6 files changed, 1322 insertions, 356 deletions
diff --git a/t/unit-tests/t-ctype.c b/t/unit-tests/t-ctype.c
index 24cc566cfe..6043f0d9bc 100644
--- a/t/unit-tests/t-ctype.c
+++ b/t/unit-tests/t-ctype.c
@@ -4,15 +4,13 @@
 	size_t len = ARRAY_SIZE(string) - 1 + \
 		BUILD_ASSERT_OR_ZERO(ARRAY_SIZE(string) > 0) + \
 		BUILD_ASSERT_OR_ZERO(sizeof(string[0]) == sizeof(char)); \
-	int skip = test__run_begin(); \
-	if (!skip) { \
+	if_test (#class " works") { \
 		for (int i = 0; i < 256; i++) { \
 			if (!check_int(class(i), ==, !!memchr(string, i, len)))\
 				test_msg("      i: 0x%02x", i); \
 		} \
 		check(!class(EOF)); \
 	} \
-	test__run_end(!skip, TEST_LOCATION(), #class " works"); \
 } while (0)
 
 #define DIGIT "0123456789"
diff --git a/t/unit-tests/t-reftable-basics.c b/t/unit-tests/t-reftable-basics.c
index 7ffee74dca..e5556ebf52 100644
--- a/t/unit-tests/t-reftable-basics.c
+++ b/t/unit-tests/t-reftable-basics.c
@@ -20,141 +20,125 @@ static int integer_needle_lesseq(size_t i, void *_args)
 	return args->needle <= args->haystack[i];
 }
 
-static void test_binsearch(void)
+int cmd_main(int argc UNUSED, const char *argv[] UNUSED)
 {
-	int haystack[] = { 2, 4, 6, 8, 10 };
-	struct {
-		int needle;
-		size_t expected_idx;
-	} testcases[] = {
-		{-9000, 0},
-		{-1, 0},
-		{0, 0},
-		{2, 0},
-		{3, 1},
-		{4, 1},
-		{7, 3},
-		{9, 4},
-		{10, 4},
-		{11, 5},
-		{9000, 5},
-	};
-
-	for (size_t i = 0; i < ARRAY_SIZE(testcases); i++) {
-		struct integer_needle_lesseq_args args = {
-			.haystack = haystack,
-			.needle = testcases[i].needle,
+	if_test ("binary search with binsearch works") {
+		int haystack[] = { 2, 4, 6, 8, 10 };
+		struct {
+			int needle;
+			size_t expected_idx;
+		} testcases[] = {
+			{-9000, 0},
+			{-1, 0},
+			{0, 0},
+			{2, 0},
+			{3, 1},
+			{4, 1},
+			{7, 3},
+			{9, 4},
+			{10, 4},
+			{11, 5},
+			{9000, 5},
 		};
-		size_t idx;
 
-		idx = binsearch(ARRAY_SIZE(haystack), &integer_needle_lesseq, &args);
-		check_int(idx, ==, testcases[i].expected_idx);
+		for (size_t i = 0; i < ARRAY_SIZE(testcases); i++) {
+			struct integer_needle_lesseq_args args = {
+				.haystack = haystack,
+				.needle = testcases[i].needle,
+			};
+			size_t idx;
+
+			idx = binsearch(ARRAY_SIZE(haystack),
+					&integer_needle_lesseq, &args);
+			check_int(idx, ==, testcases[i].expected_idx);
+		}
 	}
-}
 
-static void test_names_length(void)
-{
-	const char *a[] = { "a", "b", NULL };
-	check_int(names_length(a), ==, 2);
-}
-
-static void test_names_equal(void)
-{
-	const char *a[] = { "a", "b", "c", NULL };
-	const char *b[] = { "a", "b", "d", NULL };
-	const char *c[] = { "a", "b", NULL };
+	if_test ("names_length retuns size of a NULL-terminated string array") {
+		const char *a[] = { "a", "b", NULL };
+		check_int(names_length(a), ==, 2);
+	}
 
-	check(names_equal(a, a));
-	check(!names_equal(a, b));
-	check(!names_equal(a, c));
-}
+	if_test ("names_equal compares NULL-terminated string arrays") {
+		const char *a[] = { "a", "b", "c", NULL };
+		const char *b[] = { "a", "b", "d", NULL };
+		const char *c[] = { "a", "b", NULL };
 
-static void test_parse_names_normal(void)
-{
-	char in1[] = "line\n";
-	char in2[] = "a\nb\nc";
-	char **out = NULL;
-	parse_names(in1, strlen(in1), &out);
-	check_str(out[0], "line");
-	check(!out[1]);
-	free_names(out);
-
-	parse_names(in2, strlen(in2), &out);
-	check_str(out[0], "a");
-	check_str(out[1], "b");
-	check_str(out[2], "c");
-	check(!out[3]);
-	free_names(out);
-}
+		check(names_equal(a, a));
+		check(!names_equal(a, b));
+		check(!names_equal(a, c));
+	}
 
-static void test_parse_names_drop_empty(void)
-{
-	char in[] = "a\n\nb\n";
-	char **out = NULL;
-	parse_names(in, strlen(in), &out);
-	check_str(out[0], "a");
-	/* simply '\n' should be dropped as empty string */
-	check_str(out[1], "b");
-	check(!out[2]);
-	free_names(out);
-}
+	if_test ("parse_names works for basic input") {
+		char in1[] = "line\n";
+		char in2[] = "a\nb\nc";
+		char **out = NULL;
+		parse_names(in1, strlen(in1), &out);
+		check_str(out[0], "line");
+		check(!out[1]);
+		free_names(out);
+
+		parse_names(in2, strlen(in2), &out);
+		check_str(out[0], "a");
+		check_str(out[1], "b");
+		check_str(out[2], "c");
+		check(!out[3]);
+		free_names(out);
+	}
 
-static void test_common_prefix(void)
-{
-	struct strbuf a = STRBUF_INIT;
-	struct strbuf b = STRBUF_INIT;
-	struct {
-		const char *a, *b;
-		int want;
-	} cases[] = {
-		{"abcdef", "abc", 3},
-		{ "abc", "ab", 2 },
-		{ "", "abc", 0 },
-		{ "abc", "abd", 2 },
-		{ "abc", "pqr", 0 },
-	};
-
-	for (size_t i = 0; i < ARRAY_SIZE(cases); i++) {
-		strbuf_addstr(&a, cases[i].a);
-		strbuf_addstr(&b, cases[i].b);
-		check_int(common_prefix_size(&a, &b), ==, cases[i].want);
-		strbuf_reset(&a);
-		strbuf_reset(&b);
+	if_test ("parse_names drops empty string") {
+		char in[] = "a\n\nb\n";
+		char **out = NULL;
+		parse_names(in, strlen(in), &out);
+		check_str(out[0], "a");
+		/* simply '\n' should be dropped as empty string */
+		check_str(out[1], "b");
+		check(!out[2]);
+		free_names(out);
 	}
-	strbuf_release(&a);
-	strbuf_release(&b);
-}
 
-static void test_u24_roundtrip(void)
-{
-	uint32_t in = 0x112233;
-	uint8_t dest[3];
-	uint32_t out;
-	put_be24(dest, in);
-	out = get_be24(dest);
-	check_int(in, ==, out);
-}
+	if_test ("common_prefix_size works") {
+		struct strbuf a = STRBUF_INIT;
+		struct strbuf b = STRBUF_INIT;
+		struct {
+			const char *a, *b;
+			int want;
+		} cases[] = {
+			{"abcdef", "abc", 3},
+			{ "abc", "ab", 2 },
+			{ "", "abc", 0 },
+			{ "abc", "abd", 2 },
+			{ "abc", "pqr", 0 },
+		};
 
