CodeMirror: indent with tab or spaces

gistfile1.js

    editor.addKeyMap({
        "Tab": function (cm) {
            if (cm.somethingSelected()) {
                var sel = editor.getSelection("\n");
                // Indent only if there are multiple lines selected, or if the selection spans a full line
                if (sel.length > 0 && (sel.indexOf("\n") > -1 || sel.length === cm.getLine(cm.getCursor().line).length)) {
                    cm.indentSelection("add");
                    return;
                }
            }

            if (cm.options.indentWithTabs)
                cm.execCommand("insertTab");
            else
                cm.execCommand("insertSoftTab");
        },
        "Shift-Tab": function (cm) {
            cm.indentSelection("subtract");
        }
    });

@cnlohr this is from 10 years ago - the API might have changed

It looks like you have to make a new extensions, based on the baseextensions now, like this:

const baseExtensions = {
	lineNumbers: lineNumbers(),
	highlightActiveLineGutter: highlightActiveLineGutter(),
	highlightSpecialChars: highlightSpecialChars(),
	history: history(),
	foldGutter: foldGutter(),
	drawSelection: drawSelection(),
	dropCursor: dropCursor(),
	allowMultipleSelections: EditorState.allowMultipleSelections.of(true),
	indentOnInput: indentOnInput(),
	syntaxHighlighting: syntaxHighlighting(defaultHighlightStyle, {
		fallback: true,
	}),
	//bracketMatching: bracketMatching(),
	//closeBrackets: closeBrackets(),
	autocompletion: autocompletion(),
	rectangularSelection: rectangularSelection(),
	crosshairCursor: crosshairCursor(),
	highlightActiveLine: highlightActiveLine(),
	highlightSelectionMatches: highlightSelectionMatches(),
	keymap: keymap.of([
		indentWithTab,    <<<
		...defaultKeymap,
		...searchKeymap,
		...historyKeymap,
		...foldKeymap,
		...completionKeymap,
		...lintKeymap,
		//...closeBracketsKeymap,
	]),
	indentUnit : indentUnit.of("\t"),   <<<
};

It can be toggled with:

	const filteredExtensions = filteredBase(showLineNos ? [] : ["indentUnit"]);
	view.dispatch({
		effects: StateEffect.reconfigure.of([...filteredExtensions, cpp()]),
	});