{ "policy": { "version": 5, "patterns": { "version": 1, "method": "CURATED_PRACTICE_TOPIC", "notice": "Pattern topics identify design choices to practice. Read the ticket's acceptance criteria and justify the simplest suitable approach. Tags are not capability or ownership evidence; an untagged ticket has no curated pattern topic assigned." }, "fieldMix": { "version": 1, "method": "CURATED_ESTIMATE", "notice": "Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence." }, "contentStatus": "PRACTICE_BRIEF", "assessmentStatus": "NOT_QUALIFIED", "evidenceUse": "NONE", "aiPolicy": "AI tools are welcome during implementation. Record assumptions, review the result, and verify its behavior.", "notice": "Fictional engineering practice briefs. Starter repositories, fixtures, automated grading, and verified ownership are not included.", "outcomeEvidence": "Tests, patches, and runbooks are requested deliverables. They become Outcome Evidence only through a qualified Mission and immutable Evidence IDs.", "ownershipEvidence": "Independent adaptation must be observed under a declared verification policy and cite immutable Evidence IDs. Completing a planning ticket establishes no Ownership Evidence." }, "patternTopics": [ { "id": "factory-method", "label": "Factory Method", "group": "Creational" }, { "id": "abstract-factory", "label": "Abstract Factory", "group": "Creational" }, { "id": "builder", "label": "Builder", "group": "Creational" }, { "id": "prototype", "label": "Prototype", "group": "Creational" }, { "id": "singleton", "label": "Singleton", "group": "Creational" }, { "id": "adapter", "label": "Adapter", "group": "Structural" }, { "id": "bridge", "label": "Bridge", "group": "Structural" }, { "id": "composite", "label": "Composite", "group": "Structural" }, { "id": "decorator", "label": "Decorator", "group": "Structural" }, { "id": "facade", "label": "Facade", "group": "Structural" }, { "id": "flyweight", "label": "Flyweight", "group": "Structural" }, { "id": "proxy", "label": "Proxy", "group": "Structural" }, { "id": "chain-of-responsibility", "label": "Chain of Responsibility", "group": "Behavioral" }, { "id": "command", "label": "Command", "group": "Behavioral" }, { "id": "interpreter", "label": "Interpreter", "group": "Behavioral" }, { "id": "iterator", "label": "Iterator", "group": "Behavioral" }, { "id": "mediator", "label": "Mediator", "group": "Behavioral" }, { "id": "memento", "label": "Memento", "group": "Behavioral" }, { "id": "observer", "label": "Observer", "group": "Behavioral" }, { "id": "state", "label": "State", "group": "Behavioral" }, { "id": "strategy", "label": "Strategy", "group": "Behavioral" }, { "id": "template-method", "label": "Template Method", "group": "Behavioral" }, { "id": "visitor", "label": "Visitor", "group": "Behavioral" }, { "id": "ports-and-adapters", "label": "Ports and Adapters", "group": "Architectural" }, { "id": "cqrs", "label": "CQRS", "group": "Architectural" }, { "id": "strangler-fig", "label": "Strangler Fig", "group": "Architectural" }, { "id": "saga", "label": "Saga", "group": "Distributed and reliability" }, { "id": "transactional-outbox", "label": "Transactional Outbox", "group": "Distributed and reliability" }, { "id": "circuit-breaker", "label": "Circuit Breaker", "group": "Distributed and reliability" }, { "id": "bulkhead", "label": "Bulkhead", "group": "Distributed and reliability" } ], "projects": [ { "id": "d50423a2-7db9-42a2-aae5-55e8c83682ad", "key": "CTYPE", "title": "A small expression type checker with explainable errors", "field": "Compiler and language tooling", "summary": "Type-check a bounded expression language without evaluating submitted expressions.", "context": "Fictional rules editor Willow supports numbers, strings, booleans, records and functions in a deliberately small language. Define syntax and type rules locally; no arbitrary code execution is needed.", "stack": [ "TypeScript", "Vitest", "Typed AST fixtures" ], "prerequisites": [ "Create synthetic AST fixtures and a written type-rule table.", "Define source spans and structured diagnostic output." ], "developerValue": "Practice type environments, unification and explainable rejection.", "companyValue": "Inspect whether developer tooling catches mistakes without hiding uncertainty.", "delivery": "Limit scope to the declared type system; general language compatibility is not claimed.", "phases": [ { "id": "rules", "title": "Establish type rules", "goal": "Handle literals and lexical scope." }, { "id": "inference", "title": "Resolve expression types", "goal": "Explain composition failures." }, { "id": "stability", "title": "Keep checking predictable", "goal": "Bound work and stabilize diagnostics." } ], "tickets": [ { "id": "1ed460c9-579f-466a-9a61-0fedf63492c6", "key": "CTYPE-101", "title": "Assign explicit types to rules-editor literals", "type": "TASK", "priority": "MEDIUM", "difficulty": "FOUNDATIONAL", "estimateMinutes": 