fix(reset): reset deleted profile settings the user set by hand, and reported success

[fcreme]

Found by an adversarial audit (0 of 3 verifiers refuted), then reproduced against the real module before fixing.

The bug

Reset-StyleDirect stripped every name in $script:TStylesThemeFields present on the target profile, with no record of which of them TerminalStyles actually wrote:

foreach ($field in $script:TStylesThemeFields) {
    if ($entry.PSObject.Properties.Match($field).Count) {
        $entry.PSObject.Properties.Remove($field)
    }
}

That list is colorScheme, tabTitle, tabColor, cursorShape, useAcrylic, opacity, experimental.retroTerminalEffect, font, padding plus the four backgroundImage* keys — very nearly everything a user configures through the Windows Terminal settings UI.

Failure scenario. A user sets acrylic, opacity 60, padding, a bar cursor, Consolas 14, their own wallpaper and a tab title on their PowerShell profile. They never apply a style to it. They run tstyles reset -Target 'PowerShell' out of curiosity. All eight keys are deleted, and the command prints Reset 'PowerShell' to its unstyled default. in green. Only name, guid and unlisted keys survive.

README.md:222 has promised the opposite since it was written:

settings.json.bak first. Fields you set on the profile by hand are left alone.

The asymmetry is the tell: the apply path already refuses the symmetric thing. Test-ManagedBackgroundPath exists precisely so a background the user set is not cleared by a style that ships none — the 'skip' arm in Merge-StyleIntoSettings is this exact question, asked. Reset never asked it.

The fix

Reset now requires the profile to carry a colorScheme naming a style this tool knows. An apply always writes that key and writes it last, so there is no way to be styled by TerminalStyles and not carry it. A profile without one is one we never touched — the honest answer is to change nothing and say so, rather than guess at provenance.

A second defect on the same path, fixed by ordering

The check runs before Save-SettingsBackup. A reset that changed nothing previously still:

• rolled settings.json.bak over, spending the user's only undo of their last real apply; and
• rewrote settings.json, re-serialising the parsed object and dropping every JSONC comment in it.

The likeliest way a curious user tried this command was also the way that cost them their comments.

Tests

The existing test asserted only that schemes[] survived a reset of a profile with no colorScheme — so the field destruction on that exact fixture went unnoticed. Now:

• nothing is written at all for a profile with no colorScheme;
• hand-set fields survive byte-for-byte on disk (useAcrylic, wallpaper.png, cursorShape all still present);
• the other direction — a profile whose colorScheme names a real style still resets fully, so the guard cannot quietly disable the feature.

Mutation-checked: reverting the guard turns the first two red.

Verification

1428 passed, 0 failed.

Scope note

This is Windows-only in effect (there is no settings.json off Windows Terminal), which is why it survived — the project is developed on a Mac.

🤖 Generated with Claude Code

https://claude.ai/code/session_01Fc4mE7gSHoux5wL6VEo59S