Demo 09 — Autofix & Diagnostics

Overview

VibeCody’s Autofix system detects and repairs code issues automatically. It integrates with LSP diagnostics (compiler errors, linter warnings, type errors) and uses AI to generate targeted fixes. You can fix a single diagnostic, batch-fix an entire file or project, or delegate to Cloud Autofix agents and BugBot for large-scale automated issue detection.

Prerequisites

VibeCody installed (vibecli --version returns 0.5.1+)
An AI provider configured in ~/.vibecli/config.toml
A project with at least one language server available (e.g., rust-analyzer for Rust, typescript-language-server for TypeScript)
For VibeUI: cd vibeui && npm install && npm run tauri dev

Step-by-Step Walkthrough

1. View Diagnostics

Open a file with errors or warnings. VibeCody’s LSP integration surfaces diagnostics in real time.

VibeUI:

Error and warning counts appear in the status bar
Squiggly underlines highlight issues in the editor
Open the Problems panel (Cmd+Shift+M) for a full list

CLI:

# Start the REPL
vibecli

# List diagnostics for the current project
/autofix list

Example output:

Diagnostics (14 issues in 6 files):

  ERROR  src/auth.rs:23:5      — E0308: mismatched types, expected `String` found `&str`
  ERROR  src/auth.rs:45:12     — E0599: no method named `to_json` found for struct `User`
  WARN   src/handler.rs:10:1   — unused import: `std::collections::HashMap`
  WARN   src/handler.rs:34:9   — variable `result` is never read
  ERROR  src/db.rs:67:20       — E0277: trait bound `Row: Serialize` not satisfied
  WARN   src/main.rs:5:5       — unused variable: `config`
  ...

2. Fix a Single Diagnostic

VibeUI:

Hover over an underlined error
Click the lightbulb icon or press Cmd+.
Select VibeCody: AI Fix from the quick actions menu
Review the proposed change in the diff overlay
Click Accept or press Cmd+Enter

CLI:

# Fix a specific diagnostic by file and line
/autofix fix src/auth.rs:23

# Or use the interactive selector
/autofix fix --interactive

Example output:

Fixing: E0308 at src/auth.rs:23:5 — mismatched types

AI Analysis:
  The function signature expects `String` but a `&str` literal is passed.
  Adding `.to_string()` converts the reference to an owned String.

Proposed fix:
  - let name = "admin";
  + let name = "admin".to_string();

Apply fix? [y/n/e(dit)]: y
Fixed: src/auth.rs:23

3. Batch Fix Across Files

Fix all diagnostics in a file or the entire project at once.

CLI:

# Fix all issues in a single file
/autofix fix src/auth.rs --all

# Fix all warnings across the project
/autofix fix --all --severity warn

# Fix all errors across the project
/autofix fix --all --severity error

# Dry run — show fixes without applying
/autofix fix --all --dry-run

Example output:

Batch autofix (dry run):

  [1/14] src/auth.rs:23     — E0308: .to_string() conversion          FIXABLE
  [2/14] src/auth.rs:45     — E0599: add `use serde_json::ToJson`     FIXABLE
  [3/14] src/handler.rs:10  — unused import: remove line               FIXABLE
  [4/14] src/handler.rs:34  — unused variable: prefix with `_`        FIXABLE
  [5/14] src/db.rs:67       — missing trait: derive Serialize          FIXABLE
  ...

  Fixable: 12/14 | Needs review: 2/14
  Run without --dry-run to apply.

VibeUI:

Open the Autofix panel (AI Panel > Autofix tab)
Click Scan Project
Review the list of detected issues with proposed fixes
Click Fix All or select individual fixes to apply
A diff view shows all changes before confirmation

4. AI-Powered Fix Suggestions

For non-trivial issues where a simple mechanical fix is not sufficient, VibeCody uses AI to analyze the broader context and propose a semantic fix.

# Get an AI analysis of a complex error
/autofix analyze src/db.rs:67

Example output:

AI Analysis for E0277 at src/db.rs:67:

The `Row` struct needs to implement `Serialize` for the JSON API response.
However, it contains a `chrono::NaiveDateTime` field which requires the
`chrono` crate's `serde` feature.

Recommended fix (2 changes):
  1. Cargo.toml: Change `chrono = "0.4"` to `chrono = { version = "0.4", features = ["serde"] }`
  2. src/db.rs: Add `#[derive(Serialize)]` to `struct Row`

Apply multi-file fix? [y/n]:

5. Cloud Autofix Agents

For large projects, offload autofix to cloud agents that run in sandboxed containers.

CLI:

# Launch a cloud autofix agent
/autofix cloud --scope "src/**/*.rs" --max-fixes 50

# Check agent status
/autofix cloud status

Example output:

Cloud Autofix Agent [agent-af-8c3d]:
  Status:     Running
  Scope:      src/**/*.rs (87 files)
  Progress:   34/87 files scanned
  Fixes:      12 applied, 3 pending review
  Runtime:    2m 14s
  Container:  vibecody-sandbox-af-8c3d

VibeUI:

In the Autofix panel, click Cloud Autofix
Configure the scope and max fixes
Click Launch Agent
Monitor progress in real time; review fixes as they arrive

6. BugBot Automated Issue Detection

BugBot proactively scans your codebase for potential bugs, security issues, and anti-patterns beyond what the compiler or linter detects.

CLI:

# Run a deep scan using the agent to find bugs beyond compiler diagnostics
vibecli --agent "Scan src/ for security issues: SQL injection, timing attacks, \
  unwrap on network results. Report findings with severity and suggested fixes."