60, "phaseId": "rules", "dependsOn": [], "scenario": "The prototype infers booleans from string truthiness. Type literals from AST node kinds only.", "acceptanceCriteria": [ "Number string and boolean types differ", "Empty string stays string", "Unknown literal kind fails explicitly" ], "implementationNotes": [ "Do not evaluate literal source text." ], "verification": [ "Check each supported literal", "Reject unsupported node kind" ], "deliverables": [ "Literal checker and cases" ], "rollout": "Reject unknown nodes while supported literals remain available.", "skills": [ "Type systems", "AST" ], "fieldMix": [ { "field": "Compiler and language tooling", "percentage": 100 } ], "patterns": [] }, { "id": "f8e9ba70-b675-448b-a83b-3abc1c0b564f", "key": "CTYPE-102", "title": "Resolve expression identifiers through lexical scope", "type": "BUG", "priority": "HIGH", "difficulty": "INTERMEDIATE", "estimateMinutes": 120, "phaseId": "rules", "dependsOn": [ "CTYPE-101" ], "scenario": "Inner bindings overwrite the global environment and leak into sibling expressions. Use scoped environments.", "acceptanceCriteria": [ "Inner shadowing is local", "Sibling scope remains unchanged", "Unbound names include source location" ], "implementationNotes": [ "Environments must not mutate parent bindings accidentally." ], "verification": [ "Check nested shadowing", "Use name outside its scope" ], "deliverables": [ "Scope resolver and cases" ], "rollout": "Disable nested bindings if scope isolation fails.", "skills": [ "Scoping", "Type checking" ], "fieldMix": [ { "field": "Compiler and language tooling", "percentage": 100 } ], "patterns": [] }, { "id": "34ce6bc2-e2b9-4efe-bb3c-ca839ad4c016", "key": "CTYPE-103", "title": "Explain rules-editor operator operand mismatches", "type": "STORY", "priority": "MEDIUM", "difficulty": "FOUNDATIONAL", "estimateMinutes": 90, "phaseId": "rules", "dependsOn": [ "CTYPE-101", "CTYPE-102" ], "scenario": "Invalid addition reports Type error without naming either operand type. Add structured expected and actual types.", "acceptanceCriteria": [ "Valid operands infer result", "Mismatch identifies operator span", "Diagnostic includes both operand types" ], "implementationNotes": [ "Keep wording independent from internal object serialization." ], "verification": [ "Add two numeric literals", "Add number to unsupported record" ], "deliverables": [ "Operator rules and diagnostic cases" ], "rollout": "Reject ambiguous operators with explicit unsupported message.", "skills": [ "Diagnostics", "Type rules" ], "fieldMix": [ { "field": "Compiler and language tooling", "percentage": 100 } ], "patterns": [] }, { "id": "8da7966d-9134-47d4-a6b1-5fdc5251e93c", "key": "CTYPE-104", "title": "Check function calls for arity before argument inference", "type": "TASK", "priority": "MEDIUM", "difficulty": "INTERMEDIATE", "estimateMinutes": 135, "phaseId": "inference", "dependsOn": [ "CTYPE-102", "CTYPE-103" ], "scenario": "Calling a two-argument function with one argument crashes inference. Validate arity and check only supplied expressions safely.", "acceptanceCriteria": [ "Correct arity checks all arguments", "Wrong arity reports counts", "Nested argument errors remain inspectable" ], "implementationNotes": [ "Avoid fabricating missing AST nodes." ], "verification": [ "Check valid call", "Call with too few and too many arguments" ], "deliverables": [ "Call checker and arity cases" ], "rollout": "Disable call inference for malformed ASTs.", "skills": [ "Type checking", "Validation" ], "fieldMix": [ { "field": "Compiler and language tooling", "percentage": 100 } ], "patterns": [] }, { "id": "b35388eb-5588-4bf1-93fb-147dda14fd63", "key": "CTYPE-105", "title": "Unify rules-editor type variables with an occurs check", "type": "BUG", "priority": "HIGH", "difficulty": "EXPERT", "estimateMinutes": 240, "phaseId": "inference", "dependsOn": [ "CTYPE-104" ], "scenario": "A recursive synthetic constraint produces an infinite inferred type. Reject self-containing substitutions.", "acceptanceCriteria": [ "Acyclic constraints unify", "Recursive substitution fails with reason", "Failure does not corrupt remaining environment" ], "implementationNotes": [ "Bound this ticket to monomorphic variable unification." ], "verification": [ "Unify variable with number", "Attempt variable equal to function containing itself" ], "deliverables": [ "Unifier and occurs-check cases" ], "rollout": "Disable variable inference if substitution integrity fails.", "skills": [ "Unification", "Algorithms" ], "fieldMix": [ { "field": "Compiler and language tooling", "percentage": 100 } ], "patterns": [] }, { "id": "6f28bdd8-7ead-43d7-8d19-98e7d9fb1159", "key": "CTYPE-106", "title": "Report missing rules-editor record fields without losing known fields", "type": "STORY", "priority": "MEDIUM", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "inference", "dependsOn": [ "CTYPE-103", "CTYPE-105" ], "scenario": "Reading