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Editor Integration (t-linter)

t-linter is a linter, formatter, and LSP server for Python template strings (PEP 750 t-strings). It uses the same Rust parser (tstring-html-rs, tstring-thtml-rs) as this project for check and format operations.

Installation

pip install t-linter

Or with uv:

uv add t-linter

CLI usage

Check templates for errors

Validate t-string templates in your Python files:

t-linter check file.py
t-linter check src/

Output format options:

t-linter check file.py --format human    # default, human-readable
t-linter check file.py --format json     # machine-readable JSON
t-linter check file.py --format github   # GitHub Actions annotations

Use --error-on-issues to fail CI when problems are found:

t-linter check src/ --error-on-issues

Format templates

Canonical formatting for HTML and T-HTML template literals:

t-linter format file.py
t-linter format src/

Dry-run to see what would change without modifying files:

t-linter format --check file.py

LSP server

Start the built-in LSP server for real-time editor diagnostics and formatting:

t-linter lsp

The LSP provides:

  • Diagnostics — syntax and semantic errors reported inline as you type
  • Formatting — format-on-save or format-on-demand via your editor's formatting command

VSCode integration

  1. Install the binary:

    pip install t-linter

  2. Install the t-linter extension from the VSCode marketplace.

  3. Recommended: set "python.languageServer": "None" in VSCode settings to avoid conflicts with other Python language servers.

  4. Optionally configure t-linter.serverPath in settings if the binary is not on your PATH.

Other editors

Any editor that supports the Language Server Protocol can use t-linter lsp. Configure your editor to start t-linter lsp as the language server for Python files.

Configuration

Configure t-linter via pyproject.toml:

[tool.t-linter]
extend-exclude = ["generated", "vendor"]
ignore-file = ".t-linterignore"

How it works with tstring-html

t-linter and tstring-html share the same Rust parsing and formatting backends:

  • tstring-html is the runtime library — render_html() and html() parse and render templates at runtime
  • t-linter is the developer tooling — check validates templates and format canonicalizes them at development time

The integration seam is:

  • Backend Rust APIs accept tstring_syntax::TemplateInput
  • Diagnostics use tstring_syntax::SourceSpan
  • Tooling constructs TemplateInput from source text and preserves raw_source
  • No Python runtime object is required for lint/format
  • Reserved language ids: "html" and "thtml"