Example agent output:

 ✓ Reading src/db.rs
 ✓ Reading src/auth.rs
 ✓ Reading src/handler.rs
 ✓ Searching: "unwrap"

Agent complete: Found 3 issues.

  HIGH   src/db.rs:34      SQL Injection: User input interpolated into query string
         Suggestion: Use parameterized query with `sqlx::query!` macro

  MEDIUM src/auth.rs:78    Timing Attack: String comparison on password hash
         Suggestion: Use `constant_time_eq` from the `subtle` crate

  LOW    src/handler.rs:92 Unwrap on network result: `.unwrap()` on HTTP response
         Suggestion: Replace with `?` operator or `.expect()` with message

To auto-fix all findings, use agent mode:

vibecli --agent "Fix the SQL injection in src/db.rs, timing attack in src/auth.rs, \
  and unwrap in src/handler.rs" --auto-edit

VibeUI:

Open the Autofix panel (AI Panel > Autofix tab)
Click Scan Project for compiler/linter diagnostics
For deeper analysis, use the AI chat to ask for a security review
Click Fix on individual findings or Fix All

Demo Recording

{
  "id": "demo-autofix",
  "title": "Autofix & Diagnostics",
  "description": "Demonstrates automated bug detection, LSP diagnostic integration, and AI-powered fix suggestions across single files and entire projects",
  "estimated_duration_s": 140,
  "steps": [
    {
      "action": "Navigate",
      "target": "vibeui://open?folder=/home/user/my-project"
    },
    {
      "action": "Narrate",
      "value": "We have a project with several compiler errors and warnings. Let's see how Autofix detects and repairs them."
    },
    {
      "action": "Click",
      "target": ".explorer-file[data-path='src/auth.rs']",
      "description": "Open auth.rs which has errors"
    },
    {
      "action": "Wait",
      "duration_ms": 1500
    },
    {
      "action": "Screenshot",
      "label": "file-with-errors"
    },
    {
      "action": "Assert",
      "target": ".status-bar .error-count",
      "value": "greater_than:0"
    },
    {
      "action": "Narrate",
      "value": "Red squiggles indicate compiler errors. Let's hover over one to see the diagnostic."
    },
    {
      "action": "Click",
      "target": ".editor-line:nth-child(23) .squiggly-error",
      "description": "Hover over the error on line 23"
    },
    {
      "action": "Wait",
      "duration_ms": 500
    },
    {
      "action": "Screenshot",
      "label": "error-hover-tooltip"
    },
    {
      "action": "Click",
      "target": ".lightbulb-icon",
      "description": "Click the lightbulb to see quick actions"
    },
    {
      "action": "Click",
      "target": ".quick-action[data-action='ai-fix']",
      "description": "Select AI Fix from quick actions"
    },
    {
      "action": "Wait",
      "duration_ms": 2000
    },
    {
      "action": "Screenshot",
      "label": "ai-fix-diff-overlay"
    },
    {
      "action": "Assert",
      "target": ".diff-overlay .added-line",
      "value": "contains:to_string"
    },
    {
      "action": "Type",
      "target": "keyboard",
      "value": "Cmd+Enter",
      "description": "Accept the fix"
    },
    {
      "action": "Narrate",
      "value": "Fix applied. Now let's batch-fix all remaining issues in the project."
    },
    {
      "action": "Click",
      "target": ".panel-tab[data-panel='autofix']",
      "description": "Open the Autofix panel"
    },
    {
      "action": "Click",
      "target": "#scan-project-btn",
      "description": "Scan the entire project"
    },
    {
      "action": "Wait",
      "duration_ms": 3000
    },
    {
      "action": "Screenshot",
      "label": "autofix-scan-results"
    },
    {
      "action": "Assert",
      "target": ".autofix-issue-list .issue",
      "value": "count_greater_than:5"
    },
    {
      "action": "Click",
      "target": "#fix-all-btn",
      "description": "Click Fix All to batch-apply fixes"
    },
    {
      "action": "Wait",
      "duration_ms": 4000
    },
    {
      "action": "Screenshot",
      "label": "batch-fix-diff-review"
    },
    {
      "action": "Click",
      "target": "#confirm-fixes-btn",
      "description": "Confirm all fixes after reviewing diffs"
    },
    {
      "action": "Narrate",
      "value": "All fixable issues resolved. Let's also run BugBot for proactive bug detection beyond compiler diagnostics."
    },
    {
      "action": "Click",
      "target": ".panel-tab[data-panel='bugbot']",
      "description": "Switch to BugBot panel"
    },
    {
      "action": "Click",
      "target": "#bugbot-scan-btn",
      "description": "Run BugBot scan"
    },
    {
      "action": "Wait",
      "duration_ms": 5000
    },
    {
      "action": "Screenshot",
      "label": "bugbot-findings"
    },
    {
      "action": "Assert",
      "target": ".bugbot-finding.severity-high",
      "value": "exists"
    },
    {
      "action": "Narrate",
      "value": "BugBot found a SQL injection vulnerability and a timing attack issue that no compiler or linter would catch. Each finding includes a one-click fix."
    },
    {
      "action": "Click",
      "target": ".bugbot-finding:first-child .fix-btn",
      "description": "Fix the highest-severity finding"
    },
    {
      "action": "Wait",
      "duration_ms": 2000
    },
    {
      "action": "Screenshot",
      "label": "bugbot-fix-applied"
    }
  ],
  "tags": ["autofix", "diagnostics", "lsp", "bugbot", "cloud-autofix", "batch-fix"]
}

What’s Next

Demo 10 — Code Transforms — Structural refactoring with AST-based transforms
Demo 08 — Code Search & Embeddings — Find code to fix with semantic search
Demo 11 — Docker & Container Management — Run autofix agents in sandboxed containers