I'm importing my reducers as follows import reducers from './reducers/index'; and using it inside the store const store = createStore(reducers);
index.js
Inside my index file I have import {combineReducers} from 'redux'; and I'm exporting as follows:
export default combineReducers({
obj: objsReducers,
objKop: objKopsReducers
})
Also I'm importing my required files from folders.
But still in my console logs, I'm outputting arrays, instead of objects. I want it to output as an object because isn't that what combineReducer is meant to do in Redux?
Like so, {objs: {…}, objkop: {…}}
Maybe a better question is: Does it matter if it outputs as an array?
Actually, as an official documentation says it should return:
Returns
(Function): A reducer that invokes every reducer inside the reducers object, and constructs a state object with the same shape.
You are doing it in a correct way, so I would suggest you continue with it and add a test action to test it properly.
Related
I have a controller that has a method that uses GET to return an object (json format). I want to call it from another controller.
In order to make it easier to understand, let's call the controllers controllerSrc (source) and controllerTgt (target).
First, I import the controller and instantiate the variable of the method.
const controllerSrc = require('controllerSrc')
const controllerSrcGET= controllerSrc.get
In theory, the controllerSrcGET returns a json object, so when I try to do:
console.log(controlerSrcGET._id)
I should have there the id of the object and work arount it. However, I get undefined.
Extra info
I am working with Morgan, and I've noticed that the GET request that should be printed is not. So I'm guessing that it is not enough to instantiate the controllerSrcGET(?)
I want to organize my firebase cloud functions in specific files,
and currently, I have these 3:
index.ts
crypto.ts
webscrape.ts
Inside of these files, I have functions that use specific dependencies that are needed nowhere else.
For example, in crypto.ts I need the crypto-js package to encrypt some user data and store it into the database.
So I am importing it like so:
import * as CryptoJS from "crypto-js";
as advised in https://firebase.google.com/docs/functions/handle-dependencies#typescript
On the other hand, when I try to import puppeteer into webscrape.ts like this:
import * as puppeteer from"puppeteer-extra";
then calling puppeteer.launch(); gives me an error :
Property 'launch' does not exist on type 'typeof import("c:/Users/username/Desktop/project/firebasee/functions/node_modules/puppeteer-extra/dist/index")'
and it only works when I do const puppeteer = require("puppeteer-extra");
What's the difference here?
My goal is to keep the dependencies of each functions and file/module as small as possible because I assume that this will also keep the size of each function container small (Is that even true?)
I didn't want to import everything to index.ts even when I trigger a function, that doesn't use this dependency at all.
So what is the correct way of handling these dependencies?
Thanks!
The following import will get the default export from that package.
import puppeteer from "puppeteer-extra"
I looked for the default export in the Github repository and found that.
const defaultExport: PuppeteerExtra = (() => {
return new PuppeteerExtra(...requireVanillaPuppeteer())
})()
export default defaultExport
They have mentioned both ES6 import and require methods here.
// javascript import
const puppeteer = require('puppeteer-extra')
// typescript/es6 module import
import puppeteer from 'puppeteer-extra'
You can read more about import on MDN.
I'm trying to access the decode() method in the jsQR module.
I found an example that called decode() directly but that was from an HTML file, not nodejs.
In visual code I see this...
I know that the default export is defined in index.d.ts but is there anyway of importing the other classes/functions on the rest of the dist folder?
I've tried to import using require("jsqr/decoder") and require("jsqr/decoder/decode") to no avail.
EDIT
To be clear, I don't want jsQR, the default export. That deals with images. I'm trying to explicitly call the decode() method in the pic which accepts a BitMatrix
There are no limitations in what you can require from node_modules. So, with your case it should look like:
TypeScript\ESM Modules:
import { decode } from 'jsqr/dist/decoder/decoder';
CommonJS:
const { decode } = require('jsqr/dist/decoder/decoder');
UPD: If you take a look into dist folder for jsqr package, you can find that there are only d.ts files. Which means that you can not import it from there.