-static void test_u16_roundtrip(void)
-{
-	uint32_t in = 0xfef1;
-	uint8_t dest[3];
-	uint32_t out;
-	put_be16(dest, in);
-	out = get_be16(dest);
-	check_int(in, ==, out);
-}
+		for (size_t i = 0; i < ARRAY_SIZE(cases); i++) {
+			strbuf_addstr(&a, cases[i].a);
+			strbuf_addstr(&b, cases[i].b);
+			check_int(common_prefix_size(&a, &b), ==, cases[i].want);
+			strbuf_reset(&a);
+			strbuf_reset(&b);
+		}
+		strbuf_release(&a);
+		strbuf_release(&b);
+	}
 
-int cmd_main(int argc UNUSED, const char *argv[] UNUSED)
-{
-	TEST(test_common_prefix(), "common_prefix_size works");
-	TEST(test_parse_names_normal(), "parse_names works for basic input");
-	TEST(test_parse_names_drop_empty(), "parse_names drops empty string");
-	TEST(test_binsearch(), "binary search with binsearch works");
-	TEST(test_names_length(), "names_length retuns size of a NULL-terminated string array");
-	TEST(test_names_equal(), "names_equal compares NULL-terminated string arrays");
-	TEST(test_u24_roundtrip(), "put_be24 and get_be24 work");
-	TEST(test_u16_roundtrip(), "put_be16 and get_be16 work");
+	if_test ("put_be24 and get_be24 work") {
+		uint32_t in = 0x112233;
+		uint8_t dest[3];
+		uint32_t out;
+		put_be24(dest, in);
+		out = get_be24(dest);
+		check_int(in, ==, out);
+	}
+
+	if_test ("put_be16 and get_be16 work") {
+		uint32_t in = 0xfef1;
+		uint8_t dest[3];
+		uint32_t out;
+		put_be16(dest, in);
+		out = get_be16(dest);
+		check_int(in, ==, out);
+	}
 