an absent field turns the whole record into unknown and suppresses later valid diagnostics. Preserve field-level information.", "acceptanceCriteria": [ "Existing field returns declared type", "Missing field names available keys within a cap", "Later checks retain known types" ], "implementationNotes": [ "Do not expose arbitrary source values in diagnostics." ], "verification": [ "Access known field", "Access absent field then known field" ], "deliverables": [ "Record-access rule and recovery cases" ], "rollout": "Reject absent-field expression only while preserving surrounding scope.", "skills": [ "Type systems", "Error recovery" ], "fieldMix": [ { "field": "Compiler and language tooling", "percentage": 100 } ], "patterns": [] }, { "id": "10f9529a-4608-474e-ae6f-ebbc05d16e19", "key": "CTYPE-107", "title": "Merge rules-editor branch types through explicit compatibility rules", "type": "TASK", "priority": "HIGH", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "inference", "dependsOn": [ "CTYPE-105", "CTYPE-106" ], "scenario": "Conditional branches return incompatible values but the checker chooses the first branch type. Define their common result rule.", "acceptanceCriteria": [ "Compatible branches infer documented type", "Incompatible branches report both spans", "Condition must be boolean" ], "implementationNotes": [ "Do not introduce implicit coercion without a declared rule." ], "verification": [ "Check matching branches", "Check number versus record branches" ], "deliverables": [ "Conditional rule and compatibility cases" ], "rollout": "Reject mixed branches until the rule is stable.", "skills": [ "Type inference", "Control flow" ], "fieldMix": [ { "field": "Compiler and language tooling", "percentage": 100 } ], "patterns": [] }, { "id": "b91ba8bf-6445-452f-a499-c24ae8a3a001", "key": "CTYPE-108", "title": "Make rules-editor diagnostics deterministic across map insertion order", "type": "BUG", "priority": "MEDIUM", "difficulty": "INTERMEDIATE", "estimateMinutes": 120, "phaseId": "stability", "dependsOn": [ "CTYPE-106", "CTYPE-107" ], "scenario": "Equivalent AST construction order changes diagnostic output and noisy snapshots. Sort by source and stable category.", "acceptanceCriteria": [ "Equivalent inputs yield same order", "Related locations stay attached", "Equal-span tie-breaking is documented" ], "implementationNotes": [ "Determinism must not remove distinct failures." ], "verification": [ "Reorder environment construction", "Create two same-span categories" ], "deliverables": [ "Diagnostic ordering and cases" ], "rollout": "Preserve stable source traversal if sorting loses relationships.", "skills": [ "Determinism", "Diagnostics" ], "fieldMix": [ { "field": "Compiler and language tooling", "percentage": 100 } ], "patterns": [] }, { "id": "8963cb6c-1945-444e-a308-210ef64c9faa", "key": "CTYPE-109", "title": "Cancel obsolete rules-editor checks without publishing stale results", "type": "STORY", "priority": "MEDIUM", "difficulty": "ADVANCED", "estimateMinutes": 180, "phaseId": "stability", "dependsOn": [ "CTYPE-107", "CTYPE-108" ], "scenario": "Editor edits finish out of order and older type errors replace current diagnostics. Scope checking to document version.", "acceptanceCriteria": [ "Only current version publishes", "Cancellation releases resources", "Late completion cannot overwrite" ], "implementationNotes": [ "Include document identity as well as version." ], "verification": [ "Complete current check", "Resolve old check after replacement" ], "deliverables": [ "Versioned checking coordinator" ], "rollout": "Run serial checks if publication ownership fails.", "skills": [ "Concurrency", "Language tooling" ], "fieldMix": [ { "field": "Compiler and language tooling", "percentage": 80 }, { "field": "Performance engineering", "percentage": 20 } ], "patterns": [] }, { "id": "85101b60-aeb7-447d-a468-5b67acf76cd7", "key": "CTYPE-110", "title": "Bound rules-editor inference work with explicit incomplete status", "type": "CHORE", "priority": "MEDIUM", "difficulty": "EXPERT", "estimateMinutes": 210, "phaseId": "stability", "dependsOn": [ "CTYPE-105", "CTYPE-109" ], "scenario": "Adversarial nested constraints consume excessive work. Add operation and depth budgets with honest termination status.", "acceptanceCriteria": [ "Supported fixtures complete", "Budget exhaustion is explicit", "Incomplete checks cannot claim type safety" ], "implementationNotes": [ "Use deterministic counters rather than wall time alone." ], "verification": [ "Check normal corpus", "Exceed constraint budget" ], "deliverables": [ "Inference budget and stress cases" ], "rollout": "Lower limits and mark affected files incomplete until improved.", "skills": [ "Resource limits", "Static analysis" ], "fieldMix": [ { "field": "Compiler and language tooling", "percentage": 60 }, { "field": "Performance engineering", "percentage": 40 } ], "patterns": [] } ] } ] }