commit fcf4954cc83570818d6be15f2117e31cc3eda34e Author: Nick Mathewson nickm@torproject.org Date: Thu Jul 30 10:40:18 2020 -0400

Add a unit test for write_str_to_file_if_not_equal() --- src/test/test_util.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+)

diff --git a/src/test/test_util.c b/src/test/test_util.c index 5fe9617f89..1bbe747ec1 100644 --- a/src/test/test_util.c +++ b/src/test/test_util.c @@ -357,6 +357,55 @@ test_util_write_chunks_to_file(void *arg) tor_free(temp_str); }

+/* Test write_str_to_file_if_not_equal(). */ +static void +test_util_write_str_if_changed(void *arg) +{ + (void)arg; + char *fname = tor_strdup(get_fname("write_if_changed")); + char *s = NULL; + int rv; + const char str1[] = "The wombat lives across the seas"; + const char str2[] = "Among the far Antipodes"; /* -- Ogden Nash */ + + /* We can create files. */ + rv = write_str_to_file_if_not_equal(fname, str1); + tt_int_op(rv, OP_EQ, 0); + s = read_file_to_str(fname, 0, NULL); + tt_str_op(s, OP_EQ, str1); + tor_free(s); + + /* We can replace files. */ + rv = write_str_to_file_if_not_equal(fname, str2); + tt_int_op(rv, OP_EQ, 0); + s = read_file_to_str(fname, 0, NULL); + tt_str_op(s, OP_EQ, str2); + tor_free(s); + + /* Make sure we don't replace files when they're equal. (That's the whole + * point of the function we're testing. */ + /* First, change the mtime of the file so that we can tell whether we + * replaced it. */ + const time_t now = time(NULL); + const time_t five_sec_ago = now - 5; + set_file_mtime(fname, five_sec_ago); + rv = write_str_to_file_if_not_equal(fname, str2); + tt_int_op(rv, OP_EQ, 0); + /* Make sure that the file's mtime is unchanged... */ + struct stat st; + rv = stat(fname, &st); + tt_int_op(rv, OP_EQ, 0); + tt_i64_op(st.st_mtime, OP_EQ, five_sec_ago); + /* And make sure its contents are unchanged. */ + s = read_file_to_str(fname, 0, NULL); + tt_str_op(s, OP_EQ, str2); + tor_free(s); + + done: + tor_free(fname); + tor_free(s); +} + #ifndef COCCI #define _TFE(a, b, f) tt_int_op((a).f, OP_EQ, (b).f) /** test the minimum set of struct tm fields needed for a unique epoch value @@ -6557,6 +6606,7 @@ struct testcase_t util_tests[] = { UTIL_TEST(read_file_eof_zero_bytes, 0), UTIL_TEST(read_file_endlines, 0), UTIL_TEST(write_chunks_to_file, 0), + UTIL_TEST(write_str_if_changed, 0), UTIL_TEST(mathlog, 0), UTIL_TEST(fraction, 0), UTIL_TEST(weak_random, 0),