 	return test_done();
 }
diff --git a/t/unit-tests/t-reftable-readwrite.c b/t/unit-tests/t-reftable-readwrite.c
new file mode 100644
index 0000000000..1eae36cc60
--- /dev/null
+++ b/t/unit-tests/t-reftable-readwrite.c
@@ -0,0 +1,974 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "test-lib.h"
+#include "reftable/basics.h"
+#include "reftable/blocksource.h"
+#include "reftable/reader.h"
+#include "reftable/reftable-error.h"
+#include "reftable/reftable-writer.h"
+
+static const int update_index = 5;
+
+static void set_test_hash(uint8_t *p, int i)
+{
+	memset(p, (uint8_t)i, hash_size(GIT_SHA1_FORMAT_ID));
+}
+
+static ssize_t strbuf_add_void(void *b, const void *data, size_t sz)
+{
+	strbuf_add(b, data, sz);
+	return sz;
+}
+
+static int noop_flush(void *arg)
+{
+	return 0;
+}
+
+static void t_buffer(void)
+{
+	struct strbuf buf = STRBUF_INIT;
+	struct reftable_block_source source = { 0 };
+	struct reftable_block out = { 0 };
+	int n;
+	uint8_t in[] = "hello";
+	strbuf_add(&buf, in, sizeof(in));
+	block_source_from_strbuf(&source, &buf);
+	check_int(block_source_size(&source), ==, 6);
+	n = block_source_read_block(&source, &out, 0, sizeof(in));
+	check_int(n, ==, sizeof(in));
+	check(!memcmp(in, out.data, n));
+	reftable_block_done(&out);
+
+	n = block_source_read_block(&source, &out, 1, 2);
+	check_int(n, ==, 2);
+	check(!memcmp(out.data, "el", 2));
+
+	reftable_block_done(&out);
+	block_source_close(&source);
+	strbuf_release(&buf);
+}
+
+static void write_table(char ***names, struct strbuf *buf, int N,
+			int block_size, uint32_t hash_id)
+{
+	struct reftable_write_options opts = {
+		.block_size = block_size,
+		.hash_id = hash_id,
+	};
+	struct reftable_writer *w =
+		reftable_new_writer(&strbuf_add_void, &noop_flush, buf, &opts);
+	struct reftable_ref_record ref = { 0 };
+	int i = 0, n;
+	struct reftable_log_record log = { 0 };
+	const struct reftable_stats *stats = NULL;
+
+	REFTABLE_CALLOC_ARRAY(*names, N + 1);
+
+	reftable_writer_set_limits(w, update_index, update_index);
+	for (i = 0; i < N; i++) {
+		char name[100];
+		int n;
+
+		snprintf(name, sizeof(name), "refs/heads/branch%02d", i);
+
+		ref.refname = name;
+		ref.update_index = update_index;
+		ref.value_type = REFTABLE_REF_VAL1;
+		set_test_hash(ref.value.val1, i);
+		(*names)[i] = xstrdup(name);
+
+		n = reftable_writer_add_ref(w, &ref);
+		check_int(n, ==, 0);
+	}
+
+	for (i = 0; i < N; i++) {
+		char name[100];
+		int n;
+
+		snprintf(name, sizeof(name), "refs/heads/branch%02d", i);
+
+		log.refname = name;
+		log.update_index = update_index;
+		log.value_type = REFTABLE_LOG_UPDATE;
+		set_test_hash(log.value.update.new_hash, i);
+		log.value.update.message = (char *) "message";
+
+		n = reftable_writer_add_log(w, &log);
+		check_int(n, ==, 0);
+	}
+
+	n = reftable_writer_close(w);
+	check_int(n, ==, 0);
+
+	stats = reftable_writer_stats(w);
+	for (i = 0; i < stats->ref_stats.blocks; i++) {
+		int off = i * opts.block_size;
+		if (!off)
+			off = header_size((hash_id == GIT_SHA256_FORMAT_ID) ? 2 : 1);
+		check_char(buf->buf[off], ==, 'r');
+	}
+
+	check_int(stats->log_stats.blocks, >, 0);
+	reftable_writer_free(w);
+}
+
+static void t_log_buffer_size(void)
+{
+	struct strbuf buf = STRBUF_INIT;
+	struct reftable_write_options opts = {
+		.block_size = 4096,
+	};
+	int err;
+	int i;
+	struct reftable_log_record
+		log = { .refname = (char *) "refs/heads/master",
+			.update_index = 0xa,
+			.value_type = REFTABLE_LOG_UPDATE,
+			.value = { .update = {
+					   .name = (char *) "Han-Wen Nienhuys",
+					   .email = (char *) "hanwen@google.com",
+					   .tz_offset = 100,
+					   .time = 0x5e430672,
+					   .message = (char *) "commit: 9\n",
+				   } } };
+	struct reftable_writer *w =
+		reftable_new_writer(&strbuf_add_void, &noop_flush, &buf, &opts);
+
+	/* This tests buffer extension for log compression. Must use a random
+	   hash, to ensure that the compressed part is larger than the original.
+	*/
+	for (i = 0; i < GIT_SHA1_RAWSZ; i++) {
+		log.value.update.old_hash[i] = (uint8_t)(git_rand() % 256);
+		log.value.update.new_hash[i] = (uint8_t)(git_rand() % 256);
+	}
+	reftable_writer_set_limits(w, update_index, update_index);
+	err = reftable_writer_add_log(w, &log);
+	check(!err);
+	err = reftable_writer_close(w);
+	check(!err);
+	reftable_writer_free(w);
+	strbuf_release(&buf);
+}
+
+static void t_log_overflow(void)
+{
+	struct strbuf buf = STRBUF_INIT;
+	char msg[256] = { 0 };
+	struct reftable_write_options opts = {
+		.block_size = ARRAY_SIZE(msg),
+	};
+	int err;
+	struct reftable_log_record log = {
+		.refname = (char *) "refs/heads/master",
+		.update_index = 0xa,
+		.value_type = REFTABLE_LOG_UPDATE,
+		.value = {
+			.update = {
+				.old_hash = { 1 },
+				.new_hash = { 2 },
+				.name = (char *) "Han-Wen Nienhuys",
+				.email = (char *) "hanwen@google.com",
+				.tz_offset = 100,
+				.time = 0x5e430672,
+				.message = msg,
+			},
+		},
+	};
+	struct reftable_writer *w =
+		reftable_new_writer(&strbuf_add_void, &noop_flush, &buf, &opts);
+
+	memset(msg, 'x', sizeof(msg) - 1);
+	reftable_writer_set_limits(w, update_index, update_index);
+	err = reftable_writer_add_log(w, &log);
+	check_int(err, ==, REFTABLE_ENTRY_TOO_BIG_ERROR);
+	reftable_writer_free(w);
+	strbuf_release(&buf);
+}
+
+static void t_log_write_read(void)
+{
+	int N = 2;
+	char **names = reftable_calloc(N + 1, sizeof(*names));
+	int err;
+	struct reftable_write_options opts = {
+		.block_size = 256,
+	};
+	struct reftable_ref_record ref = { 0 };
+	int i = 0;
+	struct reftable_log_record log = { 0 };
+	int n;
+	struct reftable_iterator it = { 0 };
+	struct reftable_reader rd = { 0 };
+	struct reftable_block_source source = { 0 };
+	struct strbuf buf = STRBUF_INIT;
+	struct reftable_writer *w =
+		reftable_new_writer(&strbuf_add_void, &noop_flush, &buf, &opts);
+	const struct reftable_stats *stats = NULL;
+	reftable_writer_set_limits(w, 0, N);
+	for (i = 0; i < N; i++) {
+		char name[256];
+		struct reftable_ref_record ref = { 0 };
+		snprintf(name, sizeof(name), "b%02d%0*d", i, 130, 7);
+		names[i] = xstrdup(name);
+		ref.refname = name;
+		ref.update_index = i;
+
+		err = reftable_writer_add_ref(w, &ref);
+		check(!err);
+	}
+	for (i = 0; i < N; i++) {
+		struct reftable_log_record log = { 0 };
+
+		log.refname = names[i];
+		log.update_index = i;
+		log.value_type = REFTABLE_LOG_UPDATE;
+		set_test_hash(log.value.update.old_hash, i);
+		set_test_hash(log.value.update.new_hash, i + 1);
+
+		err = reftable_writer_add_log(w, &log);
+		check(!err);
+	}
+
+	n = reftable_writer_close(w);
