🐛 Fix embed mdast structure for executable content (#1221)

.changeset/unlucky-kangaroos-jog.md

@@ -0,0 +1,6 @@
+---
+'myst-cli': patch
+'mystmd': patch
+---
+
+Fix embed mdast structure for executable content

packages/myst-cli/src/transforms/embed.ts

@@ -64,6 +64,11 @@ function mutateEmbedNode(
   }
 }
 
+function targetsToTarget(targets: GenericNode[]): GenericNode {
+  if (targets.length === 1) return copyNode(targets[0]);
+  return { type: 'block', children: copyNode(targets) };
+}
+
 /**
  * This is the {embed} directive, that embeds nodes from elsewhere in a page.
  */
@@ -120,7 +125,8 @@ export async function embedTransform(
             if (!data) return;
             targetNodes = data.mdast.children;
           }
-          const targetNode = { type: 'block', children: targetNodes };
+          if (!targetNodes?.length) return;
+          const targetNode = targetsToTarget(targetNodes);
           (selectAll('crossReference', targetNode) as CrossReference[]).forEach((targetXRef) => {
             // If target xref already has remoteBaseUrl, it can be unchanged in the embedded context
             if (targetXRef.remoteBaseUrl) return;
@@ -183,7 +189,7 @@ export async function embedTransform(
         fileError(vfile, `Embed target for "${label}" not found`, { node });
         return;
       }
-      const target = { type: 'block', children: copyNode(targetNodes) };
+      const target = targetsToTarget(targetNodes);
       if (!(state as MultiPageReferenceResolver).states) {
         // Single page case - we do not need to update urls/dependencies
         mutateEmbedNode(node, target);

packages/mystmd/tests/exports.yml

@@ -138,3 +138,9 @@ cases:
         content: outputs/site-xrefs-config.json
       - path: site-xrefs/_build/site/myst.xref.json
         content: outputs/site-xrefs-myst.xref.json
+  - title: Notebook embed site build
+    cwd: notebook-fig-embed
+    command: myst build
+    outputs:
+      - path: notebook-fig-embed/_build/site/content/index.json
+        content: notebook-fig-embed/outputs/index.json

packages/mystmd/tests/notebook-fig-embed/_toc.yml

@@ -0,0 +1,21 @@
+# Table of Contents
+#
+# Myst will respect:
+# 1. New pages
+#      - file: relative/path/to/page
+# 2. New sections without an associated page
+#      - title: Folder Title
+#        sections: ...
+# 3. New sections with an associated page
+#      - file: relative/path/to/page
+#        sections: ...
+#
+# Note: Titles defined on pages here are not recognized.
+#
+# This spec is based on the JupyterBook table of contents.
+# Learn more at https://jupyterbook.org/customize/toc.html
+
+format: jb-book
+root: index
+chapters:
+  - file: plot

packages/mystmd/tests/notebook-fig-embed/index.md

@@ -0,0 +1,25 @@
+# Plots In Markdown
+
+## Figure directive - local
+
+```{figure} #my-plot
+
+My Caption
+```
+
+## Embed directive - local
+
+```{embed} #my-plot
+```
+
+## Figure directive - external
+
+```{figure} xref:guide#img:altair-horsepower
+
+My Caption
+```
+
+## Embed directive - external
+
+```{embed} xref:guide#img:altair-horsepower
+```

packages/mystmd/tests/notebook-fig-embed/myst.yml

@@ -0,0 +1,24 @@
+# See docs at: https://mystmd.org/guide/frontmatter
+version: 1
+project:
+  id: 715b4b54-6366-422c-af6a-a96359815eaf
+  # title:
+  # description:
+  keywords: []
+  authors: []
+  github: https://github.com/executablebooks/mystjs
+  # bibliography: []
+  thebe: true
+  references:
+    guide: https://mystmd.org/guide
+site:
+  template: book-theme
+  # title:
+  # options:
+  #   favicon: favicon.ico
+  #   logo: site_logo.png
+  nav: []
+  actions:
+    - title: Learn More
+      url: https://mystmd.org/guide
+  domains: []