What did you learn this week?

For example, I've learnt that a green test written in the past might be a false positive test today.

Comments

[RussCoder]

I found that json rpc 2 is a much better protocol for inner API for admin dashboards. It's much simpler than REST, it's very clear.

I don't have to think how to call an endpoint according to the "REST rules", I don't have to bother about http cache, since all requests are POST, and using a proxy object on the client I can easily implement an interface looking as if I call a server-side method directly, e.g.

On the server:

const apiMethods = require('./innerApi');

app.post('/api/jsonrpc2', async (req, res) => {
    const data = req.body;
    try {
        if (!apiMethods[data.method]) {
            return res.send({
                id: data.id,
                error: { message: `No method "${data.method}"` },
            });
        }

        const result = await apiMethods[data.method](data.params);
        return res.send({
            id: data.id,
            result: result,
        });
    } catch (e) {
        res.send({
            id: data.id,
            error: { message: "Unexpected error. Message: " + e.message },
        })
    }
});

On the client:

let id = 1;

export const rpc = new Proxy({}, {
    get(target, prop) {
        return async (params) => {
            const data = await fetch('/api/jsonrpc2', {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({
                    jsonrpc: '2.0',
                    method: prop,
                    params: params,
                    id: id++,
                })
            }).then(r => r.json());

            if (data.error) {
                throw new Error(data.error.message);
            }
            return data.result;
        };
    },
});

And then I can just add a method on the server and call it on the client:

const result = await rpc.anyServerMethodHere(params)

which is very handy.

[NHKK]

It’s extremely painful to refactor code with no tests, no docs, and no history of its requirements