Integrate CodeMirror command registry and keymap (#2)

Author: bajrangCoder

src/codemirror/baseExtensions.js

@@ -0,0 +1,44 @@
+import { closeBrackets } from "@codemirror/autocomplete";
+import { defaultKeymap, history, historyKeymap } from "@codemirror/commands";
+import {
+	bracketMatching,
+	defaultHighlightStyle,
+	foldGutter,
+	indentOnInput,
+	syntaxHighlighting,
+} from "@codemirror/language";
+import { highlightSelectionMatches } from "@codemirror/search";
+import { EditorState } from "@codemirror/state";
+import {
+	crosshairCursor,
+	drawSelection,
+	dropCursor,
+	highlightActiveLine,
+	highlightSpecialChars,
+	keymap,
+	rectangularSelection,
+} from "@codemirror/view";
+
+/**
+ * Base extensions roughly matching the useful parts of CodeMirror's basicSetup
+ * @returns {import("@codemirror/state").Extension[]}
+ */
+export default function createBaseExtensions() {
+	return [
+		highlightSpecialChars(),
+		history(),
+		drawSelection(),
+		dropCursor(),
+		EditorState.allowMultipleSelections.of(true),
+		indentOnInput(),
+		syntaxHighlighting(defaultHighlightStyle, { fallback: true }),
+		bracketMatching(),
+		closeBrackets(),
+		rectangularSelection(),
+		crosshairCursor(),
+		highlightActiveLine(),
+		highlightSelectionMatches(),
+		foldGutter(),
+		keymap.of([...defaultKeymap, ...historyKeymap]),
+	];
+}