Add Encoding.Utf8WithoutBom static extension property by Copilot · Pull Request #27 · Tyrrrz/PowerKit

Copilot · 2026-04-14T17:44:42Z

Encoding.UTF8 emits a BOM, but there's no convenient analog on the Encoding type for the BOM-less variant. This adds a static extension property Utf8WithoutBom backed by new UTF8Encoding(false).

Changes

PowerKit/Extensions/EncodingExtensions.cs — new extension(Encoding) block exposing Utf8WithoutBom as a static property; instance cached in a private static field on the enclosing class
PowerKit.Tests/EncodingExtensionsTests.cs — functional test that encodes text using Utf8WithoutBom and verifies it is correctly decoded by Encoding.UTF8
PowerKit/Extensions/ZipArchiveEntryExtensions.cs — refactored to use Encoding.Utf8WithoutBom for write methods (no BOM emitted) and Encoding.UTF8 for read methods (auto-detects and strips any BOM in the content); entire class wrapped in #if NET40_OR_GREATER || NETSTANDARD || NET since ZipArchiveEntry is not available in .NET 3.5

Usage

using var writer = new StreamWriter(stream, Encoding.Utf8WithoutBom);

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Copilot

Pull request overview

Adds a convenient BOM-less UTF-8 Encoding via a static extension property, plus tests to validate its behavior, to make it easier to create StreamWriter/text output without an emitted BOM.

Changes:

Introduces Encoding.Utf8WithoutBom backed by a cached UTF8Encoding(false) instance.
Adds unit tests asserting UTF-8 identity, empty preamble (no BOM), and non-identity with Encoding.UTF8.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
PowerKit/Extensions/EncodingExtensions.cs	Adds `Encoding.Utf8WithoutBom` static extension property backed by a cached encoding instance.
PowerKit.Tests/EncodingExtensionsTests.cs	Adds tests covering web name, BOM-less preamble, and distinction from `Encoding.UTF8`.

Comments suppressed due to low confidence (1)

PowerKit.Tests/EncodingExtensionsTests.cs:26

Test method names in this repository consistently use the ..._Test suffix (and ..._Condition_Test for variants). These new tests omit the suffix, which makes the file inconsistent with the rest of the test suite; please rename the methods to match the existing naming convention.

    public void Utf8WithoutBom_Test()
    {
        // Arrange
        var text = "hello, world! 🌍";

        // Act
        var bytes = Encoding.Utf8WithoutBom.GetBytes(text);

        // Assert
        Encoding.UTF8.GetString(bytes).Should().Be(text);
    }
}

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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Tyrrrz · 2026-04-14T17:50:51Z

@copilot revert last change, there is no Encoding.ReadOnly(...)

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Copilot · 2026-04-14T17:52:14Z

@copilot revert last change, there is no Encoding.ReadOnly(...)

Reverted in 6633d98 — back to new UTF8Encoding(false) directly.

Tyrrrz · 2026-04-14T19:05:25Z

@copilot merge in latest prime and see if you can refactor some existing code with the newly added property

…-utf8withoutbom-extension Co-authored-by: Tyrrrz <1935960+Tyrrrz@users.noreply.github.com>

…tf8WithoutBom Agent-Logs-Url: https://github.com/Tyrrrz/PowerKit/sessions/4080f2c4-800e-4e10-bfb4-763d281faafc Co-authored-by: Tyrrrz <1935960+Tyrrrz@users.noreply.github.com>

Copilot · 2026-04-14T19:07:52Z

@copilot merge in latest prime and see if you can refactor some existing code with the newly added property

Done in 0f4e329. Merged prime and refactored ZipArchiveEntryExtensions — it had its own private Utf8NoBom = new UTF8Encoding(false) field that's now replaced with Encoding.Utf8WithoutBom across all 8 usages. All 133 tests pass.

Tyrrrz · 2026-04-14T19:09:46Z

@copilot

Build failing.
Do you think the read methods in ZipArchiveEntry extensions should actually use normal Encoding.UTF8 so that they can also handle conent with BOM?

