rework valueless text adapter to be backwards-compatible with edge-cases (#1737)

When implementing the remark rehype rework, which was supposed to be backwards-compatible, incorrect mdast was produced by the remarkValuelessTextAdapter in some edge-cases. This caused markdown generated by other plugins, such as the issue-tracker-plugin, to be faulty (e.g. Und die #10 ist *so* toll caused visual artifacts). This PR solves the issue by inlining the children of the empty text node instead of wrapping them in a paragraph. This is also more consistent with the previous output, as can be observed when pairing SCM-Manager <= 2.15.0 with the issue-tracker-plugin and using the aforementioned snippet.

gradle/changelog/remark-text-adapter.yaml

@@ -0,0 +1,2 @@
+- type: fixed
+  description: Make MarkdownView backwards-compatible with edge-cases ([#1737](https://github.com/scm-manager/scm-manager/pull/1737))

scm-ui/ui-components/src/__resources__/markdown-commit-link.md.ts

@@ -24,9 +24,9 @@
 export default `# Commit Links in Markdown
 namespace/name@1a5s4w8a
 
-Please check for this commit: namespace/name@1a5s4w8a
+Please check for this commit: namespace/name@1a5s4w8a it *works*
 
-hitchhiker/heart-of-gold@c7237cb60689046990dc9dc2a388a517adb3e2b2
+**really** also check *this* commit: hitchhiker/heart-of-gold@c7237cb60689046990dc9dc2a388a517adb3e2b2
 
 hitchhiker/heart-of-gold@c7237cb
 

scm-ui/ui-components/src/__snapshots__/storyshots.test.ts.snap

@@ -53591,7 +53591,6 @@ exports[`Storyshots MarkdownView Commit Links 1`] = `
       </h1>
       
 
-      <p />
       <p>
         <a
           href="/repo/namespace/name/code/changeset/1a5s4w8a"
@@ -53600,10 +53599,8 @@ exports[`Storyshots MarkdownView Commit Links 1`] = `
           namespace/name@1a5s4w8a
         </a>
       </p>
-      <p />
       
 
-      <p />
       <p>
         Please check for this commit: 
         <a
@@ -53612,12 +53609,22 @@ exports[`Storyshots MarkdownView Commit Links 1`] = `
         >
           namespace/name@1a5s4w8a
         </a>
+         it 
+        <em>
+          works
+        </em>
       </p>
-      <p />
       
 
-      <p />
       <p>
+        <strong>
+          really
+        </strong>
+         also check 
+        <em>
+          this
+        </em>
+         commit: 
         <a
           href="/repo/hitchhiker/heart-of-gold/code/changeset/c7237cb60689046990dc9dc2a388a517adb3e2b2"
           title="changeset.shortlink.title"
@@ -53625,10 +53632,8 @@ exports[`Storyshots MarkdownView Commit Links 1`] = `
           hitchhiker/heart-of-gold@c7237cb60689046990dc9dc2a388a517adb3e2b2
         </a>
       </p>
-      <p />
       
 
-      <p />
       <p>
         <a
           href="/repo/hitchhiker/heart-of-gold/code/changeset/c7237cb"
@@ -53637,10 +53642,8 @@ exports[`Storyshots MarkdownView Commit Links 1`] = `
           hitchhiker/heart-of-gold@c7237cb
         </a>
       </p>
-      <p />
       
 
-      <p />
       <p>
         <a
           href="/repo/hitchhiker/heart-of-gold/code/changeset/42"
@@ -53649,7 +53652,6 @@ exports[`Storyshots MarkdownView Commit Links 1`] = `
           hitchhiker/heart-of-gold@42
         </a>
       </p>
-      <p />
       
 
       <p>
@@ -53663,7 +53665,6 @@ exports[`Storyshots MarkdownView Commit Links 1`] = `
       </p>
       
 
-      <p />
       <p>
         Prefix 
         <a
@@ -53681,7 +53682,6 @@ exports[`Storyshots MarkdownView Commit Links 1`] = `
         </a>
          suffix
       </p>
-      <p />
     </div>
   </div>
 </div>

scm-ui/ui-components/src/markdown/remarkValuelessTextAdapter.ts

@@ -28,13 +28,37 @@ import { Node, Parent } from "unist";
 /**
  * Some existing remark plugins (e.g. changesetShortLinkParser or the plugin for issue tracker links) create
  * text nodes without values but with children. This does not get parsed properly by remark2rehype.
- * This remark-plugin transforms all of these invalid text nodes to valid paragraphs.
+ * This remark-plugin takes the children of these invalid text nodes and inserts them into the node's parent
+ * in place of the text node.
+ *
+ * @example
+ * ```
+ * # This ->
+ *
+ * validNode
+ * invalidNode
+ *  child1
+ *  child2
+ *  child3
+ * validNode
+ *
+ * # Becomes ->
+ *
+ * validNode
+ * child1
+ * child2
+ * child3
+ * validNode
+ * ```
  */
 export const createTransformer = (): AstPlugin => {
   return ({ visit }) => {
     visit("text", (node: Node, index: number, parent?: Parent) => {
       if (node.value === undefined && Array.isArray(node.children) && node.children.length > 0) {
-        node.type = "paragraph";
+        const children = node.children;
+        const preChildren = parent?.children.slice(0, index) || [];
+        const postChildren = parent?.children.slice(index + 1) || [];
+        parent!.children = [...preChildren, ...children, ...postChildren];
       }
     });
   };