ModernUO/Projects/Server.Tests/Tests/Buffers/RawInterpolatedStringHandlerTests.cs
Kamron Batman 679e66b99d
feat(buffers): add :L lowercase format spec to RawInterpolatedStringHandler (#2440)
## Summary

Adds a custom `:L` format specifier to `RawInterpolatedStringHandler`. When the format string is `"L"`, the handler lowercases the formatted value's chars in-place after the underlying `ISpanFormattable.TryFormat` / `IFormattable.ToString` path completes. Zero allocation, single-pass.

## Usage

```csharp
mob.SendMessage($"You earned a {rank:L} trophy!");           // "gold"
mob.SendMessage($"Welcome, {playerName:L}");                  // lowercased
mob.SendMessage($"{count:L} kills");                          // ints unchanged ("42")
```

## Motivation

Eliminates the `value.ToString().ToLowerInvariant()` two-allocation idiom that appears across the codebase for any type that goes through an interpolation handler. After this lands, content code can use the `:L` specifier directly instead of helper extensions or per-enum lookup tables.

## Coverage

- `AppendFormatted<T>(T value, string? format)` — generic path (covers IFormattable, ISpanFormattable, .ToString fallback)
- `AppendFormatted(ReadOnlySpan<char> value, int alignment, string? format)` — span path with alignment-aware lowercase range (only the value range is lowercased, not padding)
- `AppendFormatted<T>(T value, int alignment, string? format)` and `AppendFormatted(string? value, int alignment, string? format)` and `AppendFormatted(object? value, int alignment, string? format)` — inherit via delegation

The `format == "L"` comparison is case-sensitive — `:l` (lowercase L) is NOT recognized. `:L` matches the convention of e.g. `:N0` / `:F2` (numeric format specifiers traditionally use uppercase). `char.ToLowerInvariant` is used (not locale-dependent) for predictable game text.

## Future cleanup

Phase 3.3 (#2438) introduced a per-enum `TrophyRank.LowerName()` extension to eliminate `rank.ToString().ToLower()` allocations at 10 ConPVP sites. Once this PR lands, those sites can be simplified to `{rank:L}` and the `TrophyRankExtensions` helper can be removed. Tracked as a follow-up.
2026-05-03 18:24:57 -07:00

95 lines
3.3 KiB
C#

using System;
using Server.Buffers;
using Xunit;
namespace Server.Tests.Buffers;
public class RawInterpolatedStringHandlerTests
{
[Fact]
public void TestLowercaseFormatString()
{
var name = "Hello WORLD";
var handler = new RawInterpolatedStringHandler(0, 1);
handler.AppendFormatted(name, format: "L");
Assert.Equal("hello world", handler.Text.ToString());
handler.Clear();
}
[Fact]
public void TestLowercaseFormatEnum()
{
var handler = new RawInterpolatedStringHandler(0, 1);
handler.AppendFormatted(DayOfWeek.Wednesday, format: "L");
Assert.Equal("wednesday", handler.Text.ToString());
handler.Clear();
}
[Fact]
public void TestLowercaseFormatInt()
{
// Numerics have no uppercase chars; :L should be a no-op
var handler = new RawInterpolatedStringHandler(0, 1);
handler.AppendFormatted(42, format: "L");
Assert.Equal("42", handler.Text.ToString());
handler.Clear();
}
[Fact]
public void TestLowercaseFormatSpan()
{
var span = "MIXED Case TEXT".AsSpan();
var handler = new RawInterpolatedStringHandler(0, 1);
handler.AppendFormatted(span, alignment: 0, format: "L");
Assert.Equal("mixed case text", handler.Text.ToString());
handler.Clear();
}
[Fact]
public void TestLowercaseFormatWithAlignment()
{
// Right-aligned: "Gold" in width 8 with :L -> " gold"
var handler = new RawInterpolatedStringHandler(0, 1);
handler.AppendFormatted("Gold", alignment: 8, format: "L");
Assert.Equal(" gold", handler.Text.ToString());
handler.Clear();
}
[Fact]
public void TestNoFormatPreservesCase()
{
var handler = new RawInterpolatedStringHandler(0, 1);
handler.AppendFormatted("Hello WORLD");
Assert.Equal("Hello WORLD", handler.Text.ToString());
handler.Clear();
}
[Fact]
public void TestUnicodeLowercase()
{
// ToLowerInvariant on Greek letter
var handler = new RawInterpolatedStringHandler(0, 1);
handler.AppendFormatted("ΑΒΓ", format: "L");
Assert.Equal("αβγ", handler.Text.ToString());
handler.Clear();
}
[Fact]
public void TestLowercaseFormatSurrogatePairAtChunkBoundary()
{
// The chunked lowercase path uses a 256-char stackalloc temp buffer. Place a
// supplementary-plane code point (U+10400 DESERET CAPITAL LONG I, encoded as
// surrogate pair "𐐀") so its high half lands at offset 255 and its
// low half at offset 256 — straddling the chunk boundary. Without the
// surrogate-aware boundary trim, ToLowerInvariant would see two lone surrogates
// and pass them through unchanged, leaving the capital code point intact.
// With the trim, the chunk shrinks to 255 chars and the pair stays together
// in the next chunk, lowercasing correctly to U+10428 ("𐐨").
var input = new string('a', 255) + "𐐀" + new string('b', 10);
var handler = new RawInterpolatedStringHandler(0, 1);
handler.AppendFormatted(input, format: "L");
var expected = new string('a', 255) + "𐐨" + new string('b', 10);
Assert.Equal(expected, handler.Text.ToString());
handler.Clear();
}
}