@actuarial-ts/data

Data ingestion and ASOP No. 23 data-quality review for the actuarial-ts SDK. Pure functions, zero runtime dependencies (besides @actuarial-ts/core), fully typed.

• parseCsv(text) — minimal RFC 4180-subset CSV parser (quoted fields, escaped quotes, embedded commas/newlines, BOM, CRLF/LF).
• parseLossRunCsv(text) — loss-run import to ClaimSnapshot[] with per-row validation errors (1-based row numbers including the header).
• triangleFromLongFormat(rows, { kind }) — pivots long-format (origin, age, value) rows into a Triangle.
• reviewClaimData(claims, { asOfDate? }) / reviewTriangles(paid, incurred) — the ASOP No. 23-oriented review; every check performed is listed in the report, pass or fail, so the actuary's disclosure can state what WAS reviewed, not just what was found.

Checks

reviewClaimData

| id | status when found | what it finds | |----|-------------------|---------------| | negative-paid | fail | cumulative paid < 0 | | negative-case | warning | case reserve < 0 (legitimate but rare) | | paid-decreasing | fail | cumulative paid decreasing across a claim's snapshots ordered by evaluation date | | date-order | fail | report before accident, or evaluation before report | | duplicate-snapshot | fail | same claimId + evaluationDate twice | | future-dated | fail | any claim date after asOfDate (not evaluated when asOfDate is omitted) | | closed-with-case | warning | closed claim still carrying case reserve |

reviewTriangles

| id | status when found | what it finds | |----|-------------------|---------------| | shape-mismatch | fail | origins/ages differ between paid and incurred (blocks cell-level checks, which stay listed as "not evaluated") | | paid-exceeds-incurred | fail | paid > incurred in a cell (1e-9 relative tolerance) | | negative-incremental-paid | warning | cumulative paid decreasing along a row (salvage/subrogation makes this legal but reportable) | | negative-incremental-incurred | warning | cumulative incurred decreasing along a row | | interior-missing | warning | a null cell with observed cells both before and after it in the same row |

Quickstart

import { buildTriangles } from "@actuarial-ts/core";
import { parseLossRunCsv, reviewClaimData, reviewTriangles } from "@actuarial-ts/data";

const { claims, errors } = parseLossRunCsv(csvText);
if (errors.length > 0) console.warn(errors); // caller decides: abort or proceed

const claimReview = reviewClaimData(claims, { asOfDate: "2023-12-31" });

const { paid, incurred } = buildTriangles(claims, {
  cadence: "annual",
  asOfDate: "2023-12-31",
});
const triangleReview = reviewTriangles(paid, incurred);

These utilities are designed to support the actuary's compliance with ASOP No. 23; responsibility for compliance remains with the credentialed actuary.

License

Apache-2.0. See LICENSE and NOTICE.