+	check_int(n, ==, 0);
+
+	stats = reftable_writer_stats(w);
+	check_int(stats->log_stats.blocks, >, 0);
+	reftable_writer_free(w);
+	w = NULL;
+
+	block_source_from_strbuf(&source, &buf);
+
+	err = init_reader(&rd, &source, "file.log");
+	check(!err);
+
+	reftable_reader_init_ref_iterator(&rd, &it);
+
+	err = reftable_iterator_seek_ref(&it, names[N - 1]);
+	check(!err);
+
+	err = reftable_iterator_next_ref(&it, &ref);
+	check(!err);
+
+	/* end of iteration. */
+	err = reftable_iterator_next_ref(&it, &ref);
+	check_int(err, >, 0);
+
+	reftable_iterator_destroy(&it);
+	reftable_ref_record_release(&ref);
+
+	reftable_reader_init_log_iterator(&rd, &it);
+
+	err = reftable_iterator_seek_log(&it, "");
+	check(!err);
+
+	for (i = 0; ; i++) {
+		int err = reftable_iterator_next_log(&it, &log);
+		if (err > 0)
+			break;
+		check(!err);
+		check_str(names[i], log.refname);
+		check_int(i, ==, log.update_index);
+		reftable_log_record_release(&log);
+	}
+
+	check_int(i, ==, N);
+	reftable_iterator_destroy(&it);
+
+	/* cleanup. */
+	strbuf_release(&buf);
+	free_names(names);
+	reader_close(&rd);
+}
+
+static void t_log_zlib_corruption(void)
+{
+	struct reftable_write_options opts = {
+		.block_size = 256,
+	};
+	struct reftable_iterator it = { 0 };
+	struct reftable_reader rd = { 0 };
+	struct reftable_block_source source = { 0 };
+	struct strbuf buf = STRBUF_INIT;
+	struct reftable_writer *w =
+		reftable_new_writer(&strbuf_add_void, &noop_flush, &buf, &opts);
+	const struct reftable_stats *stats = NULL;
+	char message[100] = { 0 };
+	int err, i, n;
+	struct reftable_log_record log = {
+		.refname = (char *) "refname",
+		.value_type = REFTABLE_LOG_UPDATE,
+		.value = {
+			.update = {
+				.new_hash = { 1 },
+				.old_hash = { 2 },
+				.name = (char *) "My Name",
+				.email = (char *) "myname@invalid",
+				.message = message,
+			},
+		},
+	};
+
+	for (i = 0; i < sizeof(message) - 1; i++)
+		message[i] = (uint8_t)(git_rand() % 64 + ' ');
+
+	reftable_writer_set_limits(w, 1, 1);
+
+	err = reftable_writer_add_log(w, &log);
+	check(!err);
+
+	n = reftable_writer_close(w);
+	check_int(n, ==, 0);
+
+	stats = reftable_writer_stats(w);
+	check_int(stats->log_stats.blocks, >, 0);
+	reftable_writer_free(w);
+	w = NULL;
+
+	/* corrupt the data. */
+	buf.buf[50] ^= 0x99;
+
+	block_source_from_strbuf(&source, &buf);
+
+	err = init_reader(&rd, &source, "file.log");
+	check(!err);
+
+	reftable_reader_init_log_iterator(&rd, &it);
+	err = reftable_iterator_seek_log(&it, "refname");
+	check_int(err, ==, REFTABLE_ZLIB_ERROR);
+
+	reftable_iterator_destroy(&it);
+
+	/* cleanup. */
+	strbuf_release(&buf);
+	reader_close(&rd);
+}
+
+static void t_table_read_write_sequential(void)
+{
+	char **names;
+	struct strbuf buf = STRBUF_INIT;
+	int N = 50;
+	struct reftable_iterator it = { 0 };
+	struct reftable_block_source source = { 0 };
+	struct reftable_reader rd = { 0 };
+	int err = 0;
+	int j = 0;
+
+	write_table(&names, &buf, N, 256, GIT_SHA1_FORMAT_ID);
+
+	block_source_from_strbuf(&source, &buf);
+
+	err = init_reader(&rd, &source, "file.ref");
+	check(!err);
+
+	reftable_reader_init_ref_iterator(&rd, &it);
+	err = reftable_iterator_seek_ref(&it, "");
+	check(!err);
+
+	for (j = 0; ; j++) {
+		struct reftable_ref_record ref = { 0 };
+		int r = reftable_iterator_next_ref(&it, &ref);
+		check_int(r, >=, 0);
+		if (r > 0)
+			break;
+		check_str(names[j], ref.refname);
+		check_int(update_index, ==, ref.update_index);
+		reftable_ref_record_release(&ref);
+	}
+	check_int(j, ==, N);
+	reftable_iterator_destroy(&it);
+	strbuf_release(&buf);
+	free_names(names);
+
+	reader_close(&rd);
+}
+
+static void t_table_write_small_table(void)
+{
+	char **names;
+	struct strbuf buf = STRBUF_INIT;
+	int N = 1;
+	write_table(&names, &buf, N, 4096, GIT_SHA1_FORMAT_ID);
+	check_int(buf.len, <, 200);
+	strbuf_release(&buf);
+	free_names(names);
+}
+
+static void t_table_read_api(void)
+{
+	char **names;
+	struct strbuf buf = STRBUF_INIT;
+	int N = 50;
+	struct reftable_reader rd = { 0 };
+	struct reftable_block_source source = { 0 };
+	int err;
+	struct reftable_log_record log = { 0 };
+	struct reftable_iterator it = { 0 };
+
+	write_table(&names, &buf, N, 256, GIT_SHA1_FORMAT_ID);
+
+	block_source_from_strbuf(&source, &buf);
+
+	err = init_reader(&rd, &source, "file.ref");
+	check(!err);
+
+	reftable_reader_init_ref_iterator(&rd, &it);
+	err = reftable_iterator_seek_ref(&it, names[0]);
+	check(!err);
+
+	err = reftable_iterator_next_log(&it, &log);
+	check_int(err, ==, REFTABLE_API_ERROR);
+
+	strbuf_release(&buf);
+	free_names(names);
+	reftable_iterator_destroy(&it);
+	reader_close(&rd);
+	strbuf_release(&buf);
+}
+
+static void t_table_read_write_seek(int index, int hash_id)
+{
+	char **names;
+	struct strbuf buf = STRBUF_INIT;
+	int N = 50;
+	struct reftable_reader rd = { 0 };
+	struct reftable_block_source source = { 0 };
+	int err;
+	int i = 0;
+
+	struct reftable_iterator it = { 0 };
+	struct strbuf pastLast = STRBUF_INIT;
+	struct reftable_ref_record ref = { 0 };
+
+	write_table(&names, &buf, N, 256, hash_id);
+
+	block_source_from_strbuf(&source, &buf);
+
+	err = init_reader(&rd, &source, "file.ref");
+	check(!err);
+	check_int(hash_id, ==, reftable_reader_hash_id(&rd));
+
+	if (!index)
+		rd.ref_offsets.index_offset = 0;
+	else
+		check_int(rd.ref_offsets.index_offset, >, 0);
+
+	for (i = 1; i < N; i++) {
+		reftable_reader_init_ref_iterator(&rd, &it);
+		err = reftable_iterator_seek_ref(&it, names[i]);
+		check(!err);
+		err = reftable_iterator_next_ref(&it, &ref);
+		check(!err);
+		check_str(names[i], ref.refname);
+		check_int(REFTABLE_REF_VAL1, ==, ref.value_type);
+		check_int(i, ==, ref.value.val1[0]);
+
+		reftable_ref_record_release(&ref);
+		reftable_iterator_destroy(&it);
+	}
+
+	strbuf_addstr(&pastLast, names[N - 1]);
+	strbuf_addstr(&pastLast, "/");
+
+	reftable_reader_init_ref_iterator(&rd, &it);
+	err = reftable_iterator_seek_ref(&it, pastLast.buf);
+	if (err == 0) {
+		struct reftable_ref_record ref = { 0 };
+		int err = reftable_iterator_next_ref(&it, &ref);
+		check_int(err, >, 0);
+	} else {
+		check_int(err, >, 0);
+	}
+
+	strbuf_release(&pastLast);
+	reftable_iterator_destroy(&it);
+
+	strbuf_release(&buf);
+	free_names(names);
+	reader_close(&rd);
+}
+
+static void t_table_read_write_seek_linear(void)
+{
+	t_table_read_write_seek(0, GIT_SHA1_FORMAT_ID);
+}
+
+static void t_table_read_write_seek_linear_sha256(void)
+{
+	t_table_read_write_seek(0, GIT_SHA256_FORMAT_ID);
+}
+
+static void t_table_read_write_seek_index(void)
+{
+	t_table_read_write_seek(1, GIT_SHA1_FORMAT_ID);
