feat(routes): add hl7v2-to-json route

Fdawgs · Fdawgs · commit 2a9e33308488 · 2023-05-30T21:11:59.000+01:00
diff --git a/README.md b/README.md
@@ -18,6 +18,7 @@ Docsmith is a RESTful API, built using Node.js and the [Fastify](https://fastify
 | DOC   | TXT    | DOT file variant supported                   |
 | DOCX  | HTML   | DOCM, DOTM, and DOTX file variants supported |
 | DOCX  | TXT    | DOCM, DOTM, and DOTX file variants supported |
+| HL7v2 | JSON   |                                              |
 | HTML  | TXT    |                                              |
 | PDF   | HTML   |                                              |
 | PDF   | TXT    | Scanned documents supported using OCR        |
diff --git a/package-lock.json b/package-lock.json
diff --git a/package.json b/package.json
@@ -100,6 +100,7 @@
 		"@fastify/static": "^6.10.2",
 		"@fastify/swagger": "^8.5.1",
 		"@fastify/under-pressure": "^8.2.0",
+		"@redoxengine/redox-hl7-v2": "^1.0.1",
 		"cfb": "^1.2.2",
 		"clean-css": "^5.3.2",
 		"cssesc": "^3.0.0",
diff --git a/src/config/index.js b/src/config/index.js
@@ -293,6 +293,11 @@ async function getConfig() {
 						description:
 							"Endpoints used for the conversion of DOTX documents",
 					},
+					{
+						name: "HL7v2",
+						description:
+							"Endpoints used for the conversion of HL7 v2.x messages",
+					},
 					{
 						name: "HTML",
 						description:
diff --git a/src/plugins/hl7v2-to-json/index.js b/src/plugins/hl7v2-to-json/index.js
@@ -0,0 +1,44 @@
+const fp = require("fastify-plugin");
+const hl7v2 = require("@redoxengine/redox-hl7-v2");
+
+/**
+ * @author Frazer Smith
+ * @description Pre-handler plugin that uses redox-hl7-v2 to convert string containing
+ * HL7 v2.x in `req.body` to JSON.
+ * `req` object is decorated with `conversionResults.body` holding the converted document.
+ * @param {object} server - Fastify instance.
+ */
+async function plugin(server) {
+	const parser = new hl7v2.Parser();
+
+	server.addHook("onRequest", async (req) => {
+		req.conversionResults = { body: undefined };
+	});
+
+	server.addHook("preHandler", async (req) => {
+		/**
+		 * `htmlToText` function still attempts to parse empty bodies/input or invalid HTML
+		 * and produces results, so catch them here
+		 */
+		// if (req.body === undefined || Object.keys(req.body).length === 0) {
+		// 	throw server.httpErrors.badRequest();
+		// }
+
+		try {
+			const results = parser.parse(req.body);
+			req.conversionResults.body = results;
+		} catch {
+			/**
+			 * redox-hl7-v2 will throw if the HL7 v2 message provided
+			 * by client is malformed or invalid, thus client error code
+			 */
+			throw server.httpErrors.badRequest();
+		}
+	});
+}
+
+module.exports = fp(plugin, {
+	fastify: "4.x",
+	name: "hl7v2ToJson",
+	dependencies: ["@fastify/sensible"],
+});
diff --git a/src/routes/hl7v2/json/index.js b/src/routes/hl7v2/json/index.js
@@ -0,0 +1,69 @@
+// Import plugins
+const cors = require("@fastify/cors");
+const hl7v2ToJson = require("../../../plugins/hl7v2-to-json");
+
+const { hl7v2ToJsonPostSchema } = require("./schema");
+
+const accepts = hl7v2ToJsonPostSchema.produces;
+
+/**
+ * @author Frazer Smith
+ * @description Sets routing options for server.
+ * @param {object} server - Fastify instance.
+ * @param {object} options - Route config values.
+ * @param {*=} options.bearerTokenAuthKeys - Apply `bearerToken` security scheme to route if defined.
+ * @param {object} options.cors - CORS settings.
+ */
+async function route(server, options) {
+	if (options.bearerTokenAuthKeys) {
+		hl7v2ToJsonPostSchema.security = [{ bearerToken: [] }];
+		hl7v2ToJsonPostSchema.response[401] = {
+			$ref: "responses#/properties/unauthorized",
+			description: "Unauthorized",
+		};
+	}
+
+	server.addContentTypeParser(
+		hl7v2ToJsonPostSchema.consumes,
+		{ parseAs: "string" },
+		async (_req, payload) => {
+			/**
+			 * The Content-Type header can be spoofed so is not trusted implicitly,
+			 * this checks the payload is an HL7 v2.x message
+			 */
+			if (!payload.startsWith("MSH")) {
+				throw server.httpErrors.unsupportedMediaType();
+			}
+
+			return payload;
+		}
+	);
+
+	// Register plugins
+	await server
+		// Enable CORS if options passed
+		.register(cors, {
+			...options.cors,
+			methods: ["POST"],
+		})
+		.register(hl7v2ToJson);
+
+	server.route({
+		method: "POST",
+		url: "/",
+		schema: hl7v2ToJsonPostSchema,
+		onRequest: async (req) => {
+			if (
+				// Catch unsupported Accept header media types
+				!req.accepts().type(accepts)
+			) {
+				throw server.httpErrors.notAcceptable();
+			}
+		},
+		handler: (req, res) => {
+			res.send(req.conversionResults.body);
+		},
+	});
+}
+
+module.exports = route;
diff --git a/src/routes/hl7v2/json/schema.js b/src/routes/hl7v2/json/schema.js
@@ -0,0 +1,40 @@
+const S = require("fluent-json-schema");
+
+const tags = ["HL7 v2.x"];
+
+/**
+ * Fastify uses AJV for JSON Schema Validation,
+ * see https://fastify.io/docs/latest/Reference/Validation-and-Serialization/
+ *
+ * Input validation protects against XSS, HPP, prototype pollution,
+ * and most other injection attacks.
+ */
+const hl7v2ToJsonPostSchema = {
+	tags,
+	summary: "Convert HL7 v2.x message to JSON",
+	description:
+		"Returns the result of converting an HL7 v2.x message to JSON format.",
+	operationId: "postHl7v2ToJson",
+	consumes: ["text/hl7v2"],
+	produces: ["application/json"],
+	response: {
+		200: S.object().additionalProperties(true),
+		400: S.ref("responses#/properties/badRequest").description(
+			"Bad Request"
+		),
+		406: S.ref("responses#/properties/notAcceptable").description(
+			"Not Acceptable"
+		),
+		415: S.ref("responses#/properties/unsupportedMediaType").description(
+			"Unsupported Media Type"
+		),
+		429: S.ref("responses#/properties/tooManyRequests").description(
+			"Too Many Requests"
+		),
+		503: S.ref("responses#/properties/serviceUnavailable").description(
+			"Service Unavailable"
+		),
+	},
+};
+
+module.exports = { hl7v2ToJsonPostSchema };
