I find the unused property warning super useful in a lot of situations, but often I get an error in the following situation:
const hello = () => 'Hello world!';
module.exports = {
hello, // <-- saying this is unused
};
I see that you can turn this feature off, but I'd rather keep it.
Export is marked unused if the exported module is not imported anywhere.
To get rid of the issue, you need importing the module in a different file, like:
const { hello } = require("./hello")
Related
Hii everyone currently I'm using the following library
https://www.npmjs.com/package/react-native-biometrics
for my project but I stuck here when I'm trying to write the unit tests for it I have mocked the library like below
import ReactNativeBiometrics, { BiometryTypes } from 'react-native-biometrics';
jest.mock ('react-native-biometrics', () =>
{
class ReactNativeBiometrics {
constructor(){
}
isSensorAvailable() {
}
}
return ReactNativeBiometrics;
});
Now I'm trying to mock
BiometryTypes
but its not getting mocked anyone can give some idea how this can be mocked.
BiometryTypes is exported like below
export declare const BiometryTypes: {
TouchID: string;
FaceID: string;
Biometrics: string;
};
I tried like below but its not working
import { BiometryTypes } from 'react-native-biometrics';
import * as all from 'react-native-biometrics';
const TouchID = 'TouchID' ;
all.BiometryTypes = {
TouchID: TouchID,
FaceID: TouchID
};
You can combine named and default mocks in factory function:
jest.mock ('react-native-biometrics', () =>
{
class ReactNativeBiometrics {
......
}
return {
__esModule: true
default: ReactNativeBiometrics,
BiometryTypes: { TouchID: 'mock1', FaceID: 'mock2', .... } // static values
};
});
Jest docs clarify why this is necessary:
When using the factory parameter for an ES6 module with a default export, the __esModule: true property needs to be specified. This property is normally generated by Babel / TypeScript, but here it needs to be set manually. When importing a default export, it's an instruction to import the property named default from the export object
Beware! With this approach, object BiometryTypes will be mocked once and forever, while you probably want to test different variants of it. Maybe doMock and unmock could help to overcome this, but in my opinion much much more reliable is to create several .test.js files, each one would mock BiometryTypes in unique way(e.g. FaceID_and_TouchID.test.js, TouchID-only.test.js etc). jest.mock is quite magical because it's hoisted to the very top, using unmock/doMock may break if values have already caught by other modules or closures in the same module.
Consider the following code:
const router = useRouter()
await router.push({
name: 'NonExistingRoute', // no typescript error ):
})
A non existing route name was given, but no TypeScript error happens. Instead the issue will only be noticed on runtime. Any way to get a compile-time error on this?
Perhaps you could wrap this in a utility function that only accepts typed route strings
const router = useRouter()
export type NamedRoute = "login" | "logout" | "user-profile";
export async function goToNamedRoute(name: NamedRoute): Promise<void> {
return router.push({name});
}
In short no.
For a compile error to exist there would need to be something explicitly wrong with the code, referencing an non-existent file, syntax error, etc.
It does sound like you are trying to solve some other issue here...i.e. why do you have the names of non-existing routes in your app?
In any case, perhaps you can avoid your errors programmatically, e.g.
let r = router.resolve({name: 'NonExistingRoute'});
if (r.resolved.matched.length > 0){
// exists
} else {
// doesn't exist
}
If you want to rely on Typescript for detecting wrong routes you might just use enums or closed types maybe?, although that will surely require some composition. Probably one way to go could be:
enum Cities {
NY,
London
}
function routeCreator(city: Cities, restOfPath?: string){
//combine paths somehow, e.g.
if(!restOfPath) return `/${Cities[city]}/`;
return `/${Cities[city]}/${restOfPath}`
}
I cannot give too much information here (because there really isn't), but only this:
All of the sudden, after adding a #Method function to a stencil component:
#Method()
async setMenuItems(items: Element[]): Promise<void> {
// code here
}
the component stopped compiling with the following - really unhelpful - error:
[ ERROR ] ./src/components/menu-content/menu-content.tsx:63:44
build error
L62: #Method()
L63: async setMenuItems(elements: Element[]): Promise<void> {
L64: const unsupportedChildren = elements.filter(e => !this.isSupportedChild(e)).map(e => e.tagName);
[12:37.1] build failed in 7.02 s
Things to notice
the return type Promise<void> inside the error-message is highlighted red
there are other #Methods that do work within this component (even with the same return type).
the "broken" #Method is structurally equal to those that do work.
TypeScript compiler does not complain about anything
Only stencil compiler fails
I already tried...
to google for this issue - did not find any hints to this problem
to remove the async and add return Promise.resolve()
to rename the method (I mean.. why not)
to move the method to another place in class
to remove the whole method (compiles fine x( )
to remove the #Method decorator (compiled, but of course my method is removed from API)
to delete node_modules folder and reinstall
I remember that I already had this error once, and apparently I somehow fixed it (or not, idk). But if I did, I cannot remember how.
Does anyone have an idea how to debug this - or even better fix?