+}
+
+static void t_table_refs_for(int indexed)
+{
+	int N = 50;
+	char **want_names = reftable_calloc(N + 1, sizeof(*want_names));
+	int want_names_len = 0;
+	uint8_t want_hash[GIT_SHA1_RAWSZ];
+
+	struct reftable_write_options opts = {
+		.block_size = 256,
+	};
+	struct reftable_ref_record ref = { 0 };
+	int i = 0;
+	int n;
+	int err;
+	struct reftable_reader rd;
+	struct reftable_block_source source = { 0 };
+
+	struct strbuf buf = STRBUF_INIT;
+	struct reftable_writer *w =
+		reftable_new_writer(&strbuf_add_void, &noop_flush, &buf, &opts);
+
+	struct reftable_iterator it = { 0 };
+	int j;
+
+	set_test_hash(want_hash, 4);
+
+	for (i = 0; i < N; i++) {
+		uint8_t hash[GIT_SHA1_RAWSZ];
+		char fill[51] = { 0 };
+		char name[100];
+		struct reftable_ref_record ref = { 0 };
+
+		memset(hash, i, sizeof(hash));
+		memset(fill, 'x', 50);
+		/* Put the variable part in the start */
+		snprintf(name, sizeof(name), "br%02d%s", i, fill);
+		name[40] = 0;
+		ref.refname = name;
+
+		ref.value_type = REFTABLE_REF_VAL2;
+		set_test_hash(ref.value.val2.value, i / 4);
+		set_test_hash(ref.value.val2.target_value, 3 + i / 4);
+
+		/* 80 bytes / entry, so 3 entries per block. Yields 17
+		 */
+		/* blocks. */
+		n = reftable_writer_add_ref(w, &ref);
+		check_int(n, ==, 0);
+
+		if (!memcmp(ref.value.val2.value, want_hash, GIT_SHA1_RAWSZ) ||
+		    !memcmp(ref.value.val2.target_value, want_hash, GIT_SHA1_RAWSZ))
+			want_names[want_names_len++] = xstrdup(name);
+	}
+
+	n = reftable_writer_close(w);
+	check_int(n, ==, 0);
+
+	reftable_writer_free(w);
+	w = NULL;
+
+	block_source_from_strbuf(&source, &buf);
+
+	err = init_reader(&rd, &source, "file.ref");
+	check(!err);
+	if (!indexed)
+		rd.obj_offsets.is_present = 0;
+
+	reftable_reader_init_ref_iterator(&rd, &it);
+	err = reftable_iterator_seek_ref(&it, "");
+	check(!err);
+	reftable_iterator_destroy(&it);
+
+	err = reftable_reader_refs_for(&rd, &it, want_hash);
+	check(!err);
+
+	for (j = 0; ; j++) {
+		int err = reftable_iterator_next_ref(&it, &ref);
+		check_int(err, >=, 0);
+		if (err > 0)
+			break;
+		check_int(j, <, want_names_len);
+		check_str(ref.refname, want_names[j]);
+		reftable_ref_record_release(&ref);
+	}
+	check_int(j, ==, want_names_len);
+
+	strbuf_release(&buf);
+	free_names(want_names);
+	reftable_iterator_destroy(&it);
+	reader_close(&rd);
+}
+
+static void t_table_refs_for_no_index(void)
+{
+	t_table_refs_for(0);
+}
+
+static void t_table_refs_for_obj_index(void)
+{
+	t_table_refs_for(1);
+}
+
+static void t_write_empty_table(void)
+{
+	struct reftable_write_options opts = { 0 };
+	struct strbuf buf = STRBUF_INIT;
+	struct reftable_writer *w =
+		reftable_new_writer(&strbuf_add_void, &noop_flush, &buf, &opts);
+	struct reftable_block_source source = { 0 };
+	struct reftable_reader *rd = NULL;
+	struct reftable_ref_record rec = { 0 };
+	struct reftable_iterator it = { 0 };
+	int err;
+
+	reftable_writer_set_limits(w, 1, 1);
+
+	err = reftable_writer_close(w);
+	check_int(err, ==, REFTABLE_EMPTY_TABLE_ERROR);
+	reftable_writer_free(w);
+
+	check_int(buf.len, ==, header_size(1) + footer_size(1));
+
+	block_source_from_strbuf(&source, &buf);
+
+	err = reftable_new_reader(&rd, &source, "filename");
+	check(!err);
+
+	reftable_reader_init_ref_iterator(rd, &it);
+	err = reftable_iterator_seek_ref(&it, "");
+	check(!err);
+
+	err = reftable_iterator_next_ref(&it, &rec);
+	check_int(err, >, 0);
+
+	reftable_iterator_destroy(&it);
+	reftable_reader_free(rd);
+	strbuf_release(&buf);
+}
+
+static void t_write_object_id_min_length(void)
+{
+	struct reftable_write_options opts = {
+		.block_size = 75,
+	};
+	struct strbuf buf = STRBUF_INIT;
+	struct reftable_writer *w =
+		reftable_new_writer(&strbuf_add_void, &noop_flush, &buf, &opts);
+	struct reftable_ref_record ref = {
+		.update_index = 1,
+		.value_type = REFTABLE_REF_VAL1,
+		.value.val1 = {42},
+	};
+	int err;
+	int i;
+
+	reftable_writer_set_limits(w, 1, 1);
+
+	/* Write the same hash in many refs. If there is only 1 hash, the
+	 * disambiguating prefix is length 0 */
+	for (i = 0; i < 256; i++) {
+		char name[256];
+		snprintf(name, sizeof(name), "ref%05d", i);
+		ref.refname = name;
+		err = reftable_writer_add_ref(w, &ref);
+		check(!err);
+	}
+
+	err = reftable_writer_close(w);
+	check(!err);
+	check_int(reftable_writer_stats(w)->object_id_len, ==, 2);
+	reftable_writer_free(w);
+	strbuf_release(&buf);
+}
+
+static void t_write_object_id_length(void)
+{
+	struct reftable_write_options opts = {
+		.block_size = 75,
+	};
+	struct strbuf buf = STRBUF_INIT;
+	struct reftable_writer *w =
+		reftable_new_writer(&strbuf_add_void, &noop_flush, &buf, &opts);
+	struct reftable_ref_record ref = {
+		.update_index = 1,
+		.value_type = REFTABLE_REF_VAL1,
+		.value.val1 = {42},
+	};
+	int err;
+	int i;
+
+	reftable_writer_set_limits(w, 1, 1);
+
+	/* Write the same hash in many refs. If there is only 1 hash, the
+	 * disambiguating prefix is length 0 */
+	for (i = 0; i < 256; i++) {
+		char name[256];
+		snprintf(name, sizeof(name), "ref%05d", i);
+		ref.refname = name;
+		ref.value.val1[15] = i;
+		err = reftable_writer_add_ref(w, &ref);
+		check(!err);
+	}
+
+	err = reftable_writer_close(w);
+	check(!err);
+	check_int(reftable_writer_stats(w)->object_id_len, ==, 16);
+	reftable_writer_free(w);
+	strbuf_release(&buf);
+}
+
+static void t_write_empty_key(void)
+{
+	struct reftable_write_options opts = { 0 };
+	struct strbuf buf = STRBUF_INIT;
+	struct reftable_writer *w =
+		reftable_new_writer(&strbuf_add_void, &noop_flush, &buf, &opts);
+	struct reftable_ref_record ref = {
+		.refname = (char *) "",
+		.update_index = 1,
+		.value_type = REFTABLE_REF_DELETION,
+	};
+	int err;
+
+	reftable_writer_set_limits(w, 1, 1);
+	err = reftable_writer_add_ref(w, &ref);
+	check_int(err, ==, REFTABLE_API_ERROR);
+
+	err = reftable_writer_close(w);
+	check_int(err, ==, REFTABLE_EMPTY_TABLE_ERROR);
+	reftable_writer_free(w);
+	strbuf_release(&buf);
+}
+
+static void t_write_key_order(void)
+{
+	struct reftable_write_options opts = { 0 };
+	struct strbuf buf = STRBUF_INIT;
+	struct reftable_writer *w =
+		reftable_new_writer(&strbuf_add_void, &noop_flush, &buf, &opts);
+	struct reftable_ref_record refs[2] = {
+		{
+			.refname = (char *) "b",
+			.update_index = 1,
+			.value_type = REFTABLE_REF_SYMREF,
+			.value = {
+				.symref = (char *) "target",
+			},
+		}, {
+			.refname = (char *) "a",
+			.update_index = 1,
+			.value_type = REFTABLE_REF_SYMREF,
+			.value = {
+				.symref = (char *) "target",
+			},
+		}
+	};
+	int err;
+
+	reftable_writer_set_limits(w, 1, 1);
