@jsvision/code-editor

A terminal-native source-code editor for JSVision applications. It provides an editor window—not an IDE—and has no browser or DOM dependency.

Quick start

import { CodeEditorWindow, createCodeEditorController, createDocumentModel } from '@jsvision/code-editor';

const document = createDocumentModel({
  uri: 'file:///workspace/main.ts',
  languageId: 'typescript',
  text: 'const answer: number = 42;\n',
});
const controller = createCodeEditorController({
  document,
  host: async (effect) => {
    // Save, close, navigation, commands, and cross-document edits stay host-owned.
    console.log(effect.kind);
    return true;
  },
});
const window = new CodeEditorWindow({ controller, title: 'main.ts' });

Internationalization

Import one explicit locale catalog, create one application-owned service, and pass the same service to the application and editor:

import { codeEditorNl } from '@jsvision/code-editor/locales/nl';
import { createI18n, defineCatalog } from '@jsvision/i18n';

const appOverrides = defineCatalog({
  schema: 1,
  locale: 'nl',
  messages: { 'code-editor.window.title': 'Broneditor' },
});
const i18n = createI18n({ locale: 'nl', catalogs: [codeEditorNl, appOverrides] });
const localizedWindow = new CodeEditorWindow({ controller, i18n });

The application catalog comes last so its messages win. Without injection, each CodeEditor creates an isolated English service for compatibility. Editor-owned labels are translated; source, queries and replacement values, language IDs, filenames, paths, key/command tokens, and LSP or host-provided detail remain caller content and are sanitized only for terminal-safe presentation.

The root entry point includes the document model, controller, CodeEditor, CodeEditorWindow, themes, protocol-neutral LSP coordination, safety limits, degradation state, and observability. Built-in adapters are separate public imports:

• @jsvision/code-editor/languages/javascript
• @jsvision/code-editor/languages/typescript
• @jsvision/code-editor/languages/postgresql
• @jsvision/code-editor/node for the optional Node JSON-RPC process transport

Language services and safety

The editor uses the industry-standard Language Server Protocol through a transport-neutral CodeEditorLspSession. Applications may provide an in-process session or use the Node transport. Filesystem writes, commands, cross-document edits, navigation, save, and close remain explicit host effects; the editor never silently owns those operations.

All document, protocol, completion, diagnostic, decoration, history, and telemetry collections have hard limits. Oversized or malformed results are rejected or truncated and reported through the degradation and observability APIs. Source text is projected into terminal cells, so terminal control bytes are displayed safely instead of being written to the terminal.

Themes and terminal capabilities

The hybrid theme model supports application-derived colors, editor overrides, and independent dark, light, and classic palettes. Semantic roles remain stable while colors change. Monochrome, ASCII, narrow-terminal, diagnostic, selection, pending, read-only, and degraded states retain non-color indicators.

Viewport and input

CodeEditorWindow keeps the editor, status line, and passive horizontal and vertical scrollbars synchronized as the terminal resizes or the document changes. Typing and caret navigation reveal the active caret with the smallest required scroll, while an explicit wheel or scrollbar movement remains in place until the next editing or navigation action.

The editor supports primary-button caret placement, captured drag selection, edge auto-scroll, double-click selection for Unicode identifier and punctuation runs, three-cell wheel scrolling, and the modern keyboard actions documented by the standalone kitchen sink. Ctrl+/ toggles the built-in line-comment delimiter for JavaScript, TypeScript, and PostgreSQL; unsupported languages leave the document unchanged.

Parser-provided multi-line folds can be collapsed with fold, unfold, foldAll, unfoldAll, or toggleFold. Collapsing is presentation-only: source, revision, modified state, and undo history do not change. Keyboard and mouse navigation, caret following, line numbers, and scrollbar ranges all skip hidden rows. Enable lineNumbers to show clickable Unicode fold markers; ASCII and monochrome terminals receive equivalent non-color markers. Stale or malformed parser ranges never hide source.

Window geometry is synchronized for drag-resize, maximize, restore, terminal resize while maximized, cascade, and tile. Moving a window changes its origin without changing the editor's interior dimensions.

For standalone composition, CodeEditor.resizeViewport(width, height) allows a host to publish new terminal-cell dimensions before drawing. viewportMetrics exposes immutable current geometry and clamped scroll limits for custom passive chrome.

Standalone kitchen sink

Run the comprehensive, deterministic example:

yarn workspace @jsvision/examples demo:code-editor

It includes direct and windowed editors, real structural folding, a capability-level inventory, editing and read-only lifecycle, SQL/JavaScript/TypeScript/plain text, local parsing, simulated LSP intelligence, host authorization, hostile Unicode, themes, accessibility, every supported window geometry path, mouse selection, caret-follow scrolling, passive scrollbar updates, and all document-size tiers without a network, database, workspace, credentials, external language server, or arbitrary file access. Inventory entries distinguish interactive, automated-only, and unsupported behavior so labels cannot overstate the live demonstration.

The bounded simulated language service answers completion, hover, signature, symbols, diagnostics, navigation, formatting, cancellation, and recovery requests without retaining source-bearing payloads. Separate controls demonstrate accepted, rejected, and revision-conflicted host saves. A two-editor scenario shares one in-process protocol session while retaining separate URIs, revisions, selections, diagnostics, cancellation, presentation, and host effects; it does not add tabs or an editor manager. Ctrl+Tab switches keyboard focus between the two peers.

For manual acceptance, select any scenario prefixed with QA:. The lower evidence panel explains why the capability matters, the exact interaction, and the expected visible result. Press F5 (or choose Actions → Run current QA check) to invoke that scenario's single primary behavior. The panel reports PASS only after observing the capability-specific presentation, document revision, or bounded host event; selecting or resetting a scenario clears the previous result. Completion and other assistance popups open at the rendered caret, including gutter and scroll offsets, and automatically clamp or flip above it near a viewport edge.

The fixture catalog also covers extension and explicit language selection, a missing-adapter fallback, incomplete and invalid source, LF/CRLF/CR line endings, invisible and hostile Unicode, live theme and degradation transitions, lifecycle decisions, terminal resize, and every document size tier. Redirected execution prints bounded, content-free evidence for the same journeys.