de-sloppify（去马虎）

De-Sloppify

Core Principles

1. Systematic over random — Follow the cleanup pipeline in order. Formatting first (because it touches every file), dead code last (because earlier steps might reveal it). Random cleanup misses things and creates merge conflicts.
2. Verify after each step — Run dotnet build and dotnet test after every step. A cleanup that breaks something is worse than the mess it was fixing. Never batch multiple cleanup types into one untested change.
3. Safe removals only — Before removing any code flagged as "dead," verify it isn't used via reflection, DI conventions, or serialization. find_references shows compile-time usage; grep for string-based references that Roslyn cannot track.
4. One concern at a time — Don't mix formatting fixes with logic changes. Don't combine dead code removal with new feature work. Separate concerns make code review possible and reverts safe.
5. Commit between phases — Each cleanup step gets its own commit. If Step 4 (dead code removal) breaks something, revert just that commit without losing the formatting and analyzer fixes from Steps 1-3.

Patterns

7-Step Cleanup Pipeline

Execute in order. Verify (build + test) after each step. Commit each step separately.

Step 1: Format All Code

dotnet format

Why first: Formatting touches many files. Getting it out of the way prevents merge conflicts with subsequent steps. After this step, every file has consistent style.

Verify: dotnet format --verify-no-changes should report no changes. Commit: chore: apply dotnet format

Step 2: Remove Unused Usings

dotnet format analyzers --diagnostics IDE0005

Why second: Unused usings are noise. Removing them makes subsequent analysis cleaner and reduces false positives in code review.

Verify: dotnet build should show no new errors. Run dotnet test if usings removal is extensive. Commit: chore: remove unused using statements

Step 3: Fix Analyzer Warnings

MCP: get_diagnostics(scope: "solution", severityFilter: "warning")

Triage warnings by category:

• Nullability warnings (CS8600-CS8604) — Add null checks or use the null-forgiving operator with a comment explaining why null is impossible.
• Unused variables (CS0219) — Remove them.
• Obsolete API usage (CS0618) — Migrate to the recommended replacement.
• IDE suggestions (IDE0xxx) — Apply if they improve readability.

Fix in priority order: compiler warnings first, then analyzer suggestions. Verify: dotnet build with zero new warnings. dotnet test passes. Commit: chore: fix analyzer warnings

Step 4: Remove Dead Code

MCP: find_dead_code(scope: "solution", kind: "all")

For each result, perform a safety check before removing:

SAFETY CHECK BEFORE REMOVAL:
1. find_references(symbolName: "DeadType") — confirm zero compile-time references
2. Grep for string-based usage:
   - "nameof(DeadType)" — sometimes used in attributes or logging
   - Reflection: Type.GetType("DeadType"), Activator.CreateInstance
   - DI registration: services.AddScoped(typeof(IHandler<>), typeof(DeadType))
   - Serialization: [JsonDerivedType(typeof(DeadType))]
3. Check if it's a public API consumed by external packages
4. Check if it's referenced in configuration files (appsettings.json, etc.)

ONLY remove if all checks come back clean.

Verify: dotnet build and dotnet test pass. Commit: chore: remove dead code

Step 5: Resolve TODOs

# Find all TODOs in the codebase
grep -rn "TODO\|HACK\|FIXME\|XXX" --include="*.cs"

For each TODO, decide:

• Fix it now — If it's small and self-contained, resolve it in this cleanup pass.
• Create an issue — If it requires significant work, create a GitHub issue and update the TODO with the issue number: // TODO(#142): Implement retry logic
• Remove it — If it's stale (the work was already done or is no longer relevant), delete the comment.

Verify: dotnet build and dotnet test pass. Commit: chore: resolve TODO comments

Step 6: Seal Non-Inherited Classes

MCP: find_dead_code(scope: "solution", kind: "type") — for a list of types
MCP: get_type_hierarchy(typeName: "EachClass") — check for derived types

Add sealed to every class that:

• Has no derived types (confirmed via get_type_hierarchy)
• Is not a base class by design (no virtual or abstract members)
• Is not used as an open generic in DI registration
• Is not a test fixture base class

Why seal: Sealed classes enable compiler optimizations (devirtualization), communicate design intent ("this class is not meant to be extended"), and prevent accidental inheritance.

// BEFORE
public class OrderValidator : AbstractValidator<CreateOrderCommand>
{
    public OrderValidator()
    {
        RuleFor(x => x.CustomerId).NotEmpty();
    }
}

// AFTER — sealed, because nothing inherits from it
public sealed class OrderValidator : AbstractValidator<CreateOrderCommand>
{
    public OrderValidator()
    {
        RuleFor(x => x.CustomerId).NotEmpty();
    }
}

Skip sealing:

• Classes with virtual members designed for override
• Classes used as IClassFixture<T> in tests (xUnit requires non-sealed)
• Base classes in a hierarchy (Entity<T>, AggregateRoot, etc.)

