Integer.d.ts

[janwo]

I just upgraded to the latest npm package and changed the importings accordingly. However...

import Integer from "neo4j-driver/types/v1/integer";
...
if (obj instanceof Integer) return Integer.toNumber(obj);

...results in a error...

Cannot find module 'neo4j-driver/types/v1/integer

Why?

[lutovich]

Hi @janwo,

I do not think you need to change imports. Those TypeScript declaration files are just type declarations, right? They do not contain any actual executable JavaScript code and modules. TypeScript knows how to extract types from NPM package and should use those defined in types folder. Your IDE should also just pick existing TypeScript declarations and make better code completion suggestions.

Hope this helps.

[janwo]

@lutovich When I make no changes to my imports, I get this error message:

Could not find a declaration file for module 'neo4j-driver/lib/v1/record'. 
'/root/app/node_modules/neo4j-driver/lib/v1/record.js' implicitly has an 'any' type.
`npm install @types/neo4j-driver/lib/v1/record` if it exists or add a new declaration (.d.ts) file containing `declare module 'neo4j-driver/lib/v1/record'`

Typescript 2.4

[lutovich]

@janwo this definitely does not sound right. Could you please share an example project to reproduce this problem?

[janwo]

@lutovich I´ve extracted an example: https://github.com/janwo/neo4j-test

npm install && npm start

[lutovich]

@janwo I'm able to make your code compile by changing imports to:

import neo4j from "neo4j-driver";
import {Driver} from "neo4j-driver/types/v1/driver";
import Integer from "neo4j-driver/types/v1/integer";
import Record from "neo4j-driver/types/v1/record";
import Transaction from "neo4j-driver/types/v1/transaction";
import Session from "neo4j-driver/types/v1/session";
import {AuthToken} from "neo4j-driver/types/v1";

and DatabaseManager#get() function to:

public static get(): Driver {
    const authToken: AuthToken = neo4j.auth.basic("user", "pwd");
    const driver: Driver = neo4j.driver(`bolt://`, authToken);
    if(!DatabaseManager.neo4jClient) DatabaseManager.neo4jClient = driver;
    return this.neo4jClient;
}

I think import {auth, driver} from "neo4j-driver/types/v1"; does not work because this file only contains TS declarations for auth and driver functions. Rest of imports import only type declarations. So actual executable JS code still needs to be imported via import neo4j from "neo4j-driver";.

What do you think?

[janwo]

I tried this as well. I used that approach when I created this issue. Nevertheless I now pushed the Integer check. And then it does not compile anymore. Actually you are right. There should be no need to change from **/lib/** to **/types/**.

[lutovich]

I'm not entirely sure why this does not work. It has probably something to do with instanceof operator which requires right operand to be a function.

However driver's JS code does not export Integer as a type constructor. It only exports functions to work with integers like int and isInt. Could you please use the following code without instanceof:

if(neo4j.isInt(obj)) {
    const i = obj as Integer;
    console.log('hooray');
}

[janwo]

But with Record we have the Scenario and it did work. Also the types of @SnappyCroissant made this work. Unfortunately the new types do not allow this. However I am going to use your suggestion now. Thank you for your time :)

[lutovich]

Oh, so it used to work with TypeScript declarations from this PR #183? I'd expect it it work with updated types than, otherwise it's a problem. Do you have an example where Record does not work?

[janwo]

Yes, the PR is correct. No, sorry. What I meant was the structure of the declaration file of Integer and Record. In both files the class is the default export, but whyever it does only fail in the Integer class.

[pocesar]

have you tried enabling allowSyntheticDefaultImports in tsconfig.json? this setting is to make interoperable code with non-es modules (lilke this module that is commonjs)

[janwo]

It says: "Allow default imports from modules with no default export. This does not affect code emit, just typechecking." But all declaration files do have a default export. Also interesting in this case: MikeMcl/bignumber.js#97.

Anyway, I got it working with a minor change in integer.d.ts, see my PR.