+	err = reftable_writer_add_ref(w, &refs[0]);
+	check(!err);
+	err = reftable_writer_add_ref(w, &refs[1]);
+	check_int(err, ==, REFTABLE_API_ERROR);
+
+	refs[0].update_index = 2;
+	err = reftable_writer_add_ref(w, &refs[0]);
+	check_int(err, ==, REFTABLE_API_ERROR);
+
+	reftable_writer_close(w);
+	reftable_writer_free(w);
+	strbuf_release(&buf);
+}
+
+static void t_write_multiple_indices(void)
+{
+	struct reftable_write_options opts = {
+		.block_size = 100,
+	};
+	struct strbuf writer_buf = STRBUF_INIT, buf = STRBUF_INIT;
+	struct reftable_block_source source = { 0 };
+	struct reftable_iterator it = { 0 };
+	const struct reftable_stats *stats;
+	struct reftable_writer *writer;
+	struct reftable_reader *reader;
+	int err, i;
+
+	writer = reftable_new_writer(&strbuf_add_void, &noop_flush, &writer_buf, &opts);
+	reftable_writer_set_limits(writer, 1, 1);
+	for (i = 0; i < 100; i++) {
+		struct reftable_ref_record ref = {
+			.update_index = 1,
+			.value_type = REFTABLE_REF_VAL1,
+			.value.val1 = {i},
+		};
+
+		strbuf_reset(&buf);
+		strbuf_addf(&buf, "refs/heads/%04d", i);
+		ref.refname = buf.buf,
+
+		err = reftable_writer_add_ref(writer, &ref);
+		check(!err);
+	}
+
+	for (i = 0; i < 100; i++) {
+		struct reftable_log_record log = {
+			.update_index = 1,
+			.value_type = REFTABLE_LOG_UPDATE,
+			.value.update = {
+				.old_hash = { i },
+				.new_hash = { i },
+			},
+		};
+
+		strbuf_reset(&buf);
+		strbuf_addf(&buf, "refs/heads/%04d", i);
+		log.refname = buf.buf,
+
+		err = reftable_writer_add_log(writer, &log);
+		check(!err);
+	}
+
+	reftable_writer_close(writer);
+
+	/*
+	 * The written data should be sufficiently large to result in indices
+	 * for each of the block types.
+	 */
+	stats = reftable_writer_stats(writer);
+	check_int(stats->ref_stats.index_offset, >, 0);
+	check_int(stats->obj_stats.index_offset, >, 0);
+	check_int(stats->log_stats.index_offset, >, 0);
+
+	block_source_from_strbuf(&source, &writer_buf);
+	err = reftable_new_reader(&reader, &source, "filename");
+	check(!err);
+
+	/*
+	 * Seeking the log uses the log index now. In case there is any
+	 * confusion regarding indices we would notice here.
+	 */
+	reftable_reader_init_log_iterator(reader, &it);
+	err = reftable_iterator_seek_log(&it, "");
+	check(!err);
+
+	reftable_iterator_destroy(&it);
+	reftable_writer_free(writer);
+	reftable_reader_free(reader);
+	strbuf_release(&writer_buf);
+	strbuf_release(&buf);
+}
+
+static void t_write_multi_level_index(void)
+{
+	struct reftable_write_options opts = {
+		.block_size = 100,
+	};
+	struct strbuf writer_buf = STRBUF_INIT, buf = STRBUF_INIT;
+	struct reftable_block_source source = { 0 };
+	struct reftable_iterator it = { 0 };
+	const struct reftable_stats *stats;
+	struct reftable_writer *writer;
+	struct reftable_reader *reader;
+	int err;
+
+	writer = reftable_new_writer(&strbuf_add_void, &noop_flush, &writer_buf, &opts);
+	reftable_writer_set_limits(writer, 1, 1);
+	for (size_t i = 0; i < 200; i++) {
+		struct reftable_ref_record ref = {
+			.update_index = 1,
+			.value_type = REFTABLE_REF_VAL1,
+			.value.val1 = {i},
+		};
+
+		strbuf_reset(&buf);
+		strbuf_addf(&buf, "refs/heads/%03" PRIuMAX, (uintmax_t)i);
+		ref.refname = buf.buf,
+
+		err = reftable_writer_add_ref(writer, &ref);
+		check(!err);
+	}
+	reftable_writer_close(writer);
+
+	/*
+	 * The written refs should be sufficiently large to result in a
+	 * multi-level index.
+	 */
+	stats = reftable_writer_stats(writer);
+	check_int(stats->ref_stats.max_index_level, ==, 2);
+
+	block_source_from_strbuf(&source, &writer_buf);
+	err = reftable_new_reader(&reader, &source, "filename");
+	check(!err);
+
+	/*
+	 * Seeking the last ref should work as expected.
+	 */
+	reftable_reader_init_ref_iterator(reader, &it);
+	err = reftable_iterator_seek_ref(&it, "refs/heads/199");
+	check(!err);
+
+	reftable_iterator_destroy(&it);
+	reftable_writer_free(writer);
+	reftable_reader_free(reader);
+	strbuf_release(&writer_buf);
+	strbuf_release(&buf);
+}
+
+static void t_corrupt_table_empty(void)
+{
+	struct strbuf buf = STRBUF_INIT;
+	struct reftable_block_source source = { 0 };
+	struct reftable_reader rd = { 0 };
+	int err;
+
+	block_source_from_strbuf(&source, &buf);
+	err = init_reader(&rd, &source, "file.log");
+	check_int(err, ==, REFTABLE_FORMAT_ERROR);
+}
+
+static void t_corrupt_table(void)
+{
+	uint8_t zeros[1024] = { 0 };
+	struct strbuf buf = STRBUF_INIT;
+	struct reftable_block_source source = { 0 };
+	struct reftable_reader rd = { 0 };
+	int err;
+	strbuf_add(&buf, zeros, sizeof(zeros));
+
+	block_source_from_strbuf(&source, &buf);
+	err = init_reader(&rd, &source, "file.log");
+	check_int(err, ==, REFTABLE_FORMAT_ERROR);
+	strbuf_release(&buf);
+}
+
+int cmd_main(int argc UNUSED, const char *argv[] UNUSED)
+{
+	TEST(t_buffer(), "strbuf works as blocksource");
+	TEST(t_corrupt_table(), "read-write on corrupted table");
+	TEST(t_corrupt_table_empty(), "read-write on an empty table");
+	TEST(t_log_buffer_size(), "buffer extension for log compression");
+	TEST(t_log_overflow(), "log overflow returns expected error");
+	TEST(t_log_write_read(), "read-write on log records");
+	TEST(t_log_zlib_corruption(), "reading corrupted log record returns expected error");
+	TEST(t_table_read_api(), "read on a table");
+	TEST(t_table_read_write_seek_index(), "read-write on a table with index");
+	TEST(t_table_read_write_seek_linear(), "read-write on a table without index (SHA1)");
+	TEST(t_table_read_write_seek_linear_sha256(), "read-write on a table without index (SHA256)");
+	TEST(t_table_read_write_sequential(), "sequential read-write on a table");
+	TEST(t_table_refs_for_no_index(), "refs-only table with no index");
+	TEST(t_table_refs_for_obj_index(), "refs-only table with index");
+	TEST(t_table_write_small_table(), "write_table works");
+	TEST(t_write_empty_key(), "write on refs with empty keys");
+	TEST(t_write_empty_table(), "read-write on empty tables");
+	TEST(t_write_key_order(), "refs must be written in increasing order");
+	TEST(t_write_multi_level_index(), "table with multi-level index");
+	TEST(t_write_multiple_indices(), "table with indices for multiple block types");
+	TEST(t_write_object_id_length(), "prefix compression on writing refs");
+	TEST(t_write_object_id_min_length(), "prefix compression on writing refs");
+
+	return test_done();
+}
diff --git a/t/unit-tests/t-strvec.c b/t/unit-tests/t-strvec.c
index c3b610dda7..5c844cf0c9 100644
--- a/t/unit-tests/t-strvec.c
+++ b/t/unit-tests/t-strvec.c
@@ -19,237 +19,193 @@
 		} \
 	} while (0)
 