I figured it out. A more complete version of my component is:
import { Element, ... } from '#stencil/core';
class MenuContent {
#Element() element: MenuContentElement;
#Method()
setMenuItems(elements: Element[]): Promise<void> {
// ------------------^^^^^^^
// Element is meant to be the built-in browser interface for Element
// but stencil thinks that this is the imported Element from '#stencil/core'!
}
}
The exact problem here is, that the stencil-compiler seems to assume that the elements parameter is of type Element that is imported from #stencil/core which is obviously wrong and leads to this strange unhelpful error.
Possible Solutions
1. Use an alias type for the built-in Element type
// types.ts
export type DomElement = Element;
// menu-content.tsx
import { DomElement } from './types';
...
async setMenuItems(elements: DomElement[]): Promise<void> { ... }
2. Switch to HTMLElement
Note: This is only legit, when you don't need to support other Element-types such as SVGElements for example!
async setMenuItems(elements: HTMLElement[]): Promise<void> { ... }
3. Use alias in import statement
Please note: When using #stencil eslint rules, they will complain about your renamed import and say that "own class members are not allowed to be public".
I created a ticket for it here: https://github.com/ionic-team/stencil-eslint/issues/28
import { Element as ElementDecorator} from '#stencil/core';
class MenuContent {
// eslint will complain about that:
// "Own class properties cannot be public."
#ElementDecorator() element: HTMLMenuContentElement;
}
I experienced this same issue not with the Element type but with the Event type, so it appears to be rooted deeper - also about a year after you reported this issue it seems to still be a problem with Stencil
I know you're not supposed to do this, but I'm trying to write some tests with legacy code still using requirejs that have a few window variables floating around.
Basically I'm trying to write a mocha test and include some predefined global variables that a different file would use later. I'm trying to do the following, but it seems the global variable "container" isn't populated when accessing it later.
global.document = require('jsdom').jsdom('<html></html>');
global.window = document.defaultView;
global.$ = require('jquery')(window);
// this should be available everywhere as far as I can tell...
global.container= {};
global.window.container= global.container;
// legacy scripts still using requirejs, so we need to load the require config here
var requirejs = require('testing-setup').requirejs;
// chai is nice
require('chai').should();
describe('model tests', function () {
var model;
// before we begin the tests, we need to require in all the necessary modules
before(function (done) {
window.container= {
dateFormat: false
};
requirejs(['Model', 'common', 'date'], function (Model) {
// load some dummy data out of a file
model= new Model(require('./test-data.js').item);
done();
});
});
// run some more tests down here, I'll spare you those
});
The script being loaded called "common" above has a reference to the global "container" object that lives on the window. Apparently what I have is not correct. Is there no way to set up a shared global variable in jsdom? I know it's not the standard way of doing things, so please spare the lectures. Refactoring all that legacy code right now is not really a feasible option.
Ah, it turns out this is the correct way of doing it. It appears the jsdom/nodejs differentiate the difference between window and global. If you want something to be available everywhere in every file in that session, it needs to be on the global namespace. The window is explicitly window.
I'm doing an experiment with wxWebConnect test application, incorporating the xpcom tutorial at "http://nerdlife.net/building-a-c-xpcom-component-in-windows/"
I adapt MyComponent class as necessary to compile together with testapp.exe (not as separate dll), and on MyApp::OnInit I have the following lines:
ns_smartptr<nsIComponentRegistrar> comp_reg;
res = NS_GetComponentRegistrar(&comp_reg.p);
if (NS_FAILED(res))
return false;
ns_smartptr<nsIFactory> prompt_factory;
CreateMyComponentFactory(&prompt_factory.p);
nsCID prompt_cid = MYCOMPONENT_CID;
res = comp_reg->RegisterFactory(prompt_cid,
"MyComponent",
"#mozilla.org/mycomp;1",
prompt_factory);
Those lines are copied from GeckoEngine::Init(), using the same mechanism to register PromptService, etc. The code compiles well and testapp.exe is running as expected.
I put javascript test as below :
try {
netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
const cid = "#mozilla.org/mycomp;1";
obj = Components.classes[cid].createInstance();
alert(typeof obj);
// bind the instance we just created to our interface
alert(Components.interfaces.nsIMyComponent);
obj = obj.QueryInterface(Components.interfaces.nsIMyComponent);
} catch (err) {
alert(err);
return;
}
and get the following exception:
Could not convert JavaScript argument arg 0 [nsISupport.QueryInterface]
The first alert says "object", so the line
Components.classes[cid].createInstance()
is returning the created instance.
The second alert says "undefined", so the interface nsIMyComponent is not recognized by XULRunner.
How to dynamically registering nsIMyComponent interface in wxWebConnect environment ?
Thx
I'm not sure what is happening here. The first thing I would check is that your component is scriptable (I assume it is, since the demo you copy from is). The next thing I would check is whether you can instantiate other, standard XULRunner components and get their interface (try something like "alert('Components.interfaces.nsIFile');" - at least in my version of wxWebConnect this shows an alert box with string "nsIFile".
Also, I think it would be worth checking the Error Console to make sure there are no errors or warnings reported. A magic string to do that (in Javascript) is:
window.open('chrome://global/content/console.xul', '', 'chrome,dialog=no,toolbar,resizable');