The reason for the error was a circular dependency in my code, where:

• Module X depends on Module Y
• Module Y depends on Module Z
• Module Z depends back on Module X

Once I resolved this circular dependency, the error was successfully fixed.

If you're looking to uncover circular dependencies within your codebase, try running this command:

npx madge --circular --extensions ts ./

Make sure to build before executing the command.

It's important to recognize that this issue may arise from having two public @Injectable classes defined in the same .ts file.

I have encountered this problem multiple times while testing out ideas locally, especially when breaking down one service into several others.

If you're looking for a quick solution and don't want to mess around with thetsconfig.json file on a large project, setting emitDecoratorMetadata: false can resolve this issue. However, simply moving one of the classes into a new file may also do the trick if you're pressed for time or prefer not to make changes to the configuration file.

The issue arose because of the sequence of my import statements within the module. I had to import a file that used the component before importing the actual component itself.

It appears that in the year 2023, there is no correct answer provided for this issue. However, this problem ranks high on Google search results. In essence, the solution involves the following scenario:

• A is injected with B
• B is injected with C
• C is injected with A

To tackle this issue, all three components need to be placed in a separate module.ts file, named abc.module.ts. Within this file, you can simplify matters by placing all components in an array as follows:

export const components = [ AComponent, BComponent, CComponent, ];

Subsequently, within the @NgModule {}, add this array to the following:

exports: [components], declarations: [components],

The imports:[] array should contain all dependent components required by these three. By following these steps, you will avoid encountering the error message:

ReferenceError : Cannot access 'X' before initialization

Avoiding circular dependencies is crucial!

It leads to an unsolvable loop of dependencies that the compiler cannot resolve. Oftentimes, it results in errors that make it seem like certain classes are not being imported at all.

While some believe circular dependencies should only be prevented in services and modules, they should actually be avoided across all elements, including models, components, and classes.

When faced with a circular dependency, it indicates that a code refactoring or restructuring is needed in the near future. The following strategies can help mitigate this issue when aiming to eliminate the circular dependency between two classes: A and B.

Solution 1: Union/Merge

A and B share a similar concept and can be merged into a single class.

Solution 2: Separation/Creation

Introducing a new class C that both A and B rely on, acting as an intermediary between the two.

In my experience, circular dependencies often occur when developers try to consolidate n logics into k (where k < n) classes.

Encountered a problem in Angular 8 due to declaring entryComponents as an empty array in a SharedModule:

entryComponents: []

Resolved the issue by removing the entryComponents declaration.

If you've landed here from a search: Encounter the error in Angular 15 or higher? It could be caused by circular dependencies within standalone components. A solution is to utilize forwardRef:

@Component({
  standalone: true,
  selector: 'app-b',
  templateUrl: './b.component.html',
  styleUrls: ['./b.scss'],
  imports: [
    forwardRef(() => AComponent))
  ]
})
export class BComponent implements OnInit {

}

Check out:

In my situation, there was a main.js file that was exporting functions from file1.js and file2.js.

file2.js was attempting to import from main.js instead of file1.js.

This caused the code to be processed in the wrong sequence due to the circular dependency:

file2.js -> main.js -> file2.js

To avoid this issue, it's advised to look for imports that end with from ".". Using an underscored prefix like _main.js (except in the root directory) can help prevent this problem.

I'm sharing this information for anyone else experiencing issues with

Cannot access 'X' before initialization

In my situation, the issue was not a circular dependency but rather a bug in an array that I exported and utilized within one of the components.

This array is multidimensional, and I mistakenly accessed one of its indexes without initializing it first, leading to the following error when I launched the project:

ReferenceError: Cannot access 'XXXModule' before initialization

I had to systematically revert files back one by one until pinpointing the exact problem. It's quite strange how there wasn't another error indicating the misuse of the array.

If you're struggling to fix this error, I recently discovered that having duplicate imports in both a Parent Component and Child Component caused this issue 😔.

Here's an example:

Both the ParentComponent and ChildComponent contain the same import statement:

import { ExampleComponent } from '../example-component/example-component.component'

The solution was simple - I just had to remove one of those import lines from either the Parent or Child component and the error went away.

I hope this helps someone save some time!

While working on expanding a library by adding a new folder/entry point, I encountered an issue that required my attention. Within the project, there were multiple components being imported into one another. The problem arose when VSCode defaulted to using the import path ./public-api. Fortunately, rectifying this by changing it to the correct component path (../newfolder/filename) successfully resolved the issue.

What I found challenging was encountering a Service with incorrect providedIn configuration. It seemed that my approach to providing and importing the service was flawed in either the component itself or another part of the application. Ultimately, I realized that I only required one instance at the root level, so reverting providedIn back to 'root' resolved the issue.

After investigating for any circular dependency and finding none in my somewhat bare project, I stumbled upon a solution by including the following line:

import 'reflect-metadata'

in the polyfills.ts file to resolve the issue.

The reason behind this fix eludes me, perhaps enlightening comments will provide clarity.