Excluding `default` from conditions

[brettz9]

Hi,

Great to find such a library, thank you.

I was wondering whether you might add an option such as noDefault to remove checking for default in exports.

https://github.com/lukeed/resolve.exports/blob/master/src/utils.ts#L16

I'm only interested in types or typings.

Thanks!

[regseb]

A proposal with option.noDefault:

Type: boolean Default: false

When truthy, the "default" field is removed from the list of allowed/known conditions.

resolve.exports(pkg, '.', { noDefault: true });
//=> Conditions: ["import", "node"]

resolve.exports(pkg, '.', {
  noDefault: true,
  unsafe: true,
  conditions: ['types'],
});
//=> Conditions: ["types"]

export function conditions(options: t.Options): Set<t.Condition> {
  let out = new Set(options.conditions || []);
  options.noDefault || out.add('default');
  options.unsafe || out.add(options.require ? 'require' : 'import');
  options.unsafe || out.add(options.browser ? 'browser' : 'node');
  return out;
}

---

An other proposal with option.types:

Type: boolean Default: false

When truthy, the "types" field is set to the list of allowed/known conditions.

resolve.exports(pkg, '.', { types: true });
//=> Conditions: ["types"]

resolve.exports(pkg, '.', {
  types: true,
  conditions: ['typings'],
});
//=> Conditions: ["types", "typings"]

export function conditions(options: t.Options): Set<t.Condition> {
  let out = new Set(options.conditions || []);
  if (options.unsafe) {
    out.add('default');
  } else if (options.types) {
    out.add('types');
  } else {
    out.add('default');
    out.add(options.require ? 'require' : 'import');
    out.add(options.browser ? 'browser' : 'node');
  }
  return out;
}

[brettz9]

The first option sounds the most reusable (in case there were any other use cases for dropping default) though either should work for us.

[ljharb]

Why not simply an array of the conditions you want to check? Then it's not specific to "default", or to types.

[brettz9]

Why not simply an array of the conditions you want to check? Then it's not specific to "default", or to types.

That's what conditions already is, but because the existing behavior is to also add default, therein lies the problem. If you're suggesting changing it to avoid the auto-adding of default, then of course, that'd be a breaking change.

[ljharb]

ahhhh, gotcha. then yeah i'd go with noDefault, and then in the next semver-major, remove that option and also the auto-adding behavior.

[brettz9]

that'd work for me too, though I do see an argument for having default preferred by default.

[regseb]

A third proposal with negative conditions:

If you want to undo one of default conditions, you can use the ! prefix, for example: ['!node'].

resolve.exports(pkg, '.');
//=> Conditions: ["default", "import", "node"]

resolve.exports(pkg, '.', { conditions: ['!import'] });
//=> Conditions: ["default", "node"]

resolve.exports(pkg, '.', { conditions: ['!node', 'deno'] });
//=> Conditions: ["default", "import", "deno"]

resolve.exports(pkg, '.', { conditions: ['!default', '!import', '!node', 'types'] });
//=> Conditions: ["types"]

resolve.exports(pkg, '.', { conditions: ['!import', 'require'] }); // Same as { require: true }.
//=> Conditions: ["default", "require", "node"]

resolve.exports(pkg, '.', { conditions: ['!node', 'browser'] }); // Same as { browser: true }.
//=> Conditions: ["default", "import", "browser"]

resolve.exports(pkg, '.', { conditions: ['!import', '!node'] }); // Same as { unsafe: true }.
//=> Conditions: ["default"]

export function conditions(options: t.Options): Set<t.Condition> {
  let out = new Set(['default']);
  options.unsafe || out.add(options.require ? 'require' : 'import');
  options.unsafe || out.add(options.browser ? 'browser' : 'node');
  for (const condition of options.conditions || []) {
    if (condition.startsWith('!')) {
      out.delete(condition.slice(1));
    } else {
      out.add(condition);
    }
  }
  return out;
}

If you want to remove options.require, options.browser and options.unsafe:

export function conditions(options: t.Options): Set<t.Condition> {
  let out = new Set(['default', 'import', 'node']);
  for (const condition of options.conditions || []) {
    if (condition.startsWith('!')) {
      out.delete(condition.slice(1));
    } else {
      out.add(condition);
    }
  }
  return out;
}

[brettz9]

I'm fine myself with the latter approach added to #31 . If that's ok, can it be reviewed?