[PATCH 1/2] strbuf: add tests

[William Duclot <william.duclot@ensimag.grenoble-inp.fr>]

Test the strbuf API. Being used throughout all Git the API could be
considered tested, but adding specific tests makes it easier to improve
and extend the API.
---
 Makefile               |  1 +
 t/helper/test-strbuf.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++
 t/t0082-strbuf.sh      | 19 ++++++++++++++
 3 files changed, 89 insertions(+)
 create mode 100644 t/helper/test-strbuf.c
 create mode 100755 t/t0082-strbuf.sh

diff --git a/Makefile b/Makefile
index 3f03366..dc84f43 100644
--- a/Makefile
+++ b/Makefile
@@ -613,6 +613,7 @@ TEST_PROGRAMS_NEED_X += test-scrap-cache-tree
 TEST_PROGRAMS_NEED_X += test-sha1
 TEST_PROGRAMS_NEED_X += test-sha1-array
 TEST_PROGRAMS_NEED_X += test-sigchain
+TEST_PROGRAMS_NEED_X += test-strbuf
 TEST_PROGRAMS_NEED_X += test-string-list
 TEST_PROGRAMS_NEED_X += test-submodule-config
 TEST_PROGRAMS_NEED_X += test-subprocess
diff --git a/t/helper/test-strbuf.c b/t/helper/test-strbuf.c
new file mode 100644
index 0000000..622f627
--- /dev/null
+++ b/t/helper/test-strbuf.c
@@ -0,0 +1,69 @@
+#include "git-compat-util.h"
+#include "strbuf.h"
+
+/*
+ * Check behavior on usual use cases
+ */
+int test_usual(struct strbuf *sb)
+{
+	size_t size, old_alloc;
+	char *res, *old_buf, *str_test = malloc(5*sizeof(char));
+	strbuf_grow(sb, 1);
+	strcpy(str_test, "test");
+	old_alloc = sb->alloc;
+	strbuf_grow(sb, 1000);
+	if (old_alloc == sb->alloc)
+		die("strbuf_grow does not realloc the buffer as expected");
+	old_buf = sb->buf;
+	res = strbuf_detach(sb, &size);
+	if (res != old_buf)
+		die("strbuf_detach does not return the expected buffer");
+	free(res);
+
+	strcpy(str_test, "test");
+	strbuf_attach(sb, (void *)str_test, strlen(str_test), sizeof(str_test));
+	res = strbuf_detach(sb, &size);
+	if (res != str_test)
+		die("strbuf_detach does not return the expected buffer");
+	free(res);
+	strbuf_release(sb);
+
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	size_t size = 1;
+	struct strbuf sb;
+	char str_test[5] = "test";
+	char str_foo[7] = "foo";
+
+	if (argc != 2)
+		usage("test-strbuf mode");
+
+	if (!strcmp(argv[1], "basic_grow")) {
+		/*
+		 * Check if strbuf_grow(0) allocate a new NUL-terminated buffer
+		 */
+		strbuf_init(&sb, 0);
+		strbuf_grow(&sb, 0);
+		if (sb.buf == strbuf_slopbuf)
+			die("strbuf_grow failed to alloc memory");
+		strbuf_release(&sb);
+		if (sb.buf != strbuf_slopbuf)
+			die("strbuf_release does not reinitialize the strbuf");
+	} else if (!strcmp(argv[1], "strbuf_check_behavior")) {
+		strbuf_init(&sb, 0);
+		return test_usual(&sb);
+	} else if (!strcmp(argv[1], "grow_overflow")) {
+		/*
+		 * size_t overflow: should die()
+		 */
+		strbuf_init(&sb, 1000);
+		strbuf_grow(&sb, maximum_unsigned_value_of_type((size_t)1));
+	} else {
+		usage("test-strbuf mode");
+	}
+
+	return 0;
+}
diff --git a/t/t0082-strbuf.sh b/t/t0082-strbuf.sh
new file mode 100755
index 0000000..0800d26
--- /dev/null
+++ b/t/t0082-strbuf.sh
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+test_description="Test the strbuf API.
+"
+. ./test-lib.sh
+
+test_expect_success 'basic test on strbuf_grow()' '
+	test-strbuf basic_grow
+'
+
+test_expect_success 'check strbuf behavior in usual use cases ' '
+	test-strbuf strbuf_check_behavior
+'
+
+test_expect_success 'overflow while calling strbuf_grow' '
+	test_must_fail test-strbuf grow_overflow
+'
+
+test_done
-- 
2.8.2.403.ge2646ba.dirty