Convert ADF codeblocks to fenced codeblocks

with proper language attribution

changelogs/unreleased/223097-support-fenced-code-blocks-in-atlassian-document-format-converter.yml

+---
+title: Support fenced code blocks in Atlassian Document Format converter
+merge_request: 35065
+author:
+type: fixed

lib/kramdown/converter/commonmark.rb

@@ -12,6 +12,46 @@ module Kramdown
     # Note: this is only an initial implementation.  Currently don't
     # strip out IALs or other specific kramdown syntax.
     class Commonmark < ::Kramdown::Converter::Kramdown
+      # replaces the ^ used in kramdown.  This forces the current
+      # block to end, so that a different list or codeblock can be
+      # started. https://kramdown.gettalong.org/syntax.html#eob-marker
+      END_OF_BLOCK = '<!-- -->'
+
+      def convert(el, opts = { indent: 0 })
+        res = super
+
+        if [:ul, :dl, :ol, :codeblock].include?(el.type) && opts[:next] &&
+          ([el.type, :codeblock].include?(opts[:next].type) ||
+            (opts[:next].type == :blank && opts[:nnext] &&
+              [el.type, :codeblock].include?(opts[:nnext].type)))
+          # replace the end of block character
+          res.sub!(/\^\n\n\z/m, "#{END_OF_BLOCK}\n\n")
+        end
+
+        res
+      end
+
+      def convert_codeblock(el, _opts)
+        # Although tildes are supported in CommonMark, backticks are more common
+        "```#{el.options[:lang]}\n" +
+          el.value.split(/\n/).map {|l| l.empty? ? "" : "#{l}" }.join("\n") +
+          "\n```\n\n"
+      end
+
+      def convert_li(el, opts)
+        res = super
+
+        if el.children.first && el.children.first.type == :p && !el.children.first.options[:transparent]
+          if el.children.size == 1 && @stack.last.children.last == el &&
+            (@stack.last.children.any? {|c| c.children.first.type != :p } || @stack.last.children.size == 1)
+            # replace the end of block character
+            res.sub!(/\^\n\z/m, "#{END_OF_BLOCK}\n")
+          end
+        end
+
+        res
+      end
+
       def convert_table(el, opts)
         return super unless @options[:html_tables]
 

spec/fixtures/lib/kramdown/atlassian_document_format/code_block.json

@@ -14,6 +14,18 @@
         }
       ]
     },
+    {
+      "type": "codeBlock",
+      "attrs": {
+        "language": "css"
+      },
+      "content": [
+        {
+          "type": "text",
+          "text": ".overflow { overflow: hidden; }"
+        }
+      ]
+    },
     {
       "type": "bulletList",
       "content": [
@@ -37,6 +49,37 @@
                   "text": "public DemoClass()\n{\n  // assign default value\n  x = 0;\n}"
                 }
               ]
+            },
+            {
+              "type": "orderedList",
+              "content": [
+                {
+                  "type": "listItem",
+                  "content": [
+                    {
+                      "type": "paragraph",
+                      "content": [
+                        {
+                          "type": "text",
+                          "text": "Number list Item 1"
+                        }
+                      ]
+                    },
+                    {
+                      "type": "codeBlock",
+                      "attrs": {
+                        "language": "ruby"
+                      },
+                      "content": [
+                        {
+                          "type": "text",
+                          "text": "def test\n  # assign default value\n  x = 0\nend"
+                        }
+                      ]
+                    }
+                  ]
+                }
+              ]
             }
           ]
         }

spec/fixtures/lib/kramdown/atlassian_document_format/code_block.md

-    export function makeIssue({ parentIssue, project, users }) {
+```javascript
+export function makeIssue({ parentIssue, project, users }) {
 
   const issueType = pickRandom(project.issueTypes)
 
   console.log(data)
 
   return data
-    }
+}
+```
+
+<!-- -->
+
+```css
+.overflow { overflow: hidden; }
+```
+
 
 * Item 1
   
+  ```java
   public DemoClass()
   {
     // assign default value
     x = 0;
   }
+  ```
+  
+  
+  1.  Number list Item 1
+      
+      ```ruby
+      def test
+        # assign default value
+        x = 0
+      end
+      ```
 

spec/fixtures/lib/kramdown/atlassian_document_format/complex_document.md

@@ -165,7 +165,8 @@ Col 3 Row 3
 
 <del>Strikethrough</del>
 
-    export function makeIssue({ parentIssue, project, users }) {
+```javascript
+export function makeIssue({ parentIssue, project, users }) {
    
   const issueType = pickRandom(project.issueTypes)
 
@@ -195,7 +196,9 @@ Col 3 Row 3
   console.log(data)
 
   return data
-    }
+}
+```
+
 
 ![jira-10050-field-description](adf-media://79411c6b-50e0-477f-b4ed-ac3a5887750c)
 

spec/fixtures/lib/kramdown/atlassian_document_format/ordered_list.json

@@ -146,6 +146,25 @@
           ]
         }
       ]
+    },
+    {
+      "type": "orderedList",
+      "content": [
+        {
+          "type": "listItem",
+          "content": [
+            {
+              "type": "paragraph",
+              "content": [
+                {
+                  "type": "text",
+                  "text": "Another list"
+                }
+              ]
+            }
+          ]
+        }
+      ]
     }
   ]
 }

spec/fixtures/lib/kramdown/atlassian_document_format/ordered_list.md

@@ -17,4 +17,9 @@
 9.  Number list item 9
 
 10. Number list item 10
+<!-- -->
+
+1.  Another list
+
+<!-- -->