@glion/lint-profile-backward-compatible

Lint rule that reports a value in an element HL7v2 keeps only for backward compatibility.

What it does

Flags a field, component, or subcomponent that has a value although the HL7v2 standard for the message's version marks it B (backward compatible). HL7v2 keeps such an element so older systems can still send it, and another element now carries its data. A value is still allowed, so @glion/preset-lint-profile-recommended reports it as a warning. It needs the plugins @glion/annotate-profile-context, @glion/annotate-profile-fields and @glion/annotate-profile-datatypes to run before it; @glion/preset-lint-profile-recommended includes them.

Install

npm install @glion/lint-profile-backward-compatible

Use

import { hl7v2AnnotateProfileContext } from "@glion/annotate-profile-context";
import { hl7v2AnnotateProfileDatatypes } from "@glion/annotate-profile-datatypes";
import { hl7v2AnnotateProfileFields } from "@glion/annotate-profile-fields";
import hl7v2LintBackwardCompatible from "@glion/lint-profile-backward-compatible";
import { parseHL7v2 } from "@glion/parser";
import { unified } from "unified";
import { VFile } from "vfile";
import { reporter } from "vfile-reporter";

const message = [
  "MSH|^~\\&|SENDER|FAC|RECV|RFAC|20250601120000||ADT^A01^ADT_A01|MSG00001|P|2.5.1",
  "DG1|1|I9|250.00|DIABETES",
].join("\r");

const file = new VFile();
await unified()
  .use(hl7v2AnnotateProfileContext)
  .use(hl7v2AnnotateProfileFields)
  .use(hl7v2AnnotateProfileDatatypes)
  .use(hl7v2LintBackwardCompatible)
  .run(parseHL7v2(message), file);

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

API

unified().use(hl7v2LintBackwardCompatible)

A unified lint rule plugin. Takes no options. Reports one message for each backward-compatible element that has a value.

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

declare const hl7v2LintBackwardCompatible: Plugin<[], Root>;
export default hl7v2LintBackwardCompatible;

What it checks

An element whose optionality is B in the message's version should be empty. The explicit null "" is accepted. For example, in v2.5.1 the field DG1-4 (Diagnosis Description) is backward compatible, and DG1-3 (Diagnosis Code) carries the diagnosis.

Valid

DG1-4 is empty in a v2.5.1 message:

MSH|^~\&|SENDER|FAC|RECV|RFAC|20250601120000||ADT^A01^ADT_A01|MSG00001|P|2.5.1
DG1|1|I9|250.00

Invalid

DG1-4 has a value in a v2.5.1 message:

MSH|^~\&|SENDER|FAC|RECV|RFAC|20250601120000||ADT^A01^ADT_A01|MSG00001|P|2.5.1
DG1|1|I9|250.00|DIABETES

Reported message:

The data element has a value; v2.5.1 keeps it only for backward compatibility.

A field is reported once, whichever of its repetitions has a value. A component is reported in each repetition that gives it a value.

Part of Glion

@glion/lint-profile-backward-compatible is part of Glion, the application framework for HL7v2. See the Glion README for the full package catalog and architecture.