no-duplication

name	no-duplication
description	Detect and prevent all forms of duplication in RegiLattice: tweak IDs, registry ops, labels, docs, and config. Use when adding tweaks, reviewing code, auditing categories, or before committing. Triggers on: 'duplicate', 'duplication', 'same tweak', 'already exists', 'audit', 'check duplicates', 'dedup', 'overlap'.
argument-hint	What to audit: 'all', 'registry-ops', 'labels', 'ids', or a specific module name (e.g. 'Privacy', 'Office')

No-Duplication Audit — RegiLattice Skill

When to Use

• Before committing a batch of new tweaks
• After a sprint that added 10+ tweaks across multiple modules
• When a build fails with "Duplicate tweak Id" from TweakEngine.Register()
• When a test fails in TweakEngineBuiltinsTests (duplication guard tests)
• When reviewing code for duplicate registry operations or labels
• When running scripts/Audit-Duplications.ps1 to get a full picture

The 4 Duplication Types

Type	Severity	Auto-Detected By
Duplicate ID	HARD BLOCK (build error)	TweakEngine.Register() + RegisterBuiltins_AllIdsUnique test
Duplicate registry op (same PATH\ValueName by 2+ tweaks)	Warning	TweakValidator.DetectDuplicateRegistryOps() + builtins threshold test
Duplicate label (same human name in 2+ modules)	Smell	Label scan + RegisterBuiltins_NoCrossModuleLabelAndPathCollision test
Conceptual duplicate (same outcome, different code path)	Debt	Manual review + Audit-Duplications.ps1

---

Step-by-Step Audit Workflow

Step 1 — Check ID Uniqueness

# Before adding a new ID, search all modules
Select-String -Pattern '"proposed-id"' -Path src/RegiLattice.Core/Tweaks/*.cs
# Zero results = safe to use

For a batch scan of ALL duplicate IDs in the codebase:

Select-String -Path src/RegiLattice.Core/Tweaks/*.cs -Pattern 'Id = "([^"]+)"' |
    ForEach-Object { [regex]::Match($_.Line, 'Id = "([^"]+)"').Groups[1].Value } |
    Group-Object | Where-Object Count -gt 1 | Sort-Object Count -Descending |
    Select-Object Count, Name

Expected result: Empty (0 duplicate IDs). Any result here is a hard bug.

---

Step 2 — Check for Duplicate Registry Operations

Run the model-level check (exact, matches what the unit test does):

# This requires dotnet scripting or a unit test run
dotnet test tests/RegiLattice.Core.Tests --filter "DuplicateRegistryOps" --no-build --logger "console;verbosity=normal"

For a quick source-level approximation:

Select-String -Path src/RegiLattice.Core/Tweaks/*.cs -Pattern '(SetDword|SetString|SetExpandString|SetQword)\s*\(' |
    ForEach-Object {
        $m = [regex]::Match($_.Line, '@?"([^"]+)",\s*"([^"]+)"')
        if ($m.Success) { "$($m.Groups[1].Value)\$($m.Groups[2].Value)" }
    } | Group-Object | Where-Object Count -gt 1 |
    Sort-Object Count -Descending | Select-Object -First 20 Count, Name

Expected result: Ideally 0. Current known debt: ~300–800 duplicate targets exist. New additions must not increase this count — the threshold test will catch them.

---

Step 3 — Check for Duplicate Labels

Select-String -Path src/RegiLattice.Core/Tweaks/*.cs -Pattern 'Label = "([^"]+)"' |
    ForEach-Object { [regex]::Match($_.Line, 'Label = "([^"]+)"').Groups[1].Value } |
    Group-Object | Where-Object Count -gt 1 |
    Sort-Object Count -Descending | Select-Object -First 20 Count, Name

Expected result: Label collisions are acceptable ONLY if the tweaks operate through different registry paths (same feature, different mechanism). Same Label + same RegistryKeys[0] = guaranteed duplicate → must remove.

---

Step 4 — Check for Duplicate Instruction/Skill Files

# Duplicate instruction filenames (different paths, same content intent)
Get-ChildItem .github/instructions/*.md | Select-Object Name
Get-ChildItem .github/skills/**/*.md -Recurse | Select-Object Name, FullName

# Check for instruction files that cover the same topic
# (manual review — look for overlapping topics across files)

---

Step 5 — Check for Duplicate Config/Build Entries

# NuGet package references (should only appear once per PackageReference)
Select-String -Path Directory.Packages.props -Pattern 'PackageVersion' | 
    ForEach-Object { ($_ -split '"')[1] } |
    Group-Object | Where-Object Count -gt 1

# .vscode/settings.json instruction list (no file should appear twice)
Select-String -Path .vscode/settings.json -Pattern '"file":'

---

Step 6 — Run the Full Audit Script

. .\scripts\Audit-Duplications.ps1

This covers all above layers and produces a colour-coded summary report. Exit code 1 if any hard violations (duplicate IDs) are found.

---

Resolution Strategy

Removing a Functional Duplicate

1. Identify which tweak is the "original" (older creation date, or the one in the semantically correct module based on its category)
2. Keep the original; delete the copy
3. If the copy has a better description or additional ops, merge those into the original
4. Re-run dotnet build to confirm no ID collision
5. Re-run the duplication guard tests to confirm warning count decreased

Consolidating Same-Category Ops

If two tweaks in the same category write to the same registry key/value with different values:

// BEFORE (two separate tweaks — functional duplicate)
new TweakDef { Id = "priv-disable-tracking-a", ApplyOps = [RegOp.SetDword(key, "Value", 0)] }
new TweakDef { Id = "priv-disable-tracking-b", ApplyOps = [RegOp.SetDword(key, "Value", 2)] }

// AFTER (one tweak with the correct semantic value)
new TweakDef { Id = "priv-disable-tracking", ApplyOps = [RegOp.SetDword(key, "Value", 2)] }

When a Duplicate is Intentional

Add a // INTENTIONAL DUPLICATE: comment in BOTH tweaks explaining why:

new TweakDef
{
    Id = "sec-disable-wer-policy",
    Label = "Disable Windows Error Reporting",
    Category = "Security",
    // INTENTIONAL DUPLICATE: crash module also sets this; security profile needs direct control
    ApplyOps = [RegOp.SetDword(@"HKLM\SOFTWARE\Policies\...", "Disabled", 1)],
}

---

Automated Tests That Guard Against Duplication

Test	File	What It Checks
RegisterBuiltins_AllIdsUnique	TweakEngineBuiltinsTests.cs	Zero duplicate tweak IDs
RegisterBuiltins_DuplicateRegistryOps_BelowRegressionThreshold	TweakEngineBuiltinsTests.cs	Total duplicate op targets ≤ threshold
RegisterBuiltins_NoCrossModuleLabelAndPathCollision	TweakEngineBuiltinsTests.cs	No cross-category duplicate (Label + RegistryKeys[0])
RegisterBuiltins_CategorySlugs_MatchKnownPrefixes	TweakEngineBuiltinsTests.cs	ID prefixes match canonical category slugs
DetectDuplicateRegistryOps_DuplicateTarget_ReturnsWarning	TweakValidatorTests.cs	Unit test for the detection method
DetectDuplicateRegistryOps_SameTweakMultipleOps_NoWarning	TweakValidatorTests.cs	Intra-tweak ops are not false-positives
DetectDuplicateRegistryOps_NoOverlap_NoWarning	TweakValidatorTests.cs	Clean baseline returns empty
ValidateTweaks_AllBuiltins_ReturnsNoErrors	TweakEngineBuiltinsTests.cs	Full validation (IDs, labels, deps) passes