This repository was archived by the owner on Nov 21, 2025. It is now read-only.
This repository was archived by the owner on Nov 21, 2025. It is now read-only.
Language server crash on duplicate decorated properties #2091
Description
🐞 bug report
Is this a regression?
This bug does not appear to be a regression from v18.0.0
Description
The language server crashes with an assertion of "Expected successfully analyzed compilation" when a duplicate decorated property is found in a component.
import { Component, Input } from '@angular/core';
import { RouterOutlet } from '@angular/router';
@Component({
selector: 'app-root',
standalone: true,
imports: [RouterOutlet],
templateUrl: './app.component.html',
styleUrl: './app.component.css',
})
export class AppComponent {
@Input({ required: true }) message: string = '';
@Input({ required: true }) error: boolean = false;
@Input({ required: true }) error: boolean = false;
}
Bug Type
What does this bug affect
- Angular Language Service VSCode extension
- Angular Language Service server
Reproduction
Steps to reproduce the behavior:
- Create a component with two
@Inputproperties using the same name - (in VSCode) Save the file to execute a check
- See error
Expected behavior
The language server flags the error in the code and continues running without triggering assertions and restarting.
Logs
The Angular Language Service debug-level log did not indicate any error before getting cleared on every restart. Below is the output of the Angular Language Service provided by the Output VSCode tab
[Info - 12:41:32 PM] Angular language server process ID: 60819
[Info - 12:41:32 PM] Imported typescript/lib/tsserverlibrary is version 5.5.3.
[Info - 12:41:32 PM] Using @angular/language-service v18.2.0-rc.0 from /Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/index.js
[Info - 12:41:32 PM] Log file: /Users/saren/Library/Application Support/Code/logs/20241003T115223/window3/exthost/Angular.ng-template/nglangsvc.log
[Info - 12:41:33 PM] Enabling language service for /Users/saren/test/crash/tsconfig.json.
/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:41043
throw new Error(`Duplicate decorated properties found on class '${clazz.name.text}': ` +
^
Error: Duplicate decorated properties found on class 'AppComponent': error
at extractClassMetadata (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:41043:19)
at ComponentDecoratorHandler.analyze (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:54554:27)
at TraitCompiler.analyzeTrait (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:38124:40)
at analyze (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:38090:44)
at TraitCompiler.analyzeClass (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:38112:21)
at visit (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:37889:26)
at visitNodes (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/typescript/lib/typescript.js:31715:22)
at forEachChildInSourceFile (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/typescript/lib/typescript.js:31928:12)
at Object.forEachChild (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/typescript/lib/typescript.js:32228:35)
at visit (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:37891:40)
Node.js v20.15.1
[Info - 12:41:48 PM] Connection to server got closed. Server will restart.
[Info - 12:41:48 PM] Angular language server process ID: 60925
[Info - 12:41:48 PM] Imported typescript/lib/tsserverlibrary is version 5.5.3.
[Info - 12:41:48 PM] Using @angular/language-service v18.2.0-rc.0 from /Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/index.js
[Info - 12:41:48 PM] Log file: /Users/saren/Library/Application Support/Code/logs/20241003T115223/window3/exthost/Angular.ng-template/nglangsvc.log
[Info - 12:41:49 PM] Enabling language service for /Users/saren/test/crash/tsconfig.json.
[Error - 12:41:50 PM] Request textDocument/foldingRange failed.
Message: Request textDocument/foldingRange failed with message: Duplicate decorated properties found on class 'AppComponent': error
Code: -32603
/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:58296
throw new Error(`AssertionError: Expected successfully analyzed compilation.`);
^
Error: AssertionError: Expected successfully analyzed compilation.
at IncrementalCompilation.priorTypeCheckingResultsFor (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:58296:23)
at TemplateTypeCheckerImpl.maybeAdoptPriorResultsForFile (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:53624:53)
at /Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:53657:22
at DelegatingPerfRecorder.inPhase (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:37692:24)
at TemplateTypeCheckerImpl.ensureAllShimsForOneFile (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:53656:23)
at TemplateTypeCheckerImpl.getDiagnosticsForFile (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:53494:26)
at NgCompiler.getTemplateDiagnosticsForFile (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:63533:69)
at NgCompiler.getDiagnosticsForFile (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:63089:42)
at /Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:69171:56
at /Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:69488:71
Node.js v20.15.1
[Info - 12:41:50 PM] Connection to server got closed. Server will restart.
[Info - 12:41:51 PM] Angular language server process ID: 60950
[Info - 12:41:51 PM] Imported typescript/lib/tsserverlibrary is version 5.5.3.
[Info - 12:41:51 PM] Using @angular/language-service v18.2.0-rc.0 from /Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/index.js
[Info - 12:41:51 PM] Log file: /Users/saren/Library/Application Support/Code/logs/20241003T115223/window3/exthost/Angular.ng-template/nglangsvc.log
[Info - 12:41:51 PM] Enabling language service for /Users/saren/test/crash/tsconfig.json.
[Error - 12:41:51 PM] Request textDocument/foldingRange failed.
Message: Request textDocument/foldingRange failed with message: Duplicate decorated properties found on class 'AppComponent': error
Code: -32603
[Error - 12:42:12 PM] Request textDocument/foldingRange failed.
Message: Request textDocument/foldingRange failed with message: Duplicate decorated properties found on class 'AppComponent': error
Code: -32603
/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:58296
throw new Error(`AssertionError: Expected successfully analyzed compilation.`);
^
Error: AssertionError: Expected successfully analyzed compilation.
at IncrementalCompilation.priorTypeCheckingResultsFor (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:58296:23)
at TemplateTypeCheckerImpl.maybeAdoptPriorResultsForFile (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:53624:53)
at /Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:53657:22
at DelegatingPerfRecorder.inPhase (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:37692:24)
at TemplateTypeCheckerImpl.ensureAllShimsForOneFile (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:53656:23)
at TemplateTypeCheckerImpl.getDiagnosticsForFile (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:53494:26)
at NgCompiler.getTemplateDiagnosticsForFile (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:63533:69)
at NgCompiler.getDiagnosticsForFile (/Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:63089:42)
at /Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:69171:56
at /Users/saren/.vscode/extensions/angular.ng-template-18.2.0/node_modules/@angular/language-service/bundles/language-service.js:69488:71
🌍 Your Environment
Angular Version:
Angular CLI: 18.2.7
Node: 22.9.0
Package Manager: npm 10.8.3
OS: darwin arm64
Angular: 18.2.7
... animations, cli, common, compiler, compiler-cli, core, forms
... platform-browser, platform-browser-dynamic, router
Package Version
---------------------------------------------------------
@angular-devkit/architect 0.1802.7
@angular-devkit/build-angular 18.2.7
@angular-devkit/core 18.2.7
@angular-devkit/schematics 18.2.7
@schematics/angular 18.2.7
rxjs 7.8.1
typescript 5.5.4
zone.js 0.14.10
Extension Version:
v18.2.0
VSCode Version:
Version: 1.93.1
Commit: 38c31bc77e0dd6ae88a4e9cc93428cc27a56ba40
Date: 2024-09-11T17:20:05.685Z
Electron: 30.4.0
ElectronBuildId: 10073054
Chromium: 124.0.6367.243
Node.js: 20.15.1
V8: 12.4.254.20-electron.0
OS: Darwin arm64 24.0.0
Operating System:
MacOS 15.0 (24A335)
Extension options:
"angular.log": "verbose"