5.x: unique content sources for each build environment

[cossssmin]

Because we now use globs for content sources (similar to Tailwind CSS v3), the environment config merging strategy falls short in some cases. For example, consider the following setup:

config.js

export default {
  build: {
    content: ['src/templates/**/*.html'],
  }
}

config.sendgrid.js

export default {
  build: {
    content: ['src/templates/sendgrid/**/*.html'],
  }
}

Normally, when we run maizzle build sendgrid we'd expect it to just build our Sendgrid templates.

However, if src/templates also contains some assets folders, like say images, then because of the config merging the src/images folder will also be considered a templates source.

That would work, as in the folder would just get copied over and the build would succeed.

However, we'd get a build output folder with this structure:

build_sendgrid
|-- sendgrid
|-- images

When in fact we just want this:

build_sendgrid
|-- sendgrid

Solution

To fix this we could try to not merge the build.content keys, effectively overriding the one you have in config.js.

This would be a breaking change if you're relying on the merging strategy when building for production, i.e. you need templates defined in build.content from config.js and are just adding sources to it - in this case you'd need to always define all of your content sources in each config file.

Note: I ran into this a few times while working on real life projects with v5 beta, but I might be biased in the way I use it, so leaving this open for now - input is appreciated 👍

[cossssmin]

Implemented in #1299 / 8d9a65f