Cannot use JavaScript view from CLI when project has "type": "module"

[eobrain]

If the package.json for a project has enabled ES6 modules by including

  "type": "module",

then it is not possible to use a JavaScript view.

If you try to create a view with a .js extension then you get an error such as the following:

(node:14179) Warning: require() of ES modules is not supported.
require() of /home/eobrain/src/mergi/template/index_view.js from /home/eobrain/src/mergi/node_modules/mustache/bin/mustache is an ES module file as it is a .js file whose nearest parent package.json contains "type": "module" which defines all .js files in that package scope as ES modules.
Instead rename index_view.js to end in .cjs, change the requiring code to use import(), or remove "type": "module" from /home/eobrain/src/mergi/package.json.
internal/modules/cjs/loader.js:1163
      throw new ERR_REQUIRE_ESM(filename);

If you try to solve the problem by renaming the view to have a .cjs suffix you get an error such as the following

Shooot, could not parse view as JSON.
Tips: functions are not valid JSON and keys / values must be surround with double quotes.

SyntaxError: Unexpected token m in JSON at position 0

because it is not recognized as being JavaScript and it is being parsed as JSON.

[phillipj]

Hi @eobrain,

thanks for taking the time to write such a great bug report, much appreciated!