By default, when requesting just "/", express.static() will serve up the index.html file (you can check this out in the documentation reference). Therefore, the index.html file is being served by the express.static() middleware, not by the app.get('/', ...) route.
Both of your app.get() routes are likely experiencing the same issue. The first one is not executed because the request is already being handled by the express.static() configuration, which is returning the index.html file.
The /report route is not processed by express.static() since the request for report is different from report.html. As a result, the middleware does not handle the request, causing your improperly configured app.get('/report', ...) to be called and resulting in an error.
The following code should resolve these issues:
var express = require("express");
var app = express();
app.use(express.static(__dirname + '/public'));
app.get('/report', function(req, res){
res.sendFile(__dirname + "/public/report.html");
});
app.listen(8080);
Alternatively, you can utilize the path module and concatenate the pieces with path.join():
var path = require("path");
You can then serve the file using this method:
res.sendFile(path.join(__dirname, 'public', 'report.html'));
In my personal nodejs application example, either of the above options for res.sendFile() work effectively.