-static void t_static_init(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	check_pointer_eq(vec.v, empty_strvec);
-	check_uint(vec.nr, ==, 0);
-	check_uint(vec.alloc, ==, 0);
-}
-
-static void t_dynamic_init(void)
-{
-	struct strvec vec;
-	strvec_init(&vec);
-	check_pointer_eq(vec.v, empty_strvec);
-	check_uint(vec.nr, ==, 0);
-	check_uint(vec.alloc, ==, 0);
-}
-
-static void t_clear(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_push(&vec, "foo");
-	strvec_clear(&vec);
-	check_pointer_eq(vec.v, empty_strvec);
-	check_uint(vec.nr, ==, 0);
-	check_uint(vec.alloc, ==, 0);
-}
-
-static void t_push(void)
-{
-	struct strvec vec = STRVEC_INIT;
-
-	strvec_push(&vec, "foo");
-	check_strvec(&vec, "foo", NULL);
-
-	strvec_push(&vec, "bar");
-	check_strvec(&vec, "foo", "bar", NULL);
-
-	strvec_clear(&vec);
-}
-
-static void t_pushf(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_pushf(&vec, "foo: %d", 1);
-	check_strvec(&vec, "foo: 1", NULL);
-	strvec_clear(&vec);
-}
-
-static void t_pushl(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_pushl(&vec, "foo", "bar", "baz", NULL);
-	check_strvec(&vec, "foo", "bar", "baz", NULL);
-	strvec_clear(&vec);
-}
-
-static void t_pushv(void)
-{
-	const char *strings[] = {
-		"foo", "bar", "baz", NULL,
-	};
-	struct strvec vec = STRVEC_INIT;
-
-	strvec_pushv(&vec, strings);
-	check_strvec(&vec, "foo", "bar", "baz", NULL);
-
-	strvec_clear(&vec);
-}
-
-static void t_replace_at_head(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_pushl(&vec, "foo", "bar", "baz", NULL);
-	strvec_replace(&vec, 0, "replaced");
-	check_strvec(&vec, "replaced", "bar", "baz", NULL);
-	strvec_clear(&vec);
-}
-
-static void t_replace_at_tail(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_pushl(&vec, "foo", "bar", "baz", NULL);
-	strvec_replace(&vec, 2, "replaced");
-	check_strvec(&vec, "foo", "bar", "replaced", NULL);
-	strvec_clear(&vec);
-}
-
-static void t_replace_in_between(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_pushl(&vec, "foo", "bar", "baz", NULL);
-	strvec_replace(&vec, 1, "replaced");
-	check_strvec(&vec, "foo", "replaced", "baz", NULL);
-	strvec_clear(&vec);
-}
-
-static void t_replace_with_substring(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_pushl(&vec, "foo", NULL);
-	strvec_replace(&vec, 0, vec.v[0] + 1);
-	check_strvec(&vec, "oo", NULL);
-	strvec_clear(&vec);
-}
-
-static void t_remove_at_head(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_pushl(&vec, "foo", "bar", "baz", NULL);
-	strvec_remove(&vec, 0);
-	check_strvec(&vec, "bar", "baz", NULL);
-	strvec_clear(&vec);
-}
-
-static void t_remove_at_tail(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_pushl(&vec, "foo", "bar", "baz", NULL);
-	strvec_remove(&vec, 2);
-	check_strvec(&vec, "foo", "bar", NULL);
-	strvec_clear(&vec);
-}
-
-static void t_remove_in_between(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_pushl(&vec, "foo", "bar", "baz", NULL);
-	strvec_remove(&vec, 1);
-	check_strvec(&vec, "foo", "baz", NULL);
-	strvec_clear(&vec);
-}
-
-static void t_pop_empty_array(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_pop(&vec);
-	check_strvec(&vec, NULL);
-	strvec_clear(&vec);
-}
-
-static void t_pop_non_empty_array(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_pushl(&vec, "foo", "bar", "baz", NULL);
-	strvec_pop(&vec);
-	check_strvec(&vec, "foo", "bar", NULL);
-	strvec_clear(&vec);
-}
-
-static void t_split_empty_string(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_split(&vec, "");
-	check_strvec(&vec, NULL);
-	strvec_clear(&vec);
-}
-
-static void t_split_single_item(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_split(&vec, "foo");
-	check_strvec(&vec, "foo", NULL);
-	strvec_clear(&vec);
-}
-
-static void t_split_multiple_items(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_split(&vec, "foo bar baz");
-	check_strvec(&vec, "foo", "bar", "baz", NULL);
-	strvec_clear(&vec);
-}
-
-static void t_split_whitespace_only(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_split(&vec, " \t\n");
-	check_strvec(&vec, NULL);
-	strvec_clear(&vec);
-}
-
-static void t_split_multiple_consecutive_whitespaces(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	strvec_split(&vec, "foo\n\t bar");
-	check_strvec(&vec, "foo", "bar", NULL);
-	strvec_clear(&vec);
-}
-
-static void t_detach(void)
-{
-	struct strvec vec = STRVEC_INIT;
-	const char **detached;
-
-	strvec_push(&vec, "foo");
-
-	detached = strvec_detach(&vec);
-	check_str(detached[0], "foo");
-	check_pointer_eq(detached[1], NULL);
-
-	check_pointer_eq(vec.v, empty_strvec);
-	check_uint(vec.nr, ==, 0);
-	check_uint(vec.alloc, ==, 0);
-
-	free((char *) detached[0]);
-	free(detached);
-}
-
 int cmd_main(int argc UNUSED, const char **argv UNUSED)
 {
-	TEST(t_static_init(), "static initialization");
-	TEST(t_dynamic_init(), "dynamic initialization");
-	TEST(t_clear(), "clear");
-	TEST(t_push(), "push");
-	TEST(t_pushf(), "pushf");
-	TEST(t_pushl(), "pushl");
-	TEST(t_pushv(), "pushv");
-	TEST(t_replace_at_head(), "replace at head");
-	TEST(t_replace_in_between(), "replace in between");
-	TEST(t_replace_at_tail(), "replace at tail");
-	TEST(t_replace_with_substring(), "replace with substring");
-	TEST(t_remove_at_head(), "remove at head");
-	TEST(t_remove_in_between(), "remove in between");
-	TEST(t_remove_at_tail(), "remove at tail");
-	TEST(t_pop_empty_array(), "pop with empty array");
-	TEST(t_pop_non_empty_array(), "pop with non-empty array");
-	TEST(t_split_empty_string(), "split empty string");
-	TEST(t_split_single_item(), "split single item");
-	TEST(t_split_multiple_items(), "split multiple items");
-	TEST(t_split_whitespace_only(), "split whitespace only");
-	TEST(t_split_multiple_consecutive_whitespaces(), "split multiple consecutive whitespaces");
-	TEST(t_detach(), "detach");
+	if_test ("static initialization") {
+		struct strvec vec = STRVEC_INIT;
+		check_pointer_eq(vec.v, empty_strvec);
+		check_uint(vec.nr, ==, 0);
+		check_uint(vec.alloc, ==, 0);
+	}
+
+	if_test ("dynamic initialization") {
+		struct strvec vec;
+		strvec_init(&vec);
+		check_pointer_eq(vec.v, empty_strvec);
+		check_uint(vec.nr, ==, 0);
+		check_uint(vec.alloc, ==, 0);
+	}
+
+	if_test ("clear") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_push(&vec, "foo");
+		strvec_clear(&vec);
+		check_pointer_eq(vec.v, empty_strvec);
+		check_uint(vec.nr, ==, 0);
+		check_uint(vec.alloc, ==, 0);
+	}
+
+	if_test ("push") {
+		struct strvec vec = STRVEC_INIT;
+
+		strvec_push(&vec, "foo");
+		check_strvec(&vec, "foo", NULL);
+
+		strvec_push(&vec, "bar");
+		check_strvec(&vec, "foo", "bar", NULL);
+
+		strvec_clear(&vec);
+	}
+
+	if_test ("pushf") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_pushf(&vec, "foo: %d", 1);
+		check_strvec(&vec, "foo: 1", NULL);
+		strvec_clear(&vec);
+	}
+
+	if_test ("pushl") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_pushl(&vec, "foo", "bar", "baz", NULL);
+		check_strvec(&vec, "foo", "bar", "baz", NULL);
+		strvec_clear(&vec);
+	}
+
+	if_test ("pushv") {
+		const char *strings[] = {
+			"foo", "bar", "baz", NULL,
+		};
+		struct strvec vec = STRVEC_INIT;
+
+		strvec_pushv(&vec, strings);
+		check_strvec(&vec, "foo", "bar", "baz", NULL);
+
+		strvec_clear(&vec);
+	}
+
+	if_test ("replace at head") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_pushl(&vec, "foo", "bar", "baz", NULL);
+		strvec_replace(&vec, 0, "replaced");
+		check_strvec(&vec, "replaced", "bar", "baz", NULL);
+		strvec_clear(&vec);
+	}
+
+	if_test ("replace at tail") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_pushl(&vec, "foo", "bar", "baz", NULL);
+		strvec_replace(&vec, 2, "replaced");
+		check_strvec(&vec, "foo", "bar", "replaced", NULL);
+		strvec_clear(&vec);
+	}
+
+	if_test ("replace in between") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_pushl(&vec, "foo", "bar", "baz", NULL);
+		strvec_replace(&vec, 1, "replaced");
+		check_strvec(&vec, "foo", "replaced", "baz", NULL);
+		strvec_clear(&vec);
+	}
+
+	if_test ("replace with substring") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_pushl(&vec, "foo", NULL);
+		strvec_replace(&vec, 0, vec.v[0] + 1);
+		check_strvec(&vec, "oo", NULL);
+		strvec_clear(&vec);
+	}
+
+	if_test ("remove at head") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_pushl(&vec, "foo", "bar", "baz", NULL);
+		strvec_remove(&vec, 0);
+		check_strvec(&vec, "bar", "baz", NULL);
+		strvec_clear(&vec);
+	}
+
+	if_test ("remove at tail") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_pushl(&vec, "foo", "bar", "baz", NULL);
+		strvec_remove(&vec, 2);
+		check_strvec(&vec, "foo", "bar", NULL);
+		strvec_clear(&vec);
+	}
+
+	if_test ("remove in between") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_pushl(&vec, "foo", "bar", "baz", NULL);
+		strvec_remove(&vec, 1);
+		check_strvec(&vec, "foo", "baz", NULL);
+		strvec_clear(&vec);
+	}
+
+	if_test ("pop with empty array") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_pop(&vec);
+		check_strvec(&vec, NULL);
+		strvec_clear(&vec);
+	}
+
+	if_test ("pop with non-empty array") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_pushl(&vec, "foo", "bar", "baz", NULL);
+		strvec_pop(&vec);
+		check_strvec(&vec, "foo", "bar", NULL);
+		strvec_clear(&vec);
+	}
+
+	if_test ("split empty string") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_split(&vec, "");
+		check_strvec(&vec, NULL);
+		strvec_clear(&vec);
+	}
+
+	if_test ("split single item") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_split(&vec, "foo");
+		check_strvec(&vec, "foo", NULL);
+		strvec_clear(&vec);
+	}
+
+	if_test ("split multiple items") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_split(&vec, "foo bar baz");
+		check_strvec(&vec, "foo", "bar", "baz", NULL);
+		strvec_clear(&vec);
+	}
+
+	if_test ("split whitespace only") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_split(&vec, " \t\n");
+		check_strvec(&vec, NULL);
+		strvec_clear(&vec);
+	}
+
+	if_test ("split multiple consecutive whitespaces") {
+		struct strvec vec = STRVEC_INIT;
+		strvec_split(&vec, "foo\n\t bar");
+		check_strvec(&vec, "foo", "bar", NULL);
+		strvec_clear(&vec);
+	}
+
+	if_test ("detach") {
+		struct strvec vec = STRVEC_INIT;
+		const char **detached;
+
+		strvec_push(&vec, "foo");
+
+		detached = strvec_detach(&vec);
+		check_str(detached[0], "foo");
+		check_pointer_eq(detached[1], NULL);
+
+		check_pointer_eq(vec.v, empty_strvec);
+		check_uint(vec.nr, ==, 0);
+		check_uint(vec.alloc, ==, 0);
+
+		free((char *) detached[0]);
+		free(detached);
+	}
+
 	return test_done();
 }
diff --git a/t/unit-tests/test-lib.c b/t/unit-tests/test-lib.c
index 3c513ce59a..fa1f95965c 100644
--- a/t/unit-tests/test-lib.c
+++ b/t/unit-tests/test-lib.c
@@ -16,6 +16,8 @@ static struct {
 	unsigned running :1;
 	unsigned skip_all :1;
 	unsigned todo :1;
+	char location[100];
+	char description[100];
 } ctx = {
 	.lazy_plan = 1,
 	.result = RESULT_NONE,
@@ -125,6 +127,8 @@ void test_plan(int count)
 
