Palantír — Refactoring Risk Analyzer

"The palantíri were made so that those who had them could see far, and know the minds of men."
— J.R.R. Tolkien

Palantír is a VS Code extension that gives you the Blast Radius of any change — before you make it. It uses the Language Server Protocol (LSP) to analyze how many places in your codebase depend on a given method or function, and surfaces that information directly in your editor via CodeLens indicators above every method signature.

Stop guessing the impact of a refactoring. Let Palantír show you.

How It Works

Palantír hooks into VS Code's built-in LSP infrastructure. When you open a supported file, it:

Discovers all methods, functions, and constructors using DocumentSymbolProvider
Counts their references across the entire project using ReferenceProvider
Renders a risk indicator directly above each method signature via CodeLens

No external servers. No indexing step. No configuration required.

Risk Indicators

Each method gets a color-coded Blast Radius label:

Indicator	References	Meaning
🟢 Low Impact	< 5	Safe to refactor freely
🟠 Medium Impact	5 – 20	Review callers before changing
🔴 HIGH RISK	> 20	High coupling — proceed with caution

Click any CodeLens label to jump to all references instantly.

Framework-Aware Context Badges

Palantír understands the frameworks you work with and adds contextual badges alongside the risk indicator:

Spring Boot (Java)

Annotation	Badge
`@GetMapping`, `@PostMapping`, `@PutMapping`, `@DeleteMapping`, `@PatchMapping`	`[REST]`
`@RequestMapping`	`[REST]`
`@Scheduled`	`[Scheduler]`
`@EventListener`, `@TransactionalEventListener`	`[Event]`
`@Bean`	`[Bean]`
`@Transactional`	`[Transactional]`
`@Query`	`[Query]`
`@Around`, `@Before`, `@After`, `@AfterReturning`, `@AfterThrowing`	`[AOP]`

NestJS (TypeScript)

Decorator	Badge
`@Get()`, `@Post()`, `@Put()`, `@Delete()`, `@Patch()`	`[REST]`
`@MessagePattern()`, `@EventPattern()`	`[Microservice]`
`@SubscribeMessage()`	`[WebSocket]`
`@UseGuards()`, `@UseInterceptors()`, `@UsePipes()`	`[Guard/Pipe]`
`@CommandHandler()`, `@QueryHandler()`	`[CQRS]`

Angular (TypeScript)

Decorator / Pattern	Badge
`@HostListener()`	`[DOM Event]`
`ngOnInit`, `ngOnDestroy`, `ngOnChanges`, `ngAfterViewInit`	`[Lifecycle]`
`@ViewChild()`, `@ContentChild()`	`[View Hook]`
`createEffect()`	`[NgRx Effect]`

Flutter / Dart

Pattern	Badge
`build(BuildContext)`	`[Widget Build]`
`initState`, `dispose`, `didChangeDependencies`	`[Lifecycle]`
`@override`	`[override]`

Example output:

Palantir [REST]: 🟠 Medium Impact (9 refs)       ← @GetMapping Spring Boot endpoint
Palantir [Transactional]: 🔴 HIGH RISK (23 refs)  ← critical service method
Palantir [Lifecycle]: 🟢 Low Impact (1 refs)      ← ngOnInit Angular hook
Palantir [Widget Build]: 🟢 Low Impact (1 refs)   ← Flutter widget
Palantir: 🟢 Low Impact (2 refs)                  ← plain function, no framework

Supported Languages

Language	Supported	Notes
TypeScript	✅	Full support, NestJS & Angular aware
TypeScript React (`.tsx`)	✅
JavaScript	✅
JavaScript React (`.jsx`)	✅
Java	✅	Spring Boot aware — requires LSP extension
Dart	✅	Flutter lifecycle & widget aware

Required Extensions (Language Servers)

Palantír relies on VS Code's LSP to find symbols and count references. For most languages, VS Code handles this natively. Java is the exception — it requires the official language server to be installed.

Java — Required

Language Support for Java™ by Red Hat
Extension ID: redhat.java

Without this extension, Palantír cannot discover Java symbols or count references. The Red Hat extension provides the full Java Language Server that powers symbol resolution, reference lookup, and project indexing.

Recommended companion extensions for Spring Boot:

Extension	ID	Purpose
Spring Boot Extension Pack	`vmware.vscode-boot-dev-pack`	Full Spring tooling suite
Spring Boot Tools	`vmware.vscode-spring-boot`	Application properties & bean graph

TypeScript / JavaScript — Built-in ✅

No additional extensions required. VS Code ships with a native TypeScript Language Server.

Dart / Flutter — Required

Dart
Extension ID: Dart-Code.dart-code

This extension provides the Dart Analyzer, which powers symbol resolution and reference lookup for both Dart and Flutter projects.

Getting Started

Running in Development

Clone this repository
Install dependencies:
```
npm install
```
Start the build watcher:
```
npm run watch
```
Press F5 to launch the Extension Development Host
Open any supported file — CodeLens indicators will appear above each method

Installing from VSIX

npm run package

This generates a .vsix file. Install it via:

Extensions → ⋯ → Install from VSIX...

Architecture

src/
├── extension.ts          # Entry point — registers the CodeLens provider
├── PalantirProvider.ts   # Core CodeLens provider (symbol discovery + reference counting)
└── FrameworkDetector.ts  # Framework pattern matcher (badges via regex)

Component	Responsibility
`extension.ts`	Activates on supported languages, wires up the provider
`PalantirProvider.ts`	Implements `provideCodeLenses` (symbol scan) and `resolveCodeLens` (LSP reference query)
`FrameworkDetector.ts`	Scans the ~8 lines above each symbol for framework decorators/annotations

Requirements

VS Code ^1.100.0 (or any compatible fork)
Node.js >=18

Author

Kaxius — kaxiusapps.vercel.app

Built with 🔭 by Kaxius to help developers see further.