set*Directory Configuration API methods

[valtlai]

Is your feature request related to a problem? Please describe.
There’s no a corresponding method for the dir configuration property.

Describe the solution you'd like
Adding a setDirectories (or something like that) configuration method.

Describe alternatives you've considered
Using the existing property.

Additional context
I’d like to only use methods for consistency.

Also see #1502 for {data,markdown,html}TemplateEngine.

[zachleat]

Completely agree with this and a +1 from me.

[zachleat]

• eleventyConfig.setInputDirectory
• eleventyConfig.setLayoutsDirectory
• eleventyConfig.setIncludesDirectory
• eleventyConfig.setDataDirectory
• eleventyConfig.setOutputDirectory

are shipping with 3.0.0-alpha.6.

These methods will throw an error if you attempt to use them in plugins. These are project-space features only for now!

[zachleat]

Having a few second thoughts about this API, hmm.

Consider this, where the order matters (not ideal):

export default function(eleventyConfig) {
  eleventyConfig.directories.input; // WARN has "./"

  eleventyConfig.addPlugin(eleventyConfig => {
    eleventyConfig.directories.input; // has "./content/"
  });

  eleventyConfig.setInputDirectory("content");

  eleventyConfig.directories.input; // has "./content/"
};

I’m kinda tempted to just move it to be an export level thing in your config file, like this:

export default function(eleventyConfig) {
  eleventyConfig.directories.input; // has "./content/"
};

export const config = {
  dir: {
    input: "content"
  }
}

The above would ensure consistent directory references in your project.

As discussed in #3244, the hope in adding these methods would improve the current situation (and it does improve it) but if we move to a named export we would eliminate these issues entirely:

export default function(eleventyConfig) {
  // IMPROVED by eleventyConfig.setInputDirectory("content");
  // But the API method still needs to be called first (order matters)

  eleventyConfig.directories.input; // WARN has "./"

  eleventyConfig.addPlugin(eleventyConfig => {
    eleventyConfig.directories.input; // has "./content/"
  });

  return {
    dir: {
      input: "content",
    }
  }
};

[zachleat]

Moved that secondary feature to #3246. Given the feedback about this one we’ll keep it around for 3.0.0-alpha.6

[zachleat]

Temporary preview docs: https://11ty-website-git-v3-11ty.vercel.app/docs/config/#configuration-options