diff --git a/tests/libluna/TestFormat.cpp b/tests/libluna/TestFormat.cpp
index 05bda4c5..955d342c 100644
--- a/tests/libluna/TestFormat.cpp
+++ b/tests/libluna/TestFormat.cpp
@@ -82,6 +82,15 @@ TestResult test_positive_signed_integer_format()
     test_success;
 }
 
+TestResult test_positive_signed_integer_format_with_empty_sign()
+{
+    auto fmt = TRY(String::format("% d"_sv, 653));
+
+    validate(fmt.view() == " 653");
+
+    test_success;
+}
+
 TestResult test_format_zero_with_explicit_zero_precision()
 {
     auto fmt = TRY(String::format("%.0d"_sv, 0));
@@ -118,6 +127,159 @@ TestResult test_uppercase_hex_format()
     test_success;
 }
 
+TestResult test_integer_format_with_width()
+{
+    auto fmt = TRY(String::format("%6d"_sv, 42));
+
+    validate(fmt.view() == "    42");
+
+    test_success;
+}
+
+TestResult test_zero_padded_integer_format_with_width()
+{
+    auto fmt = TRY(String::format("%06d"_sv, 42));
+
+    validate(fmt.view() == "000042");
+
+    test_success;
+}
+
+TestResult test_integer_format_with_precision()
+{
+    auto fmt = TRY(String::format("%.6d"_sv, 42));
+
+    validate(fmt.view() == "000042");
+
+    test_success;
+}
+
+TestResult test_alternate_integer_format_with_width()
+{
+    auto fmt = TRY(String::format("%#6x"_sv, 66));
+
+    validate(fmt.view() == "  0x42");
+
+    test_success;
+}
+
+TestResult test_zero_padded_alternate_integer_format_with_width()
+{
+    auto fmt = TRY(String::format("%0#6x"_sv, 66));
+
+    validate(fmt.view() == "0x0042");
+
+    test_success;
+}
+
+TestResult test_alternate_integer_format_with_precision()
+{
+    auto fmt = TRY(String::format("%#.6x"_sv, 66));
+
+    validate(fmt.view() == "0x000042");
+
+    test_success;
+}
+
+TestResult test_integer_format_left_align()
+{
+    auto fmt = TRY(String::format("%-6d"_sv, 42));
+
+    validate(fmt.view() == "42    ");
+
+    test_success;
+}
+
+TestResult test_integer_format_left_align_override_zero_pad()
+{
+    auto fmt = TRY(String::format("%-06d"_sv, 42));
+
+    validate(fmt.view() == "42    ");
+
+    test_success;
+}
+
+TestResult test_integer_format_left_align_with_alternate_format()
+{
+    auto fmt = TRY(String::format("%#-6o"_sv, 0755));
+
+    validate(fmt.view() == "0755  ");
+
+    test_success;
+}
+
+TestResult test_integer_format_left_align_with_alternate_format_and_precision()
+{
+    auto fmt = TRY(String::format("%#-8.5x"_sv, 0x44bb));
+
+    validate(fmt.view() == "0x044bb ");
+
+    test_success;
+}
+
+TestResult test_va_integer_width()
+{
+    auto fmt = TRY(String::format("%0*d"_sv, 4, 42));
+
+    validate(fmt.view() == "0042");
+
+    test_success;
+}
+
+TestResult test_va_integer_precision()
+{
+    auto fmt = TRY(String::format("%0.*d"_sv, 4, 42));
+
+    validate(fmt.view() == "0042");
+
+    test_success;
+}
+
+TestResult test_no_precision_assumed_as_zero()
+{
+    auto fmt = TRY(String::format("%.d"_sv, 42));
+
+    validate(fmt.view() == "42");
+
+    test_success;
+}
+
+TestResult test_no_precision_assumed_as_explicit_zero()
+{
+    auto fmt = TRY(String::format("%.d"_sv, 0));
+
+    validate(fmt.view() == "");
+
+    test_success;
+}
+
+TestResult test_negative_va_width()
+{
+    auto fmt = TRY(String::format("%*d"_sv, -4, 42));
+
+    validate(fmt.view() == "42  ");
+
+    test_success;
+}
+
+TestResult test_negative_va_precision()
+{
+    auto fmt = TRY(String::format("%.*d"_sv, -6, 0));
+
+    validate(fmt.view() == "0");
+
+    test_success;
+}
+
+TestResult test_verbatim_percent_format()
+{
+    auto fmt = TRY(String::format("%%"_sv));
+
+    validate(fmt.view() == "%");
+
+    test_success;
+}
+
 Result<void> test_main()
 {
     test_prelude;
@@ -131,10 +293,28 @@ Result<void> test_main()
     run_test(test_basic_signed_integer_format);
     run_test(test_negative_signed_integer_format);
     run_test(test_positive_signed_integer_format);
+    run_test(test_positive_signed_integer_format_with_empty_sign);
     run_test(test_format_zero_with_explicit_zero_precision);
     run_test(test_octal_format);
     run_test(test_hex_format);
     run_test(test_uppercase_hex_format);
+    run_test(test_integer_format_with_width);
+    run_test(test_zero_padded_integer_format_with_width);
+    run_test(test_integer_format_with_precision);
+    run_test(test_alternate_integer_format_with_width);
+    run_test(test_zero_padded_alternate_integer_format_with_width);
+    run_test(test_alternate_integer_format_with_precision);
+    run_test(test_integer_format_left_align);
+    run_test(test_integer_format_left_align_override_zero_pad);
+    run_test(test_integer_format_left_align_with_alternate_format);
+    run_test(test_integer_format_left_align_with_alternate_format_and_precision);
+    run_test(test_va_integer_width);
+    run_test(test_va_integer_precision);
+    run_test(test_no_precision_assumed_as_zero);
+    run_test(test_no_precision_assumed_as_explicit_zero);
+    run_test(test_negative_va_width);
+    run_test(test_negative_va_precision);
+    run_test(test_verbatim_percent_format);
 
     return {};
 }