Validation

Every call to parseScheduleDataSet runs the full spec validator against the parsed result. The validator implements the rules from IATA SSIM, Chapter 7, §§ 7.5.1–7.5.5 (March 2012 edition) — that is the authoritative reference this library is built against.

Newer editions

If you have access to a more recent edition of SSIM, please open an issue — newer editions may add DEI codes or revise byte assignments and we want to fold those in. The library is validated against the March 2011 and March 2012 editions today; the only material delta between them is the Secure Flight Indicator at byte 169 of the Carrier record (effective 1 Oct 2012).

What gets checked

The validator covers field-level Status (M Mandatory / C Conditional / O Optional), value formats, and cross-record consistency. Highlights:

• § 7.5.1 Header — canonical Title of Contents, recordSerialNumber === 1.
• § 7.5.2 Carrier — Time Mode (U/L), IATA airline code format, mandatory date parsing, validFrom ≤ validTo, Schedule Status (P/C), Secure Flight Indicator (S/X/blank, eff. 1 Oct 2012), Electronic Ticketing (EN/ET/blank).
• § 7.5.3 Flight Leg — IATA airline + 4-digit flight number, IVI / leg sequence 01–99, period validity, at least one Day of Operation, 3-letter station codes, all four times parse, both UTC offsets, PRBD or Aircraft Configuration mandatory.
• § 7.5.4 Segment Data — identification fields, single-alpha board/off-point indicators, 3-digit DEI, 3-letter board/off points.
• § 7.5.5 Trailer — Continuation/End Code (C/E), serialNumberCheckReference === recordSerialNumber − 1.
• Cross-record — every Type 3/4/5 record's airline designator must match the opening Type 2 Carrier Record.

See SDS → Error Handling for the complete rule catalogue.

Two modes

Lenient (default)

Issues are collected as ScheduleDataSetWarning entries on the returned object:

import { parseScheduleDataSet } from 'iata-ssim/sds'

const dataSet = parseScheduleDataSet(text)

for (const w of dataSet.warnings) {
  console.warn(`${w.rule} — line ${w.lineNumber}:${w.column}: ${w.message}`)
  // [§ 7.5.2 Time Mode] line 2:2: Time Mode must be "U" (UTC) or "L" (Local), got "A".
}

Each warning carries the byte-precise location: lineNumber, column, endColumn. IDE / terminal integrations turn file:line:col into clickable links.

Strict

The first issue throws ScheduleDataSetParseError:

import { parseScheduleDataSet, ScheduleDataSetParseError } from 'iata-ssim/sds'

try {
  parseScheduleDataSet(text, { strict: true })
}
catch (err) {
  if (err instanceof ScheduleDataSetParseError) {
    console.error(`${err.recordType}/${err.field} @ ${err.lineNumber}: ${err.message}`)
  }
}

Real-world tested

The library is validated against 14 real SSIM files from 10 different public sources, totalling ≈ 48 500 flight legs — including a 36 468-leg American Airlines 2015 production schedule. Across all clean files there are zero false positives; every issue surfaced on non-clean files is a real spec deviation (mostly cross-record airline mismatches and missing-mandatory-field violations).

See samples-validator/ in the repository for the bulk validation script. Run pnpm samples:validate for a compact summary or pnpm samples:validate:verbose for ESLint-style per-issue output with caret markers.

Try it yourself

The Playground runs the parser and validator entirely in your browser — drop a .ssim file or paste contents and inspect issues in the Warnings tab. Click any warning row to highlight the offending bytes in the source.