Tests: Add tests for most functions in AK/CharacterType.h

Author: https://github.com/MaxWipfli
Commit: https://github.com/SerenityOS/serenity/commit/1c9d87c4558
Pull-request: https://github.com/SerenityOS/serenity/pull/7684
Reviewed-by: https://github.com/awesomekling
Reviewed-by: https://github.com/bgianfo ✅

Tests/AK/CMakeLists.txt

@@ -10,6 +10,7 @@ set(AK_TEST_SOURCES
     TestBitCast.cpp
     TestBitmap.cpp
     TestByteBuffer.cpp
+    TestCharacterTypes.cpp
     TestChecked.cpp
     TestCircularDeque.cpp
     TestCircularDuplexStream.cpp

Tests/AK/TestCharacterTypes.cpp

@@ -0,0 +1,135 @@
+/*
+ * Copyright (c) 2021, Max Wipfli <mail@maxwipfli.ch>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibTest/TestCase.h>
+
+#include <AK/CharacterTypes.h>
+#include <ctype.h>
+
+#define ASCII 0x80
+#define UNICODE 0x10FFFF + 100
+
+void compare_bool_output_over(u32 range, auto& old_function, auto& new_function)
+{
+    bool result1 = false;
+    bool result2 = false;
+    for (u32 i = 0; i < range; ++i) {
+        EXPECT_EQ(result1 = (old_function(i) > 0), result2 = (new_function(i) > 0));
+        if (result1 != result2)
+            dbgln("Function input value was {}.", i);
+    }
+}
+
+void compare_value_output_over(u32 range, auto& old_function, auto& new_function)
+{
+    i64 result1 = 0;
+    i64 result2 = 0;
+    for (u32 i = 0; i < range; ++i) {
+        EXPECT_EQ(result1 = old_function(i), result2 = new_function(i));
+        if (result1 != result2)
+            dbgln("Function input value was {}.", i);
+    }
+}
+
+TEST_CASE(is_ascii)
+{
+    compare_bool_output_over(UNICODE, isascii, is_ascii);
+}
+
+TEST_CASE(is_ascii_alphanumeric)
+{
+    compare_bool_output_over(ASCII, isalnum, is_ascii_alphanumeric);
+}
+
+TEST_CASE(is_ascii_blank)
+{
+    compare_bool_output_over(ASCII, isblank, is_ascii_blank);
+}
+
+TEST_CASE(is_ascii_c0_control)
+{
+    compare_bool_output_over(ASCII - 1, iscntrl, is_ascii_c0_control);
+}
+
+TEST_CASE(is_ascii_control)
+{
+    compare_bool_output_over(ASCII, iscntrl, is_ascii_control);
+}
+
+TEST_CASE(is_ascii_digit)
+{
+    compare_bool_output_over(ASCII, isdigit, is_ascii_digit);
+}
+
+TEST_CASE(is_ascii_graphical)
+{
+    compare_bool_output_over(ASCII, isgraph, is_ascii_graphical);
+}
+
+TEST_CASE(is_ascii_hex_digit)
+{
+    compare_bool_output_over(ASCII, isxdigit, is_ascii_hex_digit);
+}
+
+TEST_CASE(is_ascii_lower_alpha)
+{
+    compare_bool_output_over(ASCII, islower, is_ascii_lower_alpha);
+}
+
+TEST_CASE(is_ascii_printable)
+{
+    compare_bool_output_over(ASCII, isprint, is_ascii_printable);
+}
+
+TEST_CASE(is_ascii_punctuation)
+{
+    compare_bool_output_over(ASCII, ispunct, is_ascii_punctuation);
+}
+
+TEST_CASE(is_ascii_space)
+{
+    compare_bool_output_over(ASCII, isspace, is_ascii_space);
+}
+
+TEST_CASE(is_ascii_upper_alpha)
+{
+    compare_bool_output_over(ASCII, isupper, is_ascii_upper_alpha);
+}
+
+TEST_CASE(to_ascii_lowercase)
+{
+    compare_value_output_over(UNICODE, tolower, to_ascii_lowercase);
+}
+
+TEST_CASE(to_ascii_uppercase)
+{
+    compare_value_output_over(UNICODE, toupper, to_ascii_uppercase);
+}
+
+TEST_CASE(parse_ascii_digit)
+{
+    EXPECT_EQ(parse_ascii_digit('0'), 0u);
+    EXPECT_EQ(parse_ascii_digit('9'), 9u);
+    EXPECT_CRASH("parsing invalid ASCII digit", [] {
+        parse_ascii_digit('a');
+        return Test::Crash::Failure::DidNotCrash;
+    });
+    EXPECT_CRASH("parsing invalid unicode digit", [] {
+        parse_ascii_digit(0x00A9);
+        return Test::Crash::Failure::DidNotCrash;
+    });
+}
+
+TEST_CASE(parse_ascii_hex_digit)
+{
+    EXPECT_EQ(parse_ascii_hex_digit('0'), 0u);
+    EXPECT_EQ(parse_ascii_hex_digit('F'), 15u);
+    EXPECT_EQ(parse_ascii_hex_digit('f'), 15u);
+    EXPECT_CRASH("parsing invalid ASCII hex digit", [] {
+        parse_ascii_hex_digit('g');
+        return Test::Crash::Failure::DidNotCrash;
+    });
+}