 int test_done(void)
 {
+	if (ctx.running && ctx.location[0] && ctx.description[0])
+		test__run_end(1, ctx.location, "%s", ctx.description);
 	assert(!ctx.running);
 
 	if (ctx.lazy_plan)
@@ -167,13 +171,38 @@ void test_skip_all(const char *format, ...)
 	va_end(ap);
 }
 
+void test__run_describe(const char *location, const char *format, ...)
+{
+	va_list ap;
+	int len;
+
+	assert(ctx.running);
+	assert(!ctx.location[0]);
+	assert(!ctx.description[0]);
+
+	xsnprintf(ctx.location, sizeof(ctx.location), "%s",
+		  make_relative(location));
+
+	va_start(ap, format);
+	len = vsnprintf(ctx.description, sizeof(ctx.description), format, ap);
+	va_end(ap);
+	if (len < 0)
+		die("unable to format message: %s", format);
+	if (len >= sizeof(ctx.description))
+		BUG("ctx.description too small to format %s", format);
+}
+
 int test__run_begin(void)
 {
+	if (ctx.running && ctx.location[0] && ctx.description[0])
+		test__run_end(1, ctx.location, "%s", ctx.description);
 	assert(!ctx.running);
 
 	ctx.count++;
 	ctx.result = RESULT_NONE;
 	ctx.running = 1;
+	ctx.location[0] = '\0';
+	ctx.description[0] = '\0';
 
 	return ctx.skip_all;
 }
@@ -264,7 +293,12 @@ static void test_todo(void)
 
 int test_assert(const char *location, const char *check, int ok)
 {
-	assert(ctx.running);
+	if (!ctx.running) {
+		test_msg("BUG: check outside of test at %s",
+			 make_relative(location));
+		ctx.failed = 1;
+		return 0;
+	}
 
 	if (ctx.result == RESULT_SKIP) {
 		test_msg("skipping check '%s' at %s", check,
diff --git a/t/unit-tests/test-lib.h b/t/unit-tests/test-lib.h
index c59f646fd9..e4b234697f 100644
--- a/t/unit-tests/test-lib.h
+++ b/t/unit-tests/test-lib.h
@@ -15,6 +15,23 @@
 		      TEST_LOCATION(),  __VA_ARGS__)
 
 /*
+ * Run a test unless test_skip_all() has been called.  Acts like a
+ * conditional; the test body is expected as a statement or block after
+ * the closing parenthesis.  The description for each test should be
+ * unique.  E.g.:
+ *
+ *  if_test ("something else %d %d", arg1, arg2) {
+ *          prepare();
+ *          test_something_else(arg1, arg2);
+ *          cleanup();
+ *  }
+ */
+#define if_test(...)							\
+	if (test__run_begin() ?						\
+	    (test__run_end(0, TEST_LOCATION(),  __VA_ARGS__), 0) :	\
+	    (test__run_describe(TEST_LOCATION(),  __VA_ARGS__), 1))
+
+/*
  * Print a test plan, should be called before any tests. If the number
  * of tests is not known in advance test_done() will automatically
  * print a plan at the end of the test program.
@@ -154,6 +171,9 @@ union test__tmp {
 
 extern union test__tmp test__tmp[2];
 
+__attribute__((format (printf, 2, 3)))
+void test__run_describe(const char *, const char *, ...);
+
 int test__run_begin(void);
 __attribute__((format (printf, 3, 4)))
 int test__run_end(int, const char *, const char *, ...);