src/test/test-memstream-util.c
new file mode 100644
index 0000000000..254bdcaa15
--- /dev/null
+++ b/src/test/test-memstream-util.c
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "memstream-util.h"
+#include "string-util.h"
+#include "tests.h"
+
+TEST(memstream_done) {
+        _cleanup_(memstream_done) MemStream m = {};
+
+        assert_se(memstream_init(&m));
+}
+
+TEST(memstream_empty) {
+        _cleanup_(memstream_done) MemStream m = {};
+        _cleanup_free_ char *buf = NULL;
+        size_t sz;
+
+        assert_se(memstream_init(&m));
+        assert_se(memstream_finalize(&m, &buf, &sz) >= 0);
+        assert_se(streq(buf, ""));
+        assert_se(sz == 0);
+}
+
+TEST(memstream) {
+        _cleanup_(memstream_done) MemStream m = {};
+        _cleanup_free_ char *buf = NULL;
+        size_t sz;
+        FILE *f;
+
+        assert_se(f = memstream_init(&m));
+        fputs("hoge", f);
+        fputs("おはよう！", f);
+        fputs(u8"😀😀😀", f);
+        assert_se(memstream_finalize(&m, &buf, &sz) >= 0);
+        assert_se(streq(buf, u8"hogeおはよう！😀😀😀"));
+        assert_se(sz == strlen(u8"hogeおはよう！😀😀😀"));
+
+        buf = mfree(buf);
+
+        assert_se(f = memstream_init(&m));
+        fputs("second", f);
+        assert_se(memstream_finalize(&m, &buf, &sz) >= 0);
+        assert_se(streq(buf, "second"));
+        assert_se(sz == strlen("second"));
+}
+
+TEST(memstream_dump) {
+        _cleanup_(memstream_done) MemStream m = {};
+        FILE *f;
+
+        assert_se(f = memstream_init(&m));
+        fputs("first", f);
+        assert_se(memstream_dump(LOG_DEBUG, &m) >= 0);
+
+        assert_se(f = memstream_init(&m));
+        fputs("second", f);
+        assert_se(memstream_dump(LOG_DEBUG, &m) >= 0);
+}
+
+DEFINE_TEST_MAIN(LOG_DEBUG);