[PATCH v4 01/10] kunit: string-stream: Improve testing of string_stream

Richard Fitzgerald
2023-08-14T13:24:25Z

Replace the minimal tests with more-thorough testing.

string_stream_init_test() tests that struct string_stream is
initialized correctly.

string_stream_line_add_test() adds a series of numbered lines and
checks that the resulting string contains all the lines.

string_stream_variable_length_line_test() adds a large number of
lines of varying length to create many fragments, then tests that all
lines are present.

string_stream_append_test() tests various cases of using
string_stream_append() to append the content of one stream to another.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
lib/kunit/string-stream-test.c | 200 ++++++++++++++++++++++++++++++---
1 file changed, 184 insertions(+), 16 deletions(-)

diff --git a/lib/kunit/string-stream-test.c b/lib/kunit/string-stream-test.c
index 110f3a993250..1d46d5f06d2a 100644
--- a/lib/kunit/string-stream-test.c
+++ b/lib/kunit/string-stream-test.c
@@ -11,38 +11,206 @@

#include "string-stream.h"

-static void string_stream_test_empty_on_creation(struct kunit *test)
+/* string_stream object is initialized correctly. */
+static void string_stream_init_test(struct kunit *test)
{
- struct string_stream *stream = alloc_string_stream(test, GFP_KERNEL);
+ struct string_stream *stream;
+
+ stream = alloc_string_stream(test, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
+
+ KUNIT_EXPECT_EQ(test, stream->length, 0);
+ KUNIT_EXPECT_TRUE(test, list_empty(&stream->fragments));
+ KUNIT_EXPECT_PTR_EQ(test, stream->test, test);
+ KUNIT_EXPECT_EQ(test, stream->gfp, GFP_KERNEL);

KUNIT_EXPECT_TRUE(test, string_stream_is_empty(stream));
}

-static void string_stream_test_not_empty_after_add(struct kunit *test)
+/*
+ * Add a series of lines to a string_stream. Check that all lines
+ * appear in the correct order and no characters are dropped.
+ */
+static void string_stream_line_add_test(struct kunit *test)
{
- struct string_stream *stream = alloc_string_stream(test, GFP_KERNEL);
+ struct string_stream *stream;
+ char line[60];
+ char *concat_string, *pos, *string_end;
+ size_t len, total_len;
+ int num_lines, i;

- string_stream_add(stream, "Foo");
+ stream = alloc_string_stream(test, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);

- KUNIT_EXPECT_FALSE(test, string_stream_is_empty(stream));
+ /* Add series of sequence numbered lines */
+ total_len = 0;
+ for (i = 0; i < 100; ++i) {
+ len = snprintf(line, sizeof(line),
+ "The quick brown fox jumps over the lazy penguin %d\n", i);
+
+ /* Sanity-check that our test string isn't truncated */
+ KUNIT_ASSERT_LT(test, len, sizeof(line));
+
+ string_stream_add(stream, line);
+ total_len += len;
+ }
+ num_lines = i;
+
+ concat_string = string_stream_get_string(stream);
+ KUNIT_EXPECT_NOT_ERR_OR_NULL(test, concat_string);
+ KUNIT_EXPECT_EQ(test, strlen(concat_string), total_len);
+
+ /*
+ * Split the concatenated string at the newlines and check that
+ * all the original added strings are present.
+ */
+ pos = concat_string;
+ for (i = 0; i < num_lines; ++i) {
+ string_end = strchr(pos, '\n');
+ KUNIT_EXPECT_NOT_NULL(test, string_end);
+
+ /* Convert to NULL-terminated string */
+ *string_end = '\0';
+
+ snprintf(line, sizeof(line),
+ "The quick brown fox jumps over the lazy penguin %d", i);
+ KUNIT_EXPECT_STREQ(test, pos, line);
+
+ pos = string_end + 1;
+ }
+
+ /* There shouldn't be any more data after this */
+ KUNIT_EXPECT_EQ(test, strlen(pos), 0);
}

-static void string_stream_test_get_string(struct kunit *test)
+/* Add a series of lines of variable length to a string_stream. */
+static void string_stream_variable_length_line_test(struct kunit *test)
{
- struct string_stream *stream = alloc_string_stream(test, GFP_KERNEL);
- char *output;
+ static const char line[] =
+ "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+ " 0123456789!$%^&*()_-+={}[]:;@'~#<>,.?/|";
+ struct string_stream *stream;
+ struct rnd_state rnd;
+ char *concat_string, *pos, *string_end;
+ size_t offset, total_len;
+ int num_lines, i;

- string_stream_add(stream, "Foo");
- string_stream_add(stream, " %s", "bar");
+ stream = alloc_string_stream(test, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);

