ErrorSweep — Workspace-Wide TypeScript Error Aggregator for VS Code
You are 400 files deep in a TypeScript monorepo refactor and VS Code's Problems panel shows you exactly 1 file at a time like it is 2012. ErrorSweep is a VS Code extension that aggregates every TypeScript error across your entire workspace into a single searchable, filterable, severity-sorted panel — so you can see the full blast radius of a type change before you commit.
Difficulty
intermediate
Category
Developer Tools
Market Demand
High
Revenue Score
6/10
Platform
VS Code Extension
Vibe Code Friendly
No
Hackathon Score
6/10
Validated by Real Pain
— sourced from real community discussions
TypeScript developers on large codebases cannot see all errors across hundreds of files simultaneously in VS Code, forcing them to open each file individually or parse raw tsc terminal output to assess refactor impact.
What is it?
TypeScript's tsc --noEmit catches all errors but its terminal output is a wall of text. VS Code's native Problems panel only shows errors for files you have opened, making large refactors feel like defusing a bomb in the dark. ErrorSweep runs tsc in watch mode in a background process, parses all diagnostics, and surfaces them in a rich sidebar panel with filtering by severity, file path glob, and error code. Clicking an error opens the exact line. A 'refactor blast radius' view groups errors by the type that changed, so you can see 'this interface rename broke 47 usages in 12 files' at a glance. The extension ships as a .vsix file via the VS Code Marketplace. Buildable now because the VS Code Extension API for custom tree views is mature, and TypeScript's language server exposes programmatic diagnostic access via the typescript compiler API.
Why now?
TypeScript monorepo adoption accelerated sharply with the vibe-coding wave — AI-generated code produces large volumes of type errors that need triage at scale, and VS Code's native tooling has not kept up.
- ▸Workspace-wide TypeScript diagnostic aggregator running tsc in background watch mode, surfaced in a VS Code TreeView sidebar.
- ▸Severity filter, file path glob filter, and TS error code filter on the aggregated panel.
- ▸Blast radius view that groups errors by the source type or interface that changed.
- ▸One-click jump to exact file and line for any error in the panel.
Target Audience
TypeScript developers working on monorepos and large codebases — targeting the 12M+ VS Code users with TypeScript as their primary language.
Example Use Case
A senior engineer doing a monorepo-wide interface rename opens ErrorSweep, sees 47 errors grouped under the changed interface across 12 files sorted by severity, fixes them top-down, and ships the PR in 90 minutes instead of half a day of file-hopping.
User Stories
- ▸As a TypeScript engineer, I want to see all workspace errors in one panel without opening each file, so that I understand the full impact of a type change before committing.
- ▸As a senior dev doing a monorepo refactor, I want errors grouped by the interface I changed, so that I can triage and fix them in order without losing track.
- ▸As a team lead, I want to filter errors by file path glob, so that I can focus on my own module's errors without noise from dependencies.
Done When
- ✓Error aggregation: done when opening a TypeScript workspace with 50+ errors shows all of them in the ErrorSweep sidebar within 10 seconds without opening any files.
- ✓Blast radius view: done when renaming an interface causes a grouped view showing all affected files and error count under that interface name.
- ✓Click to navigate: done when clicking any error in the panel opens the exact file and highlights the exact line with the cursor.
- ✓License gate: done when a user without a Pro key sees the blast radius view locked with a clear upgrade prompt and link to the pricing page.
Is it worth building?
$9/month Pro x 500 users = $4,500 MRR at month 5. Math assumes 2% conversion from 25,000 Marketplace installs driven by dev Twitter and Hacker News. Conservative — extension discoverability is slow without a viral demo.
Unit Economics
CAC: $3 via organic Marketplace and Reddit. LTV: $108 (12 months at $9/month). Payback: immediate. Gross margin: 97%.
Business Model
Freemium one-time purchase
Monetization Path
Free tier: workspace error panel, unlimited file count. Pro at $9/month: blast radius grouping, glob filtering, Slack error digest export.
Revenue Timeline
First dollar: week 3 via Pro license. $1k MRR: month 4. $5k MRR: month 9.
Estimated Monthly Cost
Vercel: $0 (license validation serverless), Supabase: $0 (free tier for license records), Stripe fees: ~$15. Total: ~$15/month at launch.
Profit Potential
Side-income viable at $3k-$6k MRR with focused dev community distribution.
Scalability
Medium — add ESLint aggregation, multi-root workspace support, and a team error digest Slack bot as V2.
Success Metrics
Week 2: extension published on VS Code Marketplace. Month 1: 500 installs. Month 3: 100 Pro subscribers.
Launch & Validation Plan
Post a screen recording in r/typescript showing blast radius grouping on a real monorepo refactor — measure upvotes and comments before publishing to Marketplace.
Customer Acquisition Strategy
First customer: post screen recording on r/typescript and dev Twitter showing a 400-file monorepo refactor with blast radius view — offer Pro free for 6 months to first 20 commenters who install and review. Ongoing: VS Code Marketplace organic, Hacker News Show HN, TypeScript community Discord.
What's the competition?
Competition Level
Low
Similar Products
VS Code Problems panel (file-by-file only, no grouping), tsc CLI output (unfiltered wall of text), Error Lens extension (inline display, no aggregation) — ErrorSweep fills the workspace-level grouping gap.
Competitive Advantage
VS Code native Problems panel only shows open files — ErrorSweep shows the full workspace without opening files, plus blast radius grouping that no native tool offers.
Regulatory Risks
Low regulatory risk. VS Code Marketplace terms require compliance with extension publishing policies.
What's the roadmap?
