QuickPick Multi-Select Custom Input

quickpick-input.ts

export async function quickPickTag(
    tags: string[],
    canSelectMany: boolean = false,
    acceptInput: boolean = true): Promise<string[]> {
    let options = tags.map(tag => ({ label: tag }));

    return new Promise((resolve, _) => {
        let quickPick = vscode.window.createQuickPick();
        let placeholder = "Select a tag.";

        if (acceptInput) {
            placeholder = "Select/Insert a tag.";
        }
        
        quickPick.placeholder = placeholder;
        quickPick.canSelectMany = canSelectMany;
        quickPick.items = options;
        let selectedItems = [];

        if (canSelectMany) {
            quickPick.onDidChangeSelection((selected) => {
                selectedItems = selected;
            });
        }

        quickPick.onDidAccept(_ => {
            if (quickPick.value.trim().length > 0 || selectedItems.length > 0 || quickPick.activeItems.length > 0) {
                if (canSelectMany) {
                    resolve(selectedItems.map((item) => item.label));
                } else {
                    resolve(quickPick.activeItems.map((item) => item.label));
                }
                quickPick.hide();
            }
        });

        if (acceptInput) {
            quickPick.onDidChangeValue(_ => {
                if (quickPick.value.trim().length === 0) {
                    quickPick.value = '';
                    quickPick.items = options;
                } else {
                    // include currently typed option
                    if (tags.indexOf(quickPick.value.trim()) === -1) {
                        quickPick.items = [{ label: quickPick.value.trim() }, ...options];
                    }
                }
            });
        }

        quickPick.onDidHide(_ => quickPick.dispose());
        quickPick.show();
    });
}

One further modification - quickPick.items = [{ label: quickPick.value }, ...options]; should change quickPick.value to quickPick.value.trim() or you end up with some entertaining things in the list!

Thanks, @bfitzpat. I'll update it.