Refactor express handlers, update Changelog

Author: Michal Vlasák

CHANGELOG.md

@@ -3,9 +3,13 @@
 ### Fixed
 - lint issue due to changes in tslint 5.12.0
 - stream write function type
+- pretty streams created only when needed
 
 ### Added
 - coveralls integration
+  
+## Changed
+- refactoring of express handlers
 
 ## [1.0.3] - 2018-11-08
 

src/express.ts

@@ -5,52 +5,59 @@ import { AckeeLogger } from '.';
 
 const errorSymbol = Symbol.for('error');
 
+type AckeeRequest = Request & { _startAt?: [number, number]; ackId?: string };
+type AckeeResponse = Response & { _startAt?: [number, number]; time?: string; out?: object; [errorSymbol]?: any };
+
 export type AckeeLoggerExpressMiddleware = (
     this: AckeeLogger,
-    req: Request & { _startAt?: [number, number]; ackId?: string },
-    response: Response & { _startAt?: [number, number]; time?: string; out?: object; [errorSymbol]?: any },
+    req: AckeeRequest,
+    response: AckeeResponse,
     next: any
 ) => void;
 
+const expressOnHeaders = (req: AckeeRequest, res: AckeeResponse) => () => {
+    res._startAt = process.hrtime();
+    const diffFromSeconds = (res._startAt[0] - req._startAt![0]) * 1e3;
+    const diffFromNanoseconds = (res._startAt[1] - req._startAt![1]) * 1e-6;
+    const ms = diffFromSeconds + diffFromNanoseconds;
+    res.time = ms.toFixed(3);
+};
+
+const expressOnFinished = (logger: AckeeLogger, req: AckeeRequest) => (_err: Error | null, res: AckeeResponse) => {
+    const error = res[errorSymbol];
+    const reqOut = `${res.statusCode} ${req.method} ${req.originalUrl} ${res.time} ms ${req.headers['user-agent']}`;
+    if (logger.options.ignoredHttpMethods && logger.options.ignoredHttpMethods.includes(req.method)) {
+        return;
+    }
+    const standardOutput = {
+        data: {
+            req,
+            res,
+            ackId: req.ackId,
+        },
+        message: `${reqOut} - Standard output`,
+    };
+
+    if (error) {
+        logger.error({ error, req, res, ackId: req.ackId }, `${reqOut} - Error handler at the end of app`);
+    } else if (res.out) {
+        logger.debug(standardOutput.data, standardOutput.message);
+    } else {
+        logger.info(standardOutput.data, standardOutput.message);
+    }
+};
+
 const expressMiddleware: RequestHandler = function(
     this: AckeeLogger,
-    req: Request & { _startAt?: [number, number]; ackId?: string },
-    response: Response & { _startAt?: [number, number]; time?: string; out?: object; [errorSymbol]?: any },
+    req: AckeeRequest,
+    response: AckeeResponse,
     next: any
 ) {
     const reqIn = `--- ${req.method} ${req.originalUrl} ${req.headers['user-agent']}`;
     this.debug({ req, ackId: req.ackId }, `${reqIn} - Request accepted`);
     req._startAt = process.hrtime();
-    onHeaders(response, () => {
-        response._startAt = process.hrtime();
-        const diffFromSeconds = (response._startAt[0] - req._startAt![0]) * 1e3;
-        const diffFromNanoseconds = (response._startAt[1] - req._startAt![1]) * 1e-6;
-        const ms = diffFromSeconds + diffFromNanoseconds;
-        response.time = ms.toFixed(3);
-    });
-    onFinished(response, (_err, res) => {
-        const error = res[errorSymbol];
-        const reqOut = `${res.statusCode} ${req.method} ${req.originalUrl} ${res.time} ms ${req.headers['user-agent']}`;
-        if (this.options.ignoredHttpMethods && this.options.ignoredHttpMethods.includes(req.method)) {
-            return;
-        }
-        const standardOutput = {
-            data: {
-                req,
-                res,
-                ackId: req.ackId,
-            },
-            message: `${reqOut} - Standard output`,
-        };
-
-        if (error) {
-            this.error({ error, req, res, ackId: req.ackId }, `${reqOut} - Error handler at the end of app`);
-        } else if (res.out) {
-            this.debug(standardOutput.data, standardOutput.message);
-        } else {
-            this.info(standardOutput.data, standardOutput.message);
-        }
-    });
+    onHeaders(response, expressOnHeaders(req, response));
+    onFinished(response, expressOnFinished(this, req));
     next();
 };