Hosts: add “No leading spaces” option and honor it when saving

[mohammed-saalim]

Summary of the Pull Request

Adds a new Hosts File Editor setting “No leading spaces” that prevents prepending spaces to active lines when saving the hosts file (when any entry is disabled). Default is Off to preserve current behavior.

PR Checklist

• Closes: Hosts File Editor: Adds no whitespace option #36386  

• Communication: N/A (small, scoped option)

• Tests: Added/updated and all pass

• Localization: New en-US strings added; other locales handled by loc pipeline

• Dev docs: N/A

• New binaries: None

• Documentation updated: N/A

Detailed Description of the Pull Request / Additional comments

• Settings surface:

  - src/settings-ui/Settings.UI.Library/HostsProperties.cs: add NoLeadingSpaces

  - src/modules/Hosts/HostsUILib/Settings/IUserSettings.cs: add NoLeadingSpaces

  - src/modules/Hosts/Hosts/Settings/UserSettings.cs: load/save value from settings.json

  - src/settings-ui/Settings.UI/ViewModels/HostsViewModel.cs: expose NoLeadingSpaces

  - src/settings-ui/Settings.UI/SettingsXAML/Views/HostsPage.xaml: new SettingsCard toggle

  - src/settings-ui/Settings.UI/Strings/en-us/Resources.resw: add Hosts_NoLeadingSpaces.Header/Description

• Writer change:

  - src/modules/Hosts/HostsUILib/Helpers/HostsService.cs: gate indent with anyDisabled && !_userSettings.NoLeadingSpaces

• Tests:

  - src/modules/Hosts/Hosts.Tests/HostsServiceTest.cs: NoLeadingSpaces_Disabled_RemovesIndent

Backward compatibility: default Off, current formatting unchanged unless the user enables the option.

Validation Steps Performed

• Automated: HostsEditor.UnitTests including NoLeadingSpaces_Disabled_RemovesIndent passing.

• Manual:

  1. Run PowerToys (runner) as Admin.

  2. Settings → Hosts File Editor → enable “No leading spaces”.

  3. In editor, add active 127.0.0.10 example1 and disabled 127.0.0.11 example2; Save.

  4. Open C:\Windows\System32\drivers\etc\hosts in Notepad.

     - ON: active line starts at column 0; disabled is # 127....

     - OFF: active line begins with two spaces when a disabled entry exists.

[yeelam-gordon]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[yeelam-gordon]

@davidegiacometti, I assume originally adding space is for helping Human visual alignment for those IPs.
@mohammed-saalim , I assume you want this one because of "parser"? (i.e. not because of human), and probably even it is an existing parser code you CANNOT change already? (Since trim for heading space usually simple)

[mohammed-saalim]

@yeelam-gordon Thanks! Yes, the original two-space indent looks intended for visual alignment. The motivation for this option is parser/tooling compatibility, not human readability. Some consumers expect the IP to start at column 0 and fail or behave unexpectedly when there are leading spaces. Example: squid and a few strict scripts that anchor on ^\d. The Windows sample header even says “The IP address should be placed in the first column”.

Trimming in our own parser wouldn’t help these external tools because they read the file as-is. This PR doesn’t change the default behavior (alignment remains the default); it only adds an opt‑in switch to write active entries without the extra leading spaces when a disabled entry exists. Comments and all other spacing remain unchanged. Before/after:

• With option ON:

  127.0.0.10 example1
  # 127.0.0.11 example2
  

• With option OFF (current behavior):

    127.0.0.10 example1
  # 127.0.0.11 example2
  

A unit test (NoLeadingSpaces_Disabled_RemovesIndent) validates the write path.

[davidegiacometti]

@davidegiacometti, I assume originally adding space is for helping Human visual alignment for those IPs.

Hi, that's correct!

[Copilot]

Pull Request Overview

This PR adds a new "No leading spaces" option to the Hosts File Editor that prevents prepending spaces to active lines when saving the hosts file. The feature addresses formatting preferences where users want active entries to start at column 0 instead of being indented when disabled entries exist.

• Adds a new boolean setting NoLeadingSpaces with default value false to preserve current behavior
• Modifies the hosts file writing logic to conditionally apply leading spaces based on the new setting
• Includes comprehensive UI integration and test coverage for the new functionality

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
HostsProperties.cs	Adds NoLeadingSpaces property with default false value
IUserSettings.cs	Extends interface to include NoLeadingSpaces property
UserSettings.cs	Implements NoLeadingSpaces property loading from settings
HostsViewModel.cs	Exposes NoLeadingSpaces property for UI binding
HostsPage.xaml	Adds toggle switch UI control for the new setting
Resources.resw	Adds localization strings for the new setting
HostsService.cs	Modifies write logic to honor NoLeadingSpaces setting
HostsServiceTest.cs	Adds unit test to verify NoLeadingSpaces functionality

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