How to apply tsconfig.json to the Emacs org-babel?

Question

I am using Emacs with org-babel mode to insert the TypeScript code example in my org-mode document. The elisp I have added in .emacs.d/init.el is as follows:

(eval-after-load "org" '(org-babel-do-load-languages 'org-babel-load-languages '((typescript . t))))
(require 'typescript-mode)
(add-to-list 'auto-mode-alist '("\\.ts\\'" . typescript-mode))
(require 'tide)

Now, I want to make the following code as error:

#+BEGIN_SRC typescript :results output 
let data_1: string = undefined;
let data_2: string = null;
#+END_SRC

I think I can make it by specifying tsconfig.json as:

{
  "compilerOptions": {
    "strictNullChecks": true,
  },
}

But where can I put tsconfig.json?

I modified ~/.emacs.d/elpa/tide-20200327.1218/tsserver/tsconfig.json and restarded Emacs but nothing changed.

I ran tsc from the command line and confirmed tsconfig.json works as expected.

Thank you.

Answer 1

To make the code you've mentioned display an error, you can use the :cmdline parameter. That allows you to pass command line parameters (such as --strictNullChecks) directly to tsc:

#+BEGIN_SRC typescript :cmdline --strictNullChecks :results output
let data_1: string = undefined;
let data_2: string = null;
#+END_SRC

I don't think you can use tsconfig.json to configure this, because to evaluate the code block, emacs first saves the code to a temp file (e.g. /tmp/babel-5NJb2Q/ob-input-Afjtyu) and then runs the tsc on it (see ob-typescript.el). That temp file bears no relation to your tsconfig.json.