But, you can find an actual export of the module here:
Which means that you should able to import it from jsqr:
const { decode } = require('jsqr');
I am having strange issues with Typescript when I import things from a file which exports them. Sometimes I will export a function, then import it to another file, then I use the function and it is not a function anymore. When I define the function in the same file, all of a sudden the function is a function?!?!?
Why would a function stop being a function when it is exported? I have had similar problems with classes too.
The hard part of this issue is I can't recreate a simple example because it only happens when I am using some kind of higher level package.
For example, I had a similar issue with sequelize-typescript here: my github issue with typescript-sequelize
Below is some codes showing off the basic issue I'm having with one of the decorators from InversifyJS.
container.ts
import {fluentProvide} from "inversify-binding-decorators";
export const provideSingleton = (identifier: any) => {
return fluentProvide(identifier)
.inSingletonScope()
.done(true);
};
test.service.ts
import {provideSingleton} from './container'
#provideSingleton(TYPES.TEST)
export default class TestService {}
The strangest thing is when I put the provideSingleton in the same file as the TestService, everything works!?!?!
Basically to recreate the issue, simply follow the example from here: inversify-binding-decorators - Using #provideFluent multiple times. However there is an issue with the example, so please see this issue: fluentProvide example needed. The above provideSingleton reflects the changes from that issue. Then you simply import the provideSingleton function from another file instead of defining it in the same like in the example.
Can anyone explain to me what I'm missing? Why oh why would certain exported items not bee seen as the type they are? Is there a step I'm not seeing that NodeJS takes to make the item actually exported and therefore different? Can I force the function to resolve as a function so it can be used as such?
ENV:
NodeJS: 10.9.0
Typescript: 3.0.1
Mac: 10.13.16
So it looks like you can get issues like this when NodeJS can't handle a recursive import. I'm not exactly sure how to check you are getting this error other than your symptoms are like what I stated above. Basically the recursion caused my function to not load and therefore undefined is not a function.
It would be easy to notice if you had code like so:
a.ts
import B from './b';
export default class A extends B {}
b.ts
import A from './a';
export default class B extends A {}
In my case, I think my function provideSingleton did not like the file I put it in because of some conflicting code in the file, which all I had was:
import {Container} from 'inversify';
import "reflect-metadata";
import {fluentProvide} from "inversify-binding-decorators";
const container = new Container();
function ProvideSingleton(identifier: any) {
return fluentProvide(identifier)
.inSingletonScope()
.done(true);
}
export {container, ProvideSingleton}
In the end, if this issue comes up, try another file for your function and pay good attention to how the order of the loading happens. Although NodeJS handles recursive imports most of the time, you can still trip it out.
I have several modules that export a function that return true or false when the payload is valid or not. I also have a config file in JSON in which I specify the name of the validator script to use depending on the payload type:
[
{
"boardVersion": "1",
"availableInterfaces": [
{ "name": "digital", "validator": "digitalV1" },
{ "name": "analog", "validator": "analogV1" },
]
}
]
And for example inside digitalv1.js I have something like:
import validator from 'validator';
module.exports = (value) => {
validator.isInt(value, {min: 0, max: 3});
};
And finally, a controller that gets the payload from ExpressJS and depending on the endpoint called it decides what validator to use. The thing now is how can I load the validator in the controller.
There are 2 approaches that come to my mind:
In the controller, I require every validator and push them in a key-value array (or object), in which the key is the name of the validator and the value the validator itself.
Instead of defining a validator name in the JSON file I could just put the file path in the file system and just require the file when I need it.
I there a better/cleaner way to approach this? Feel free to suggest even a different architecture. The idea though is to keep validators separated for code cleanness sake.
You can use option 1, but with a "barrel module", which imports the validators, and attaches them onto an array or object. Then, any module that needs the validators can just import the main module, and use the provided lookup function, index, or key to get the validator they need.
Be careful of circular dependencies: if you have them, you can use module.exports.x = and Node will handle them correctly (Note: I'm not sure if this is necessary with ES6 modules, which handle circular dependencies a little differently; just something to be on guard for).
Since the knowledge to create this "barrel module" already exists in your JSON, you could watch your JSON file in your build process, and automatically generate this barrel module if any of the file associations change, throw an error if a specified module is not found at a certain file path, etc.