ExpressJS in a TypeScript class - express

Question

All ExpressJS and TypeScript examples I could find use
import * as express from "express";
let app = express();
app.use("/", express.static("/"));
However, I want to use the class approach:
import * as express from "express";
export class ServerApp {
private app: express.Express = express();
public configure {
this.app.use('/', express.static("/");
}
}
Trying to access the use method on the private variable gives an argument type warning.
I want to use strong typing so private app: any will not work. How can I solve this problem, or is there a better approach?

Answer 1

According to the latest express typings, the type for app is called Application, not Express. The following file test.ts compiles just fine
import * as express from "express";
export class ServerApp {
private app: express.Application = express();
public configure() {
this.app.use('/', express.static("/"));
}
}
if you put it in an empty directory and do
npm install typescript
npm install typings
./node_modules/.bin/typings install -G dt~node
./node_modules/.bin/typings install express
./node_modules/.bin/tsc test.ts typings/index.d.ts
it will work.
However, there is more than one way to install typings for express. If you don't need compatiblity with typescript < 2.0 (2.0 was released a few days ago), you can just
npm install typescript
npm install #types/express
./node_modules/.bin/tsc test.ts
and again it will work. If you look at installed types-metadata.json for express-serve-static-core, you notice that it uses types-2.0 branch of DefinitelyTyped:
"sourceRepoURL": "https://www.github.com/DefinitelyTyped/DefinitelyTyped",
"sourceBranch": "types-2.0",
The third way to install is
../node_modules/.bin/typings install -G dt~express
this will take it from the main branch of DefinitelyTyped, which, as #Aphelion discovered, contains problematic commit that removes a number of use overloads, causing the error in question.