worldmonitor/todos/192-pending-p3-perf-micro-cleanups.md

status, priority, issue_id, tags, dependencies

status	priority	issue_id	tags	dependencies
pending	p3	192	code-review phase-0 regional-intelligence performance safety

Performance micro-cleanups (buildPreMeta x8, signal indexing, evidence chokepoint filter, prototype-pollution guards)

Problem Statement

Several minor perf and safety cleanups:

1. buildPreMeta(sources) is called 8x with identical results (only depends on sources, not regionId). Hoist out of computeSnapshot into main().
2. signals.filter(theater substring) rebuilds per region in balance-vector.mjs and evidence-collector.mjs. Precompute signalsByRegion Map once in main().
3. evidence-collector.mjs:62-77 iterates ALL chokepoints regardless of region. Filter by getRegionCorridors(regionId).map(c => c.chokepointId).
4. geography.js:countryCriticality() and regionForCountry() use bracket access on plain objects - prototype pollution risk if iso2 is __proto__. Use Object.hasOwn() guard.
5. JSON.stringify(snapshot) happens twice in persist-snapshot.mjs (for tsKey and idKey). Stringify once, reuse.
6. actor-scoring.mjs, balance-vector.mjs, scenario-builder.mjs JSON.stringify on caseFile not wrapped in try/catch. Circular references in upstream payload would crash the seed for all 8 regions.

Findings

• #1-3, #5 are pure perf: redundant work per region
• #4 is a safety issue (bracket access on user-supplied string keys)
• #6 is a reliability issue (one bad forecast crashes the whole seed)
• All items small, independent, safe

Proposed Solutions

Option 1: Do all 6 in one PR

Small mechanical cleanups; low risk.

Pros: Single follow-up Cons: Mix of concerns Effort: Small (each item) Risk: Low

Option 2: Split perf vs safety

(a) perf micros (#1, #2, #3, #5), (b) safety (#4, #6).

Pros: Each PR has a clean theme Cons: More overhead Effort: Small Risk: Low

Recommended Action

Technical Details

Affected files:

• scripts/seed-regional-snapshots.mjs - main(), computeSnapshot, buildPreMeta call site
• scripts/regional-snapshot/balance-vector.mjs - signals.filter, caseFile stringify
• scripts/regional-snapshot/evidence-collector.mjs:62-77 - chokepoint iteration
• scripts/regional-snapshot/actor-scoring.mjs - caseFile stringify
• scripts/regional-snapshot/scenario-builder.mjs - caseFile stringify
• scripts/regional-snapshot/persist-snapshot.mjs - double stringify
• shared/geography.js - countryCriticality, regionForCountry

For #4, pattern:

if (!Object.hasOwn(table, iso2)) return fallback;
return table[iso2];

For #6, wrap each JSON.stringify(f?.caseFile ?? ...) in try/catch and fall back to "{}" (ties in naturally with issue #190's precompute-once).

Acceptance Criteria

• buildPreMeta hoisted to main()
• signalsByRegion indexed once
• Chokepoint evidence filtered by region corridors
• Object.hasOwn guards on geography lookups
• JSON.stringify(snapshot) called once per region
• caseFile JSON.stringify wrapped in try/catch with fallback to {}

Work Log

Resources

• PR #2940
• PR #2942