Remove unnecessary markup from core templates, a.k.a. divitis

Thanks @davidhernandez, this needs a reroll now.

rerolling a patch.

Rerolled.

Rerolled #3.

Thanks for the rerolls folks. Before any further work, this one thing from the reroll needs to be fixed:

+++ b/core/modules/system/templates/maintenance-page.html.twig
@@ -11,57 +11,52 @@
+{{ page.highlighted }}
...
-    {{ page.highlighted }}
+<main role="main">
+  {% if title %}
+    <h1>{{ title }}</h1>
+  {% endif %}
 
-    {{ page.content }}
-  </main>
+  {{ page.messages }}

It's hard to tell all this does from the diff because of the indentation changes, but it adds back the now-removed messages region #2470807: Rename the default "Messages" region for all themes to "Highlighted", and moves the highlighted region back up. Only the indentation of this hunk should be changing. Screenshot from my visual diff tool is the best way I can think to show this:

1. +++ b/core/modules/link/templates/link-formatter-link-separate.html.twig
   @@ -15,10 +15,8 @@
   +  {% if title %}
   +    {{ title }}
   +  {% endif %}
   

   I'm thrilled to say that this if can now be removed :)

2. +++ b/core/modules/system/templates/block--system-branding-block.html.twig
   @@ -22,11 +22,9 @@
      {% if site_slogan %}
   -    <div>{{ site_slogan }}</div>
   +    {{ site_slogan }}
      {% endif %}
   

   And this one too.

3. +++ b/core/modules/system/templates/datetime-wrapper.html.twig
   @@ -25,5 +25,5 @@
    {% if description %}
   -  <div>{{ description }}</div>
   +  {{ description }}
    {% endif %}
   

   Yup.

4. +++ b/core/modules/system/templates/details.html.twig
   @@ -19,15 +19,16 @@
   +  {%- if description -%}
   +    {{ description }}
   +  {%- endif -%}
   +
   +  {%- if children -%}
   +    {{ children }}
   +  {%- endif -%}
   +
   +  {%- if value -%}
   +    {{ value }}
   +  {%- endif -%}
   

   Bye bye.

Fixed the reroll. Hope it is correct now. :)

The changes look great, thanks @sumitmadan!

+++ b/core/modules/system/templates/details.html.twig
@@ -19,15 +19,10 @@
+  {{ description }}
+
+  {{ children }}
+
+  {{ value }}

I think we can remove the blank lines in between each variable here. We can still keep a blank line between the endif above and the first variable output (description).

Done, Thanks. :)

Always interdiff, please :)

(except when rerolling a patch that doesn't apply)

Sorry. I'll keep this in mind next time. Thanks. :)

Working on manually testing this.

+++ b/core/modules/image/templates/image-widget.html.twig
@@ -14,12 +14,9 @@
   {% if data.preview %}
-    <div>
-      {{ data.preview }}
-    </div>
+    {{ data.preview }}
   {% endif %}

This if can be removed as well.

Testing is going well, finding some (unrelated) core bugs in the process.

Thanks all!

This all checks out, there are only two small visual changes (which are link-formatter-link-separate.html.twig and block--system-branding-block.html.twig), the former @LewisNyman pointed out in #2483319-17: [META] Remove unnecessary markup from core templates, a.k.a. divitis and I think they are both perfectly acceptable for Stark. I'm uploading the full set of before/after screenshots I took (we need a bulk upload!) but only embedding in the issue summary cropped versions of the ones that change visually (because otherwise it's 4.5+ MB of screenshots even after putting everything through ImageOptim [it doesn't help that half of them are 2x resolution either]!).

I should probably set up that tool that @LewisNyman is using…

To test node-edit-form.html.twig (normally only used by Seven), I added the following code to node.module:

function node_form_node_form_alter(&$form, FormStateInterface $form_state) {
  $form['#theme'] = array('node_edit_form');
}

I also had to hack some things to test the image-widget.html.twig template, I'll create a separate bug issue for that as soon as I can, it's related to the form process callbacks, the #theme gets clobbered.

Right it does help if the patch is visible in the IS :)

Thanks @Cottser for an awesome review. Committed f3e2e68 and pushed to 8.0.x. Thanks!

Thanks for adding the beta evaluation to issue summary.

Created the issue as promised (better late than never) for this bug from #17:

I also had to hack some things to test the image-widget.html.twig template, I'll create a separate bug issue for that as soon as I can, it's related to the form process callbacks, the #theme gets clobbered.

#2511036: image-widget.html.twig never gets used (image_widget gets overridden by FieldWidget::process)