Realm-js: react native chrome debugger-ui: _constructor is not a function

[shamilsun]

Hello

i have issue when launch app with react native remote debugger (chrome)

blob:http://localhos…-af12390f2e7c:15184 this._constructor is not a function

the problem with realm, im sure coz then i do comment this block, app start fine with debugger-ui

package.json

{
"name": "111",
"version": "0.1.0",
"private": true,
"devDependencies": {
"@types/jest": "^22.2.3",
"@types/react": "^16.3.14",
"@types/react-native": "^0.55.14",
"@types/react-test-renderer": "^16.0.1",
"babel-preset-react-native-stage-0": "^1.0.1",
"jest": "^23.6.0",
"jest-react-native": "^18.0.0",
"react-native-scripts-ts": "1.15.0",
"react-native-typescript-transformer": "^1.2.3",
"react-test-renderer": "16.3.1",
"ts-jest": "^22.4.6",
"tslib": "^1.9.1",
"typescript": "^2.8.3"
},
"scripts": {
"start": "react-native start",
"android": "react-native run-android",
"ios": "react-native run-ios",
"test": "jest"
},
"jest": {
"globals": {
"ts-jest": {
"useBabelrc": true
}
},
"moduleFileExtensions": [
"ts",
"tsx",
"js",
"jsx",
"json",
"node"
],
"preset": "react-native",
"testMatch": [
"/__tests__//.[tj]s?(x)",
"/?(.)(spec|test).[tj]s?(x)"
],
"transform": {
"^.+\.tsx?$": "ts-jest"
}
},
"dependencies": {
"axios": "^0.19.0-beta.1",
"react": "^16.7.0-alpha.0",
"react-native": "~0.55.2",
"react-native-device-info": "^0.24.3",
"react-native-easy-grid": "^0.2.0",
"react-navigation": "^3.0.0-alpha.7",
"realm":"^2.19.0-rc.4",
"react-native-uuid":"^1.4.9"
}
}

code:

file1. export connection

import Realm from "realm";
import {rnInstallationSchema} from "./Installation/rnInstallationSchema";
export const realm = new Realm({schema: [rnInstallationSchema]});

file2.
import ... realm of course too

static async getIntallationUUID(callback?:(uuid:string)=>void) : string {
if (!realm.objects(rnInstallationSchema.schema.name).length) {
await realm.write(() => {
realm.create(rnInstallationSchema.schema.name, {
UUID: uuid.v4(),
});
})
}
let uuid=realm.objects(rnInstallationSchema.schema.name)[0].UUID;
return callback(uuid);
}

[shamilsun]

i use yarn

[liamjones]

I've been hitting this with 2.18.0 this morning, downgrading to 2.16.2 fixes it for me

[xhuanlee]

same with 2.17.0

[jwinky-ptx]

I'm experiencing this issue with 2.18.0 (React 16.6.0, react-native 0.57.4). Downgrading to 2.17.0 resolves the issue. I'm using yarn (tried 1.9.4 and 1.12.1). I have not tried 2.19.0 yet.

[v-ken]

same problem with 2.19.0

[xiaonull]

I've been hitting this with 2.19.0 this morning, downgrading to 2.17.0 fixes it for me

[xiaonull]

I've been hitting this with 2.19.0 this morning, downgrading to 2.17.0 fixes it for me

Make sure the version in your package.json and your-project\node_modules\realm\package.json is "2.17.0" by npm and yarn to install.

[SAnegondhi]

eeek!
I came face to face with this issue with realm 2.19.0. But When I try to add Version 2.17.0 (as suggested above) by yarn add [email protected] command, it fails with ... node-pre-gyp ERR! not ok Failed to execute 'node-gyp build --fallback-to-build...

Version 2.19.0 _still_ installs fine (Except for the pesky this._constructor not a function error.
I am assured by many that node pre gyp is a real pain to sort out. I am at an impasse. 2.19.0 installs fine but has bugs. 2.17.0 can't even be added
Environment
Mac OS Mojave 10.14.1
react: 16.6.0-alpha.8af6728
react-native: 0.57.4

[gohopo]

same with 2.19.0

[aymanblank]

I've commented out the line 80 from "node_modules\realm\lib\browser\index.js".

[80] //config = this._constructor(config);
[81] let schemas = typeof config == 'object' && config.schema;
[82] let constructors = schemas ? {} : null;

And now it works fine for me. I couldn't find any implementation for the function _constructor so I guess removing it won't do any side effects.

[v-ken]

Thanks. Quick and dirty temporary solution.

[hoang-rio]

Any solution here? Same in 2.19.1

[levic92]

In 2.20.0 the error is:
realmConstructor.Sync._initializeSyncManager is not a function

This line is causing an error while debugging in Chrome

https://github.com/realm/realm-js/blob/v2.20.0/lib/index.js#L152

if (realmConstructor.Sync) {
    if (context === 'node.js') {
      nodeRequire('./notifier')(realmConstructor);
      if (!realmConstructor.Worker) {
          Object.defineProperty(realmConstructor, 'Worker', {value: nodeRequire('./worker')});
      }
    }
    // PROBLEM HERE
    realmConstructor.Sync._initializeSyncManager(createUserAgentDescription());
}

When this line is commented out it loads fine while debugging in Chrome

[gogoku]

@levic92 Have you been able to find a solution for this

[MujtabaFR]

As @levic92 explained .. the problem was on line 152 of file node_modules\realm\lib\index.js

if (realmConstructor.Sync) {
    if (context === 'node.js') {
      nodeRequire('./notifier')(realmConstructor);
      if (!realmConstructor.Worker) {
          Object.defineProperty(realmConstructor, 'Worker', {value: nodeRequire('./worker')});
      }
    }
    ///// PROBLEM HERE /////
    realmConstructor.Sync._initializeSyncManager(createUserAgentDescription()); 
}

As the problem only happening when remote JS debugging is enabled .. so I made that line work only if not debugging ..

if (realmConstructor.Sync) {
    if (context === 'node.js') {
      nodeRequire('./notifier')(realmConstructor);
      if (!realmConstructor.Worker) {
          Object.defineProperty(realmConstructor, 'Worker', {value: nodeRequire('./worker')});
      }
    }
    ///// Check if remote JS debugging is disabled /////
    if ((typeof DedicatedWorkerGlobalScope) == 'undefined') {
      realmConstructor.Sync._initializeSyncManager(createUserAgentDescription());
    }
}

[HarikaSabbella]

@MujtabaFR Have you created a PR for this fix?

[MujtabaFR]

@HarikaSabbella I've just created a PR suggesting this fix

[kneth]

I believe it is fixed in https://github.com/realm/realm-js/issues/2128 and released in v2.21.0.

[realm-probot[bot]]

Hey - looks like you forgot to add a T:* label - could you please add one?