…ng.UTF8 for BOM handling Agent-Logs-Url: https://github.com/Tyrrrz/PowerKit/sessions/634e2076-ae0d-4954-8810-0e0ec002275c Co-authored-by: Tyrrrz <1935960+Tyrrrz@users.noreply.github.com>

Copilot · 2026-04-14T19:12:58Z

@copilot

Build failing.
...

Fixed in 97c15d9.

Build fix: The entire ZipArchiveEntryExtensions class is now wrapped in #if NET40_OR_GREATER || NETSTANDARD || NET since ZipArchiveEntry / System.IO.Compression don't exist in net35. The inner #if that previously only guarded the async methods was redundant and is removed.
Read vs write encoding: Yes — read methods now default to Encoding.UTF8, which causes StreamReader to auto-detect and strip any BOM present in the content. Write methods keep Encoding.Utf8WithoutBom so no BOM is ever emitted.

Copilot AI and others added 2 commits April 14, 2026 17:31

feat: add Encoding.Utf8WithoutBom extension

6a97b1a

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test: fix test method naming consistency

70d4ecb

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Copilot AI assigned Copilot and Tyrrrz Apr 14, 2026

Copilot created this pull request from a session on behalf of Tyrrrz April 14, 2026 17:44 View session

Tyrrrz added the enhancement New feature or request label Apr 14, 2026

Tyrrrz marked this pull request as ready for review April 14, 2026 17:44

Copilot AI review requested due to automatic review settings April 14, 2026 17:44

Copilot started reviewing on behalf of Tyrrrz April 14, 2026 17:45 View session

Tyrrrz reviewed Apr 14, 2026

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Comment thread PowerKit.Tests/EncodingExtensionsTests.cs

Copilot started work on behalf of Tyrrrz April 14, 2026 17:45 View session

Tyrrrz and others added 2 commits April 14, 2026 20:46

Update EncodingExtensions.cs

f1612c0

test: replace property checks with functional encoding/decoding test

16af99f

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Copilot finished work on behalf of Tyrrrz April 14, 2026 17:47

Copilot AI requested a review from Tyrrrz April 14, 2026 17:47

Copilot AI reviewed Apr 14, 2026

View reviewed changes

Comment thread PowerKit/Extensions/EncodingExtensions.cs

Update PowerKit/Extensions/EncodingExtensions.cs

210164c

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Copilot started work on behalf of Tyrrrz April 14, 2026 17:50 View session

revert: remove Encoding.ReadOnly() wrapper (method doesn't exist)

6633d98

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Copilot finished work on behalf of Tyrrrz April 14, 2026 17:52

Copilot started work on behalf of Tyrrrz April 14, 2026 19:05 View session

Copilot AI and others added 2 commits April 14, 2026 19:07

Merge remote-tracking branch 'origin/prime' into copilot/add-encoding…

0cb2107

…-utf8withoutbom-extension Co-authored-by: Tyrrrz <1935960+Tyrrrz@users.noreply.github.com>

Copilot finished work on behalf of Tyrrrz April 14, 2026 19:09

Copilot started work on behalf of Tyrrrz April 14, 2026 19:09 View session

Copilot finished work on behalf of Tyrrrz April 14, 2026 19:13

Update ZipArchiveEntryExtensions.cs

6a80d70

Tyrrrz merged commit b798fbc into prime Apr 14, 2026
7 checks passed

Tyrrrz deleted the copilot/add-encoding-utf8withoutbom-extension branch April 14, 2026 19:18

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Add Encoding.Utf8WithoutBom static extension property#27

Add Encoding.Utf8WithoutBom static extension property#27
Tyrrrz merged 10 commits intoprimefrom
copilot/add-encoding-utf8withoutbom-extension

Copilot AI commented Apr 14, 2026 •

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Pull request overview

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Copilot AI commented Apr 14, 2026 •

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