LSP Diagnostics

The Rulebound LSP server produces two types of diagnostics: AST-based diagnostics with precise source locations, and rule-based diagnostics from semantic validation.

AST Diagnostics

AST diagnostics have precise line and column ranges based on the tree-sitter parse tree. They appear as inline squiggly underlines in your editor.

src/auth.ts:5:3 [error] [ts-no-eval] eval() is a security risk and should never be used
src/auth.ts:8:1 [warning] [ts-no-console-log] Remove console.log before committing. Use a structured logger.

Each AST diagnostic includes:

Field	Description
Range	Exact start/end position (line, column)
Severity	Error, Warning, or Information
Source	Always `rulebound`
Message	Format: `[queryId] description`

Severity Mapping

Rule Severity	LSP Severity	Editor Display
`error`	Error	Red underline
`warning`	Warning	Yellow underline
`info`	Information	Blue underline

Rule Diagnostics

Rule diagnostics come from semantic validation against your project rules. Since semantic validation operates on the entire file, these diagnostics appear at line 0, column 0 (the beginning of the file).

src/service.ts:1:1 [warning] [Use Constructor Injection] Field injection detected (Fix: Use constructor injection with final fields)

Rule diagnostics include a suggested fix when available:

Field	Description
Range	Start of file (0:0 to 0:0)
Severity	Based on rule severity
Source	Always `rulebound`
Message	Format: `[ruleTitle] reason (Fix: suggestedFix)`

Analysis Triggers

Event	Behavior
File Opened	Immediate full analysis
Content Changed	Debounced analysis (300ms delay)
File Saved	Immediate full analysis (cancels pending debounce)

The debounce ensures analysis does not run on every keystroke. When you stop typing for 300ms, the analysis runs. Saving always triggers an immediate analysis.

Supported Languages

The LSP server detects language from file extensions:

Extensions	Language
`.ts`, `.tsx`	TypeScript
`.js`, `.jsx`, `.mjs`, `.cjs`	JavaScript
`.py`	Python
`.java`	Java
`.go`	Go
`.rs`	Rust
`.cs`	C#
`.cpp`, `.cc`, `.cxx`, `.h`, `.hpp`	C++
`.rb`	Ruby
`.sh`, `.bash`	Bash

Files with unsupported extensions are silently skipped (no diagnostics produced).

Troubleshooting

No diagnostics appearing:

Verify the LSP server is running: check your editor's LSP log
Ensure the file type is supported (see table above)
Check that .rulebound/rules/ exists in your workspace for rule diagnostics

Diagnostics are slow:

AST parsing is fast (<50ms for typical files)
Semantic validation may take longer for many rules
The 300ms debounce prevents redundant analysis

Diagnostics at wrong location:

AST diagnostics have precise locations
Rule diagnostics always appear at file start (this is expected)