build-anti-patterns

===SKILL:BUILD_ANTI_PATTERNS=== META: TYPE::SKILL VERSION::"1.0" PURPOSE::"Comprehensive anti-pattern catalog for build phase" SOURCE::"Extracted from anti-patterns.oct.md"

§1::ISOLATED_EDITS SYMPTOMS::"'I just changed one function' → unexpected failures in distant components" EXAMPLE::"processUser(id)→processUser(userId): 15 call sites + db query builder + GraphQL resolver = 4hrs debugging" DETECT::[ "Changes without grepping usage", "Skip dependency analysis", "Quick fix mentality", "No test failures but prod breaks" ] PREVENT::[ "Ripple map before coding (git grep usage)", "Run full test suite (not just changed file)", "Check types (mypy/tsc)", "System impact analysis" ]

§2::FEATURE_BLOAT SYMPTOMS::"'Since I'm here I'll also...' → features nobody asked for" EXAMPLE::"Task: email validation. Also adds: disposable check + DNS verify + typo suggestions = 200 lines instead of 10" DETECT::[ "Implementing not in requirements", "Adding abstractions for future", "Improving unrelated code", "Multiple concerns one commit" ] PREVENT::[ "Scope validation: explicitly requested?", "Defer until needed (Rule of Three)", "Separate PRs for improvements", "One concern per commit" ]

§3::CONTEXT_DESTRUCTION SYMPTOMS::"'Comment is obvious, removing it' → deleting architectural rationale" EXAMPLE::"setTimeout comment explaining why not setInterval → deleted → future dev reintroduces bug" DETECT::[ "Deleting non-obvious comments", "Removing TODOs without resolution", "Stripping git history", "Cleanup PRs removing context" ] PREVENT::[ "Git handles versions, comments explain WHY not WHAT", "Preserve TODOs with explanations", "Architectural decisions in docs", "Commit messages explain WHY" ]

§4::PREMATURE_OPTIMIZATION SYMPTOMS::"'This could be faster' → optimization without profiling" EXAMPLE::"Optimize array iteration while real bottleneck is N+1 database queries" DETECT::[ "Optimizing without measuring", "Assuming bottlenecks", "Complexity added for theoretical speed", "Ignoring profiler results" ] PREVENT::[ "Profile first ALWAYS", "Optimize algorithms before code (O(n²)→O(n))", "Benchmark before/after", "Complexity cost must be justified" ]

§5::TEST_PROCRASTINATION SYMPTOMS::"'I'll add tests later' → tests fit code not requirements" EXAMPLE::"Implement feature → write tests after → tests pass but feature breaks edge cases" DETECT::[ "Tests added after code", "Commit message 'Add tests'", "Single commit with both test and implementation", "Test timestamp newer than implementation" ] PREVENT::[ "TDD discipline: RED→GREEN→REFACTOR", "Git history enforcement: test commit→feat commit", "Failing test proof required", "No merge without TDD evidence" ]

§6::ABSTRACTION_ADDICTION SYMPTOMS::"'Future flexibility' → abstractions for 2 use cases" EXAMPLE::"2 similar functions → DataProcessor class with generics → only 2 call sites + complex config" DETECT::[ "Abstraction before 3rd use", "Generic solutions for specific problems", "Indirection without clarity benefit", "Flexibility nobody needs" ] PREVENT::[ "Rule of Three: 1st concrete → 2nd note → 3rd abstract", "YAGNI: You Aren't Gonna Need It", "Abstractions must reduce cognitive load", "Must be understandable without docs" ]

§7::SNOWBALL_COMMITS SYMPTOMS::"100+ files in one PR → impossible to review" EXAMPLE::"Refactor user service + add feature + fix bugs + update deps = 247 files changed" DETECT::[ "PRs with 50+ files", "Multiple unrelated changes", "Commits with mixed concerns", "Reviewer comment: 'too large to review'" ] PREVENT::[ "Atomic commits: one logical change", "Feature flags for gradual rollout", "Separate refactor from features", "Stacked PRs: small incremental" ]

§8::DEPENDENCY_DRIFT SYMPTOMS::"Outdated dependencies → security vulnerabilities + compatibility issues" EXAMPLE::"[email protected]→18.0 without testing → breaking changes in hooks" DETECT::[ "Dependencies not updated 6mo+", "Security warnings ignored", "Version pinning without reason", "No dependency audit" ] PREVENT::[ "Regular updates: monthly review", "Security scanning: npm audit, Dependabot", "Test before update: integration suite", "Document version decisions" ]