kunit: string-stream: Improve testing of string_stream

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.

Adds string_stream_append_empty_string_test() to test that adding an
empty string to a string_stream doesn't create a new empty fragment.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

diff --git a/lib/kunit/string-stream-test.c b/lib/kunit/string-stream-test.c
index 110f3a993250f7d9475f0abf6a5928e2c3a8e676..7e17307ca78c5afd69db7cabb240ec513b600d43 100644 (file)
--- a/lib/kunit/string-stream-test.c
+++ b/lib/kunit/string-stream-test.c
@@ -11,38 +11,239 @@
 
 #include "string-stream.h"
 
-static void string_stream_test_empty_on_creation(struct kunit *test)
+static char *get_concatenated_string(struct kunit *test, struct string_stream *stream)
 {
-       struct string_stream *stream = alloc_string_stream(test, GFP_KERNEL);
+       char *str = string_stream_get_string(stream);
 
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, str);
+
+       return str;
+}
+
+/* string_stream object is initialized correctly. */
+static void string_stream_init_test(struct kunit *test)
+{
+       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_TRUE(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;
+       char line[60];
+       char *concat_string, *pos, *string_end;
+       size_t len, total_len;
+       int num_lines, i;
+
+       stream = alloc_string_stream(test, GFP_KERNEL);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, 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 = get_concatenated_string(test, 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);
+}
+
+/* Add a series of lines of variable length to a string_stream. */
+static void string_stream_variable_length_line_test(struct kunit *test)
+{
+       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;
+
+       stream = alloc_string_stream(test, GFP_KERNEL);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
+
+       /*
+        * 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 = get_concatenated_string(test, 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)
 {
-       struct string_stream *stream = alloc_string_stream(test, GFP_KERNEL);
+       static const char * const strings_1[] = {
+               "one", "two", "three", "four", "five", "six",
+               "seven", "eight", "nine", "ten",
+       };
+       static const char * const strings_2[] = {
+               "Apple", "Pear", "Orange", "Banana", "Grape", "Apricot",
+       };
+       struct string_stream *stream_1, *stream_2;
+       const char *stream1_content_before_append, *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(get_concatenated_string(test, stream_1)), 0);
 
-       string_stream_add(stream, "Foo");
+       /* 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]);
 
-       KUNIT_EXPECT_FALSE(test, string_stream_is_empty(stream));
+       stream1_content_before_append = get_concatenated_string(test, stream_1);
+
+       /* Append content of empty stream to non-empty stream */
+       string_stream_append(stream_1, stream_2);
+       KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream_1),
+                          stream1_content_before_append);
+
+       /* 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 = get_concatenated_string(test, stream_2);
+       combined_length = strlen(stream1_content_before_append) + 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",
+                stream1_content_before_append, stream_2_content);
+
+       KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, 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, get_concatenated_string(test, stream_1), stream_2_content);
 }
 
-static void string_stream_test_get_string(struct kunit *test)
+/* Adding an empty string should not create a fragment. */
+static void string_stream_append_empty_string_test(struct kunit *test)
 {
-       struct string_stream *stream = alloc_string_stream(test, GFP_KERNEL);
-       char *output;
+       struct string_stream *stream;
+       int original_frag_count;
+
+       stream = alloc_string_stream(test, GFP_KERNEL);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
+
+       /* Formatted empty string */
+       string_stream_add(stream, "%s", "");
+       KUNIT_EXPECT_TRUE(test, string_stream_is_empty(stream));
+       KUNIT_EXPECT_TRUE(test, list_empty(&stream->fragments));
 
-       string_stream_add(stream, "Foo");
-       string_stream_add(stream, " %s", "bar");
+       /* Adding an empty string to a non-empty stream */
+       string_stream_add(stream, "Add this line");
+       original_frag_count = list_count_nodes(&stream->fragments);
 
-       output = string_stream_get_string(stream);
-       KUNIT_ASSERT_STREQ(test, output, "Foo bar");
+       string_stream_add(stream, "%s", "");
+       KUNIT_EXPECT_EQ(test, list_count_nodes(&stream->fragments), original_frag_count);
+       KUNIT_EXPECT_STREQ(test, get_concatenated_string(test, stream), "Add this line");
 }
 
 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),
+       KUNIT_CASE(string_stream_append_empty_string_test),
        {}
 };