- output = string_stream_get_string(stream);
- KUNIT_ASSERT_STREQ(test, output, "Foo bar");
+ /*
+ * Log many lines of varying lengths until we have created
+ * many fragments.
+ * The "randomness" must be repeatable.
+ */
+ prandom_seed_state(&rnd, 3141592653589793238ULL);
+ total_len = 0;
+ for (i = 0; i < 100; ++i) {
+ offset = prandom_u32_state(&rnd) % (sizeof(line) - 1);
+ string_stream_add(stream, "%s\n", &line[offset]);
+ total_len += sizeof(line) - offset;
+ }
+ num_lines = i;
+
+ concat_string = string_stream_get_string(stream);
+ KUNIT_EXPECT_NOT_ERR_OR_NULL(test, concat_string);
+ KUNIT_EXPECT_EQ(test, strlen(concat_string), total_len);
+
+ /*
+ * Split the concatenated string at the newlines and check that
+ * all the original added strings are present.
+ */
+ prandom_seed_state(&rnd, 3141592653589793238ULL);
+ pos = concat_string;
+ for (i = 0; i < num_lines; ++i) {
+ string_end = strchr(pos, '\n');
+ KUNIT_EXPECT_NOT_NULL(test, string_end);
+
+ /* Convert to NULL-terminated string */
+ *string_end = '\0';
+
+ offset = prandom_u32_state(&rnd) % (sizeof(line) - 1);
+ KUNIT_EXPECT_STREQ(test, pos, &line[offset]);
+
+ pos = string_end + 1;
+ }
+
+ /* There shouldn't be any more data after this */
+ KUNIT_EXPECT_EQ(test, strlen(pos), 0);
+}
+
+/* Appending the content of one string stream to another. */
+static void string_stream_append_test(struct kunit *test)
+{
+ static const char * const strings_1[] = {
+ "one", "two", "three", "four", "five", "six",
+ "seven", "eight", "nine", "ten",
+ };
+ static const char * const strings_2[] = {
+ "ONE", "TWO", "THREE", "FOUR", "FIVE", "SIZE",
+ "SEVEN", "EIGHT", "NINE", "TEN",
+ };
+ struct string_stream *stream_1, *stream_2;
+ const char *original_content, *stream_2_content;
+ char *combined_content;
+ size_t combined_length;
+ int i;
+
+ stream_1 = alloc_string_stream(test, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_1);
+
+ stream_2 = alloc_string_stream(test, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_2);
+
+ /* Append content of empty stream to empty stream */
+ string_stream_append(stream_1, stream_2);
+ KUNIT_EXPECT_EQ(test, strlen(string_stream_get_string(stream_1)), 0);
+
+ /* Add some data to stream_1 */
+ for (i = 0; i < ARRAY_SIZE(strings_1); ++i)
+ string_stream_add(stream_1, "%s\n", strings_1[i]);
+
+ original_content = string_stream_get_string(stream_1);
+
+ /* Append content of empty stream to non-empty stream */
+ string_stream_append(stream_1, stream_2);
+ KUNIT_EXPECT_STREQ(test, string_stream_get_string(stream_1), original_content);
+
+ /* Add some data to stream_2 */
+ for (i = 0; i < ARRAY_SIZE(strings_2); ++i)
+ string_stream_add(stream_2, "%s\n", strings_2[i]);
+
+ /* Append content of non-empty stream to non-empty stream */
+ string_stream_append(stream_1, stream_2);
+
+ /*
+ * End result should be the original content of stream_1 plus
+ * the content of stream_2.
+ */
+ stream_2_content = string_stream_get_string(stream_2);
+ combined_length = strlen(original_content) + strlen(stream_2_content);
+ combined_length++; /* for terminating \0 */
+ combined_content = kunit_kmalloc(test, combined_length, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, combined_content);
+ snprintf(combined_content, combined_length, "%s%s", original_content, stream_2_content);
+
+ KUNIT_EXPECT_STREQ(test, string_stream_get_string(stream_1), combined_content);
+
+ /* Append content of non-empty stream to empty stream */
+ string_stream_destroy(stream_1);
+
+ stream_1 = alloc_string_stream(test, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream_1);
+
+ string_stream_append(stream_1, stream_2);
+ KUNIT_EXPECT_STREQ(test, string_stream_get_string(stream_1), stream_2_content);
}

static struct kunit_case string_stream_test_cases[] = {
- KUNIT_CASE(string_stream_test_empty_on_creation),
- KUNIT_CASE(string_stream_test_not_empty_after_add),
- KUNIT_CASE(string_stream_test_get_string),
+ KUNIT_CASE(string_stream_init_test),
+ KUNIT_CASE(string_stream_line_add_test),
+ KUNIT_CASE(string_stream_variable_length_line_test),
+ KUNIT_CASE(string_stream_append_test),
{}
};

--
2.30.2