Required fields

Lint rule to validate required fields per HL7v2 profile.

What it does

Flags segments whose required fields (as declared by the HL7v2 profile for the message's version) are missing or empty. The rule reads profile context attached to the file by @glion/annotate-profile-context and reports one message per missing required field. Segments without a known profile (for example Z-segments like ZPD) are silently skipped.

Install

npm install @glion/lint-profile-required-fields

Use

import { hl7v2AnnotateProfileContext } from "@glion/annotate-profile-context";
import { hl7v2Parser } from "@glion/parser";
import hl7v2LintRequiredFields from "@glion/lint-profile-required-fields";
import { unified } from "unified";
import { reporter } from "vfile-reporter";

const message = [
  "MSH|^~\\&|SENDER|FAC|RECV|RFAC|20250601120000||ADT^A01^ADT_A01|MSG00001|P|2.5",
  "PID|1||PATID1234^^^HOSP^MR||DOE^JANE||19800101|F",
].join("\r");

const file = await unified()
  .use(hl7v2Parser)
  .use(hl7v2AnnotateProfileContext)
  .use(hl7v2LintRequiredFields)
  .process(message);

console.error(reporter([file]));

API

unified().use(hl7v2LintRequiredFields)

A unified lint rule plugin. Takes no options.

The plugin reads file.data.profile (populated by @glion/annotate-profile-context). If no profile context is present the rule exits silently. For each segment, it iterates fieldDef.requiredSequences and checks that the corresponding field at that 1-based position is present and non-empty.

import type { Plugin } from "unified";
import type { Root } from "@glion/ast";

declare const hl7v2LintRequiredFields: Plugin<[], Root>;
export default hl7v2LintRequiredFields;

What it checks

This rule flags fields declared required: true in the HL7v2 profile for the message's version when those fields are missing or empty on the corresponding segment.

Valid

PID-3 (Patient Identifier List) and PID-5 (Patient Name) are required in v2.5 and both are populated:

MSH|^~\&|SENDER|FAC|RECV|RFAC|20250601120000||ADT^A01^ADT_A01|MSG00001|P|2.5
PID|1||PATID1234^^^HOSP^MR||DOE^JANE||19800101|F

Invalid

PID-3 is empty, which violates the v2.5 profile for the PID segment:

MSH|^~\&|SENDER|FAC|RECV|RFAC|20250601120000||ADT^A01^ADT_A01|MSG00001|P|2.5
PID|1||||DOE^JANE||19800101|F

Reported message:

Required field PID-3 (Patient Identifier List) is missing or empty

When the profile attaches a field name, it appears in parentheses after the position. Segments shorter than the highest required sequence produce one message per missing required field.