Extra components

Lint rule to warn when a composite field contains more components than its datatype profile defines.

What it does

Flags fields whose repetitions contain more components than the datatype's profile allows. For composite datatypes, the maximum is the highest sequence key in the datatype definition; for primitive datatypes the maximum is 1 (the value itself). The rule reads profile context attached by @glion/annotate-profile-context. Empty fields, fields on unknown segments, and fields whose datatype definition is missing are silently skipped.

Install

npm install @glion/lint-profile-extra-components

Use

import { hl7v2AnnotateProfileContext } from "@glion/annotate-profile-context";
import { hl7v2Parser } from "@glion/parser";
import hl7v2LintExtraComponents from "@glion/lint-profile-extra-components";
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(hl7v2LintExtraComponents)
  .process(message);

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

API

unified().use(hl7v2LintExtraComponents)

A unified lint rule plugin. Takes no options.

Reads file.data.profile. For each non-empty field it resolves the datatype definition. For primitives the allowed component count is 1; for composites it is the highest key in dtDef.componentsBySequence. Every component at a position greater than that max produces one message per offending repetition.

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

declare const hl7v2LintExtraComponents: Plugin<[], Root>;
export default hl7v2LintExtraComponents;

What it checks

This rule flags ^-delimited components past the profile's defined range for a datatype. PID-8 (Administrative Sex) is a primitive field in v2.5, so it allows exactly one component.

Valid

PID-8 has a single component (F), which matches the primitive limit:

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-8 has two components (F^EXTRA), which exceeds the v2.5 primitive limit of 1:

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

Reported message:

Component PID-8.2 is beyond the defined components for IS (max: 1 in v2.5)

The datatype code (for example IS, CX, XPN) comes from the field's profile. For composite datatypes the same rule applies — a CX field in v2.5 defines up to 10 components, so a value carrying an 11th is reported against that datatype.