Feature Roadmap
V1 (launch): workspace error panel, severity filter, blast radius grouping, line jump. V2 (month 2-3): file glob filter, error code filter, ESLint aggregation. V3 (month 4+): team Slack digest export, remote SSH workspace support.
Milestone Plan
Phase 1 (Week 1): TscWatcher, DiagnosticParser, and TreeView sidebar shipped. Phase 2 (Week 2): BlastRadiusGrouper, license gate, and Marketplace publish done. Phase 3 (Month 2): 500 installs and 50 Pro subscribers.
How do you build it?
Tech Stack
VS Code Extension API, TypeScript Compiler API for diagnostics, Node.js for tsc watch process, Stripe for Pro license — build with Cursor for extension logic.
Suggested Frameworks
VS Code Extension API, TypeScript Compiler API, vsce (VS Code Extension CLI)
Time to Ship
2 weeks
Required Skills
VS Code Extension API, TypeScript Compiler API diagnostics, TreeView provider, Node.js child process management.
Resources
VS Code Extension API docs, TypeScript Compiler API handbook, vsce publishing guide.
MVP Scope
src/extension.ts (activation + command registration), src/ErrorTreeProvider.ts (TreeView data provider), src/TscWatcher.ts (background tsc watch process manager), src/DiagnosticParser.ts (parse tsc output into typed errors), src/BlastRadiusGrouper.ts (group errors by changed type), src/LicenseGate.ts (Pro feature check), package.json (VS Code extension manifest), .vscodeignore, .env.example (LICENSE_KEY).
Core User Journey
Install extension -> open TypeScript workspace -> ErrorSweep sidebar populates all errors -> click blast radius view -> click error to jump to line -> fix and watch count drop in real time.
Architecture Pattern
Extension activates -> spawns tsc --watch child process -> parses stdout diagnostics -> DiagnosticParser normalises into typed errors -> BlastRadiusGrouper clusters by changed type -> ErrorTreeProvider renders TreeView -> click opens editor at exact line.
Data Model
Workspace has many Diagnostics. Diagnostic has file, line, column, message, errorCode, severity. BlastRadiusGroup has sourceType and many Diagnostics.
Integration Points
VS Code Extension API for sidebar and commands, TypeScript Compiler API for diagnostic access, Stripe for Pro license purchase, Supabase for license validation.
V1 Scope Boundaries
V1 excludes: ESLint aggregation, multi-root workspace, remote SSH workspace support, team error sharing, mobile.
Success Definition
A TypeScript developer discovers ErrorSweep on the Marketplace, installs it, sees their monorepo blast radius in under 30 seconds, and upgrades to Pro without any founder contact.
Challenges
The real distribution problem is that Ctrl+Shift+M already shows a filtered version of this — the blast radius grouping is the only truly differentiated feature, and the entire product pitch must lead with that, not the aggregation.
Avoid These Pitfalls
Do not ship without a working demo on a real large TypeScript repo — an empty panel on a small project is unconvincing. Do not over-build the UI before validating the blast radius grouping resonates — it is the only feature that justifies paying. First 10 paying users will come from the TypeScript subreddit demo post, not organic Marketplace search.
Security Requirements
License keys validated server-side via Supabase, no source code or diagnostics sent remotely, all processing local, Stripe webhook signature validated.
Infrastructure Plan
VS Code Marketplace for distribution, Supabase free tier for license records, Vercel serverless for license check API, GitHub Actions for vsce publish on release tag.
Performance Targets
Diagnostic panel populates under 10s for workspaces with up to 1000 errors. TreeView re-renders under 100ms on file save. License check API under 150ms. No DAU-based infrastructure concerns at launch.
Go-Live Checklist
- ☐Blast radius grouping tested on 3 real monorepos.
- ☐Stripe Pro license purchase tested end-to-end.
- ☐Sentry error tracking live on license API.
- ☐VS Code Marketplace listing approved.
- ☐Custom domain for landing page with SSL.
- ☐Privacy policy published.
- ☐5 beta users confirmed blast radius view works.
- ☐Rollback plan: unpublish Marketplace version, revert to previous release.
- ☐Demo screen recording posted to r/typescript and dev Twitter.
First Run Experience
On first run: the ErrorSweep sidebar activates immediately and begins populating errors from the open workspace using tsc in the background. No configuration required — if tsconfig.json exists, it works. Users with no TypeScript errors see a green panel with a count of 0 errors and a link to a demo repo with intentional errors to explore the blast radius view.
How to build it, step by step
1. Define Diagnostic type: file, line, column, errorCode, message, severity, sourceType. 2. Scaffold VS Code extension with vsce and TypeScript, register sidebar TreeView in package.json contributes. 3. Build TscWatcher that spawns tsc --watch --noEmit as a child process and streams stdout. 4. Build DiagnosticParser that parses tsc output lines into typed Diagnostic objects. 5. Build BlastRadiusGrouper that clusters Diagnostics by errorCode and inferred changed type. 6. Implement ErrorTreeProvider as a VS Code TreeDataProvider rendering severity groups and blast radius groups. 7. Add filter bar commands (by severity, by file glob, by error code) using VS Code QuickPick. 8. Build LicenseGate that validates a Pro license key against Supabase on extension activation. 9. Package and publish to VS Code Marketplace via vsce publish. 10. Verify: open a TypeScript monorepo with known errors, confirm all errors appear in sidebar grouped by severity, click one and confirm editor jumps to exact line.
Generated
May 10, 2026
Model
claude-sonnet-4-6
Disclaimer: Ideas on this site are AI-generated and may contain inaccuracies. Revenue estimates, market demand figures, and financial projections are illustrative assumptions only — not financial advice. Do your own research before making any business or investment decisions. Technology availability, pricing, and market conditions change rapidly; always verify details independently.