nvim-exec for javascript/typescript

Sometimes you need fast feedback on the code you are writing. This plugin allows you to execute code from your current buffer. It displays the output as a comment in the same buffer. Currently only javascript and typescript are supported.

You can execute any code within a comment block. The output will be displayed as a comment in the next line(s).

Example: Suppose you have the following fibonacci function in your buffer (btw, this is a terrible way to calculate fibonacci numbers). If you place the cursor in the comment block and execute :ExecCode, you will see the output in the next line(s).

// fibs(10)
// [
//   1,  1,  2,  3,  5,
//   8, 13, 21, 34, 55
// ]
// 
const fibs = (n) => {
  const go = (n) => {
    if (n < 2) return 1;
    return go(n - 1) + go(n - 2);
  }

  return Array.from({ length: n }).reduce((acc, _, i) => [...acc, go(i)], []);
}

The plugin configures a timeout for the code execution. If the code takes longer than the timeout, the execution will be stopped. The default timeout is 10 seconds.

// fibs(100)
// Job timed out
//
const fibs = (n) => {
  const go = (n) => {
    if (n < 2) return 1;
    return go(n - 1) + go(n - 2);
  }

  return Array.from({ length: n }).reduce((acc, _, i) => [...acc, go(i)], []);
}

Of course you know a better way of calculating fibonacci numbers using memoization. You can use the following code to calculate the first 100 fibonacci numbers. If you place the cursor in the comment block and execute :ExecCode, you will see the output in the next line(s).

// fibs(100)
// [
//                       1,                     1,                     2,
//                       3,                     5,                     8,
//                      13,                    21,                    34,
//                      55,                    89,                   144,
//                     233,                   377,                   610,
//                     987,                  1597,                  2584,
//                    4181,                  6765,                 10946,
//                   17711,                 28657,                 46368,
//                   75025,                121393,                196418,
//                  317811,                514229,                832040,
//                 1346269,               2178309,               3524578,
//                 5702887,               9227465,              14930352,
//                24157817,              39088169,              63245986,
//               102334155,             165580141,             267914296,
//               433494437,             701408733,            1134903170,
//              1836311903,            2971215073,            4807526976,
//              7778742049,           12586269025,           20365011074,
//             32951280099,           53316291173,           86267571272,
//            139583862445,          225851433717,          365435296162,
//            591286729879,          956722026041,         1548008755920,
//           2504730781961,         4052739537881,         6557470319842,
//          10610209857723,        17167680177565,        27777890035288,
//          44945570212853,        72723460248141,       117669030460994,
//         190392490709135,       308061521170129,       498454011879264,
//         806515533049393,      1304969544928657,      2111485077978050,
//        3416454622906707,      5527939700884757,      8944394323791464,
//       14472334024676220,     23416728348467684,     37889062373143900,
//       61305790721611580,     99194853094755490,    160500643816367070,
//      259695496911122560,    420196140727489660,    679891637638612200,
//     1100087778366101900,   1779979416004714000,   2880067194370816000,
//     4660046610375530000,   7540113804746346000,  12200160415121877000,
//    19740274219868226000,  31940434634990100000,  51680708854858330000,
//    83621143489848430000, 135301852344706760000, 218922995834555200000,
//   354224848179262000000
// ]
// 
const fibs = (n) => {
  const memo = new Map();
  const go = (n) => {
    if (n < 2) return 1;
    if (memo.has(n)) return memo.get(n);
    const result = go(n - 1) + go(n - 2);
    memo.set(n, result);
    return result;
  }

  return Array.from({ length: n }).reduce((acc, _, i) => [...acc, go(i)], []);
}

Quickstart

Requirements

• Neovim 0.9.5 or later
• Node.js installation
• Nvim-treesitter with parser installation. This plugin uses the treesitter parser to identify the language of the code you want to execute. You can install the parser for the language you are using by running :TSInstall <language> in neovim.

Requirements for Typescript

• Typescript installation
• ts-node

Installation

• Example configuration for lazy:

return {
    "tbsklg/nvim-exec",
    branch = "main",
    dependencies = {
      'nvim-treesitter/nvim-treesitter',
    },
    config = function()
        local nvim_exec = require("nvim-exec").setup({
            timeout = 10000,
            output_mode = "window",
        })
    
        vim.keymap.set({ "n", "v" }, "<leader>r", function()
            nvim_exec.run()
        end, { desc = "Execute code" })
    end,
    ft = "javascript",
}

Default configuration

{
    timeout = 10000, -- Timeout in milliseconds for code execution
    output_mode = "window", -- "comment" || "window"
}

Development

Run linting

make lint

Run formatting

make fmt

Run tests

make test