Required components

Lint rule that reports a required component that is missing or empty.

What it does

Flags a component that the HL7v2 standard for the message's version marks R (required) when it is missing or empty in a field that has a value. Before v2.5 the standard marks no component as required, so the rule reports nothing for older versions. Empty fields are left to @glion/lint-profile-required-fields. It needs the plugins @glion/annotate-profile-context and @glion/annotate-profile-fields to run before it; @glion/preset-lint-profile-recommended includes them.

Install

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

Use

import { hl7v2AnnotateProfileContext } from "@glion/annotate-profile-context";
import { hl7v2AnnotateProfileFields } from "@glion/annotate-profile-fields";
import hl7v2LintRequiredComponents from "@glion/lint-profile-required-components";
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^|MSG00001|P|2.5",
  "PID|1||PATID1234^^^HOSP^MR||DOE^JANE||19800101|F",
].join("\r");

const file = new VFile();
await unified()
  .use(hl7v2AnnotateProfileContext)
  .use(hl7v2AnnotateProfileFields)
  .use(hl7v2LintRequiredComponents)
  .run(parseHL7v2(message), file);

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

API

`unified().use(hl7v2LintRequiredComponents)`

A unified lint rule plugin. Takes no options. Reports one message for each required component that is missing or empty, in each repetition.

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

declare const hl7v2LintRequiredComponents: Plugin<[], Root>;
export default hl7v2LintRequiredComponents;

What it checks

In a field that has a value, every component marked R in the message's version is present and not empty. For example, in v2.5 MSH-9 (Message Type) requires the message code (MSH-9.1), the trigger event (MSH-9.2) and the message structure (MSH-9.3).

Valid

MSH-9 has all three components:

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

Invalid

MSH-9.2 is empty and MSH-9.3 is missing:

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

Reported messages:

The component is empty; it is required.
Component `MSH-9.3` (Message Structure) is not present; it is required.

Required components

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