Merge pull request #1017 from Financial-Times/named-middleware

Explicitly name all middleware functions to improve OpenTelemetry spans

Author: ivomurrell

main.js

@@ -88,7 +88,7 @@ const getAppContainer = (options) => {
 
 	// Debug related headers.
 	app.use(
-		/** @type {Callback} */ (req, res, next) => {
+		/** @type {Callback} */ function setDebugHeaders (req, res, next) {
 			res.set('FT-App-Name', meta.name);
 			res.set('FT-Backend-Timestamp', new Date().toISOString());
 			res.set('FT-System-Code', meta.systemCode);

src/middleware/backend-authentication.js

@@ -35,41 +35,40 @@ module.exports = (app) => {
 		return;
 	}
 
-	// @ts-ignore
-	app.use(
-		/** @type {Express.Handler} */ (req, res, next) => {
-			// allow static assets, healthchecks, etc., through
-			if (req.path.indexOf('/__') === 0) {
-				next();
-			} else if (
-				backendKeys.includes(
-					/** @type {string} */ (req.get('FT-Next-Backend-Key'))
-				)
-			) {
-				res.set('FT-Backend-Authentication', 'true');
-				next();
-			} else if (
-				backendKeys.includes(
-					/** @type {string} */ (req.get('FT-Next-Backend-Key-Old'))
-				)
-			) {
-				res.set('FT-Backend-Authentication', 'true');
-				next();
+	/** @type {Express.Handler} */
+	const backendAuthentication = (req, res, next) => {
+		// allow static assets, healthchecks, etc., through
+		if (req.path.indexOf('/__') === 0) {
+			next();
+		} else if (
+			backendKeys.includes(
+				/** @type {string} */ (req.get('FT-Next-Backend-Key'))
+			)
+		) {
+			res.set('FT-Backend-Authentication', 'true');
+			next();
+		} else if (
+			backendKeys.includes(
+				/** @type {string} */ (req.get('FT-Next-Backend-Key-Old'))
+			)
+		) {
+			res.set('FT-Backend-Authentication', 'true');
+			next();
+		} else {
+			res.set('FT-Backend-Authentication', 'false');
+			if (process.env.NODE_ENV === 'production') {
+				// Setting the WWW-Authenticate header tells ft.com-cdn
+				// to serve stale content instead of 401s if there's a key error.
+				res.set('WWW-Authenticate', 'FT-Backend-Key');
+				res.status(401).json({
+					status: 'Error',
+					reason: 'Invalid backend key',
+					source: 'n-express'
+				});
 			} else {
-				res.set('FT-Backend-Authentication', 'false');
-				if (process.env.NODE_ENV === 'production') {
-					// Setting the WWW-Authenticate header tells ft.com-cdn
-					// to serve stale content instead of 401s if there's a key error.
-					res.set('WWW-Authenticate', 'FT-Backend-Key');
-					res.status(401).json({
-						status: 'Error',
-						reason: 'Invalid backend key',
-						source: 'n-express'
-					});
-				} else {
-					next();
-				}
+				next();
 			}
 		}
-	);
+	};
+	app.use(backendAuthentication);
 };

src/middleware/consent.js

@@ -5,7 +5,7 @@
 /**
  * @type {Callback}
  */
-module.exports = (req, res, next) => {
+const consent = (req, res, next) => {
 	res.locals = res.locals || {};
 	res.locals.consent = res.locals.consent || {};
 
@@ -28,3 +28,5 @@ module.exports = (req, res, next) => {
 	}
 	next();
 };
+
+module.exports = consent;

src/middleware/security.js

@@ -5,9 +5,10 @@
 /**
  * @type {Callback}
  */
-module.exports = (_req, res, next) => {
+const security = (_req, res, next) => {
 	res.set('X-Content-Type-Options', 'nosniff');
 	res.set('X-Download-Options', 'noopen');
 	res.set('X-XSS-Protection', '1; mode=block');
 	next();
 };
+module.exports = security;

src/middleware/vary.js

@@ -18,7 +18,7 @@ const extendVary = (val, set) => {
 /**
  * @type {Callback}
  */
-module.exports = (_req, res, next) => {
+const vary = (_req, res, next) => {
 	const resSet = res.set;
 
 	/** @type {Set<string>} */
@@ -74,3 +74,5 @@ module.exports = (_req, res, next) => {
 
 	next();
 };
+
+module.exports = vary;