Verify: dotnet build and dotnet test pass. Commit: chore: seal non-inherited classes

Step 7: Propagate CancellationToken

MCP: detect_antipatterns(severity: "warning") — filter for "missing CancellationToken"

Trace the async call chain from entry points (endpoints, handlers) through services to data access (DbContext, HttpClient). Ensure CancellationToken flows through every layer.

// BEFORE — CancellationToken stops at the endpoint
app.MapGet("/orders/{id}", async (Guid id, AppDbContext db) =>
{
    var order = await db.Orders.FindAsync(id);
    return order is not null ? Results.Ok(order) : Results.NotFound();
});

// AFTER — CancellationToken propagated to EF Core
app.MapGet("/orders/{id}", async (Guid id, AppDbContext db, CancellationToken ct) =>
{
    var order = await db.Orders.FindAsync([id], ct);
    return order is not null ? Results.Ok(order) : Results.NotFound();
});

Common propagation points:

• Minimal API endpoints: add CancellationToken ct parameter (auto-bound by ASP.NET Core)
• Mediator/MediatR handlers: already provided in Handle(TRequest, CancellationToken)
• EF Core: SaveChangesAsync(ct), ToListAsync(ct), FindAsync([key], ct)
• HttpClient: GetAsync(url, ct), PostAsync(url, content, ct)

Verify: dotnet build and dotnet test pass. Commit: chore: propagate CancellationToken through async chains

Cleanup Summary Report

After completing all steps, produce a summary:

## De-Sloppify Report

| Step | Changes | Files Affected |
|------|---------|----------------|
| 1. Format | Applied consistent formatting | 23 files |
| 2. Usings | Removed 47 unused usings | 18 files |
| 3. Analyzers | Fixed 12 warnings (8 nullability, 3 unused vars, 1 obsolete) | 9 files |
| 4. Dead Code | Removed 3 unused types, 5 unused methods | 6 files |
| 5. TODOs | Fixed 2, created issues for 3, removed 1 stale | 5 files |
| 6. Sealed | Sealed 14 classes | 14 files |
| 7. CancellationToken | Added propagation to 8 async chains | 11 files |

**Total: 7 commits, 86 files improved**

Anti-patterns

Mixing Cleanup with Feature Work

# BAD — one commit with formatting + new feature + dead code removal
git commit -m "Add order validation and clean up code"
# Impossible to review, impossible to revert the cleanup without losing the feature

# GOOD — separate commits, separate concerns
git commit -m "chore: apply dotnet format"
git commit -m "chore: remove dead code"
git commit -m "feat: add order validation"

Removing Code Without Checking Reflection

# BAD — find_dead_code says it's unused, so delete it
MCP: find_dead_code → "PaymentProcessor has 0 references"
*Deletes PaymentProcessor*
# Runtime crash: DI container can't resolve IPaymentProcessor
# It was registered via: services.AddScoped(typeof(IPaymentProcessor), typeof(PaymentProcessor))

# GOOD — safety check before removal
MCP: find_dead_code → "PaymentProcessor has 0 references"
MCP: find_references(symbolName: "PaymentProcessor") → 0 compile-time refs
Grep: "PaymentProcessor" in *.cs, *.json → Found in DI registration
*Keep PaymentProcessor — it's used via DI convention*

Sealing Classes That Tests Mock

# BAD — sealing a class that tests inherit from
public sealed class OrderService { ... }
// Test project: class MockOrderService : OrderService { ... } — COMPILE ERROR

# GOOD — check for test doubles before sealing
MCP: get_type_hierarchy(typeName: "OrderService") → no derived types in production
Grep: "OrderService" in test projects → no inheritance, only usage via interface
*Safe to seal — tests use IOrderService, not OrderService directly*

Batch-Committing All Cleanup

# BAD — one giant commit with all 7 steps
git add -A && git commit -m "chore: cleanup everything"
# If sealing a class broke a test, you have to revert ALL cleanup to fix it

# GOOD — commit per step with verification between
Step 1 → verify → commit
Step 2 → verify → commit
...
# If Step 6 (sealed) breaks something, revert only that commit

Running Cleanup Without Tests

# BAD — "it's just formatting and dead code, what could go wrong?"
dotnet format → commit (no test run)
Remove dead code → commit (no test run)
# Dead code was actually used by a test helper via reflection — tests broken

# GOOD — verify after every step
dotnet format → dotnet test → commit
Remove dead code → dotnet test → commit

Decision Guide