how to log the file requested via express.static

Question

here is my code

var express=require(\"express\");
var app=express();
var port=8181;
app.use(express.static(__dirname));
app.listen(port);

it i

Answer 1

You want to log what serve-static (express.static) gives in response. There're several ways to do this.

^{Method Ⅰ} A middleware for manual checks.

You may put (app.use) a middleware that logs a request if it's for express.static, before express.static. Rodrigo Medeiros' answer does this. But this way, you have to rewrite the code for checks when the options for the serve-static middleware changes, which might be a maintaining issue.

^{Method Ⅱ} Hooking into express.static; leaking info out of it.

Well, express.static knows what files it gives best. It just, unfortunately, does not let us know and log it. But there's a hack for this: the setHeaders option, which is a callback function supposedly used to set custom response headers. It's called when express.static makes a response and gets enough information to log what you want to.

const express = require("express");
const path = require("path");
const app = express();
const asset_dir_path = "assets/";

app.use(express.static(asset_dir_path, {
    index: false,
    setHeaders: (response, file_path, file_stats) => {
        // This function is called when “serve-static” makes a response.
        // Note that `file_path` is an absolute path.

        // Logging work
        const relative_path = path.join(asset_dir_path, path.relative(asset_dir_path, file_path));
        console.info(`@${Date.now()}`, "GAVE\t\t", relative_path);
    }
}));