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Alexander Liberov edited this page Oct 30, 2026 · 1 revision

vscode-extension

The drag-lint VS Code extension (editors\vscode\drag-lint) runs drag-lint lsp as the language server for Pascal files: hover, go-to-definition, references, completion, signature help and lint diagnostics in the Problems panel.

Commands

Open the Command Palette (Ctrl+Shift+P) and type drag-lint.

Command Use it when
drag-lint: Refresh Problems (dragLint.refreshProblems) Problems look stale. Re-lints, from disk, every file that currently shows a drag-lint problem. No restart, no reload. First thing to try.
drag-lint: Restart Language Server (dragLint.restartServer) Refresh did not help, the server crashed or latched into a failed state, or you changed dragLint.serverPath / dragLint.databases. Restarts the client and its engine process.
drag-lint: Update Engine Copy Now (dragLint.updateEngine) You rebuilt or redeployed the engine and want the extension's private engine copy refreshed now instead of on the next window start.
drag-lint: Apply RAD Studio Colours (Pascal only) (dragLint.applyRadStudioColours) You want Pascal files coloured like your RAD Studio editor. Instant, leaves other languages alone.
drag-lint: Generate Theme From RAD Studio Colours (dragLint.generateTheme) You changed your RAD Studio colour scheme and want the Delphi IDE (drag-lint) theme rebuilt. VS Code reads a theme once, so it offers a window reload.
drag-lint: Select Platform / Select Project (dragLint.selectPlatform, dragLint.selectProject) You want a different platform or project index to answer lookups. Also reachable from the status-bar context item.

Problems follow files edited on disk

The extension watches **/*.{pas,dpr,dpk,inc,dfm} (VS Code uses OS change notifications) and sends workspace/didChangeWatchedFiles to the server. For a .pas, .dpr or .dpk file that is not open in an editor, the server re-lints it from disk and publishes the result; a deleted file gets an empty diagnostics array. A file that is open is left alone: the editor buffer is authoritative, and VS Code sends didChange when it reloads the buffer.

  • Bursts are bounded: duplicates inside one message are dropped and at most 64 files are re-linted per message.
  • Nothing here reindexes the project. Lint findings follow the file at once; index-backed answers (hover, find-references) follow the next reindex.
  • drag-lint: Refresh Problems uses the custom notification draglint/refreshDiagnostics, which also refreshes open documents (using the live buffer).

Auto uses on save

VS Code runs editor.codeActionsOnSave on every save. The extension ships a default for Pascal files, so the uses clause adds what is missing without a click:

Code action kind Default What it does
source.addMissingImports on ("explicit") adds the unit that declares an undeclared name, but only when exactly one unit declares it. An ambiguous name (two or more units) is never applied silently; it stays a light-bulb quick fix.
source.removeUnusedImports off removes a dead uses entry (unused-unit-in-uses). Enable it in your settings: "[pascal]": { "editor.codeActionsOnSave": { "source.removeUnusedImports": "explicit" } }

Removal is gated. VS Code runs the save actions before the file reaches disk and before the index rescans it, so an ungated removal could delete the unit the code you just typed needs. The action is offered only when the buffer is identical to what the index last read AND the whole index is fresh. In practice a removal lands on the first save after the index has caught up with the buffer; a stale index, or an {$IFDEF} (any {$ directive) inside the uses clause, suppresses it. The light-bulb quick fix stays available in every case.

Never reported or removed: a unit with an initialization or finalization section, a unit declaring a class constructor or class destructor, and a unit instantiated by the form's .dfm -- they are linked for their side effect.

No while-typing mode. Half-typed names resolve to the wrong unit or none, and the index is never fresh mid-keystroke. The light bulb already works while typing.

Problems look stale

  1. Run drag-lint: Refresh Problems.
  2. Still wrong, or the server looks dead: drag-lint: Restart Language Server.
  3. Avoid Developer: Reload Window when Claude Code sessions run in that window: the reload ends them. Refresh Problems and Restart Language Server do not touch other extensions.

Guard: tests\autotest\run_lsp_watch_pascal_guard.ps1 (drives the LSP over stdio: Changed on a closed file with a finding publishes it, rewritten clean publishes an empty array, an open file and a non-source file publish nothing). Related guards: run_lsp_clear_diags_guard.ps1, run_vscode_extension_contract.ps1.

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