From 67a579aab01b605f08d0d457efff2f847c7b0a9a Mon Sep 17 00:00:00 2001
From: Tim Schumacher <timschumi@gmx.de>
Date: Tue, 21 Sep 2021 23:07:03 +0200
Subject: [PATCH] AK: Add a basic formatter for wchar_t

---
 AK/Format.cpp           | 13 +++++++++++++
 AK/Format.h             |  4 ++++
 Tests/AK/TestFormat.cpp | 14 ++++++++++++++
 3 files changed, 31 insertions(+)

diff --git a/AK/Format.cpp b/AK/Format.cpp
index 8e691a5e36..c4ebe8e59f 100644
--- a/AK/Format.cpp
+++ b/AK/Format.cpp
@@ -688,6 +688,19 @@ void Formatter<char>::format(FormatBuilder& builder, char value)
         return formatter.format(builder, { &value, 1 });
     }
 }
+void Formatter<wchar_t>::format(FormatBuilder& builder, wchar_t value)
+{
+    if (m_mode == Mode::Binary || m_mode == Mode::BinaryUppercase || m_mode == Mode::Decimal || m_mode == Mode::Octal || m_mode == Mode::Hexadecimal || m_mode == Mode::HexadecimalUppercase) {
+        Formatter<u32> formatter { *this };
+        return formatter.format(builder, static_cast<u32>(value));
+    } else {
+        StringBuilder codepoint;
+        codepoint.append_code_point(value);
+
+        Formatter<StringView> formatter { *this };
+        return formatter.format(builder, codepoint.to_string());
+    }
+}
 void Formatter<bool>::format(FormatBuilder& builder, bool value)
 {
     if (m_mode == Mode::Binary || m_mode == Mode::BinaryUppercase || m_mode == Mode::Decimal || m_mode == Mode::Octal || m_mode == Mode::Hexadecimal || m_mode == Mode::HexadecimalUppercase) {
diff --git a/AK/Format.h b/AK/Format.h
index 657be6d8e3..953e062b8b 100644
--- a/AK/Format.h
+++ b/AK/Format.h
@@ -423,6 +423,10 @@ struct Formatter<char> : StandardFormatter {
     void format(FormatBuilder&, char value);
 };
 template<>
+struct Formatter<wchar_t> : StandardFormatter {
+    void format(FormatBuilder& builder, wchar_t value);
+};
+template<>
 struct Formatter<bool> : StandardFormatter {
     void format(FormatBuilder&, bool value);
 };
diff --git a/Tests/AK/TestFormat.cpp b/Tests/AK/TestFormat.cpp
index 28696cce28..a4cc1f642f 100644
--- a/Tests/AK/TestFormat.cpp
+++ b/Tests/AK/TestFormat.cpp
@@ -323,3 +323,17 @@ TEST_CASE(vector_format)
         EXPECT_EQ(String::formatted("{}", v), "[ [ 1, 2 ], [ 3, 4 ] ]");
     }
 }
+
+TEST_CASE(format_wchar)
+{
+    EXPECT_EQ(String::formatted("{}", L'a'), "a");
+    EXPECT_EQ(String::formatted("{}", L'\U0001F41E'), "\xF0\x9F\x90\x9E");
+    EXPECT_EQ(String::formatted("{:x}", L'a'), "61");
+    EXPECT_EQ(String::formatted("{:x}", L'\U0001F41E'), "1f41e");
+    EXPECT_EQ(String::formatted("{:d}", L'a'), "97");
+    EXPECT_EQ(String::formatted("{:d}", L'\U0001F41E'), "128030");
+
+    EXPECT_EQ(String::formatted("{:6}", L'a'), "a     ");
+    EXPECT_EQ(String::formatted("{:6d}", L'a'), "    97");
+    EXPECT_EQ(String::formatted("{:#x}", L'\U0001F41E'), "0x1f41e");
+}