Fix blank lines between list items and nested sub-lists being removed in Markdown/MDX (#17857)

Co-authored-by: Tatsunori Uchino <tats.u@live.jp>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: fisker Cheung <lionkay@gmail.com>

changelog_unreleased/markdown/17746.md

@@ -0,0 +1,31 @@
+#### Fix blank lines between list items and nested sub-lists being removed in Markdown/MDX (#17746 by @byplayer)
+
+Prettier was removing blank lines between list items and their nested sub-lists, converting loose lists into tight lists and changing their semantic meaning.
+
+<!-- prettier-ignore -->
+```markdown
+<!-- Input -->
+- a
+
+  - b
+
+- c
+
+
+  - d
+
+<!-- Prettier stable -->
+- a
+  - b
+- c
+  - d
+
+<!-- Prettier main -->
+- a
+
+  - b
+
+- c
+
+  - d
+```

src/language-markdown/print/children.js

@@ -63,7 +63,10 @@ function shouldPrePrintDoubleHardline({ node, previous, parent }, options) {
     isLooseListItem(previous, options) ||
     (node.type === "list" &&
       parent.type === "listItem" &&
-      previous.type === "code")
+      (previous.type === "code" ||
+        // Preserve blank line before nested list within listItem (issue #17746)
+        previous.type === "paragraph") &&
+      previous.position.end.line + 1 < node.position.start.line)
   ) {
     return true;
   }

tests/format/markdown/list/__snapshots__/format.test.js.snap

@@ -1232,6 +1232,7 @@ tabWidth: 0
 =====================================output=====================================
 - [ ] a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
       a a a a a a a a a a a a a a a
+
   - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
     a a a a a a a a a a a a a a
 
@@ -1270,6 +1271,7 @@ tabWidth: 0
 
 1. [ ] a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
        a a a a a a a a a a a a a a a
+
    - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
      a a a a a a a a a a a a a a
 
@@ -1311,6 +1313,7 @@ tabWidth: 0
 
           b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b
           b b b b b b b b b b b b b b b
+
           - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
             a a a a a a a a a a a a a a a
 
@@ -1447,6 +1450,7 @@ tabWidth: 4
 =====================================output=====================================
 - [ ] a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
       a a a a a a a a a a a a a a a
+
     - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
       a a a a a a a a a a a a a a a
 
@@ -1485,6 +1489,7 @@ tabWidth: 4
 
 1. [ ] a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
        a a a a a a a a a a a a a a a
+
     - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
       a a a a a a a a a a a a a a a
 
@@ -1526,6 +1531,7 @@ tabWidth: 4
 
           b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b
           b b b b b b b b b b b b b b b
+
           - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
             a a a a a a a a a a a a a a a
 
@@ -1662,6 +1668,7 @@ tabWidth: 999
 =====================================output=====================================
 - [ ] a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
       a a a a a a a a a a a a a a a
+
      - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
        a a a a a a a a a a a a a a a
 
@@ -1700,6 +1707,7 @@ tabWidth: 999
 
 1. [ ] a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
        a a a a a a a a a a a a a a a
+
       - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
         a a a a a a a a a a a a a a a a
 
@@ -1741,6 +1749,7 @@ tabWidth: 999
 
              b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b
              b b b b b b b b b b b b b b b b
+
              - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
                a a a a a a a a a a a a a a a a
 
@@ -1876,6 +1885,7 @@ proseWrap: "always"
 =====================================output=====================================
 - [ ] a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
       a a a a a a a a a a a a a a a
+
   - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
     a a a a a a a a a a a a a a
 
@@ -1914,6 +1924,7 @@ proseWrap: "always"
 
 1. [ ] a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
        a a a a a a a a a a a a a a a
+
    - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
      a a a a a a a a a a a a a a
 
@@ -1955,6 +1966,7 @@ proseWrap: "always"
 
           b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b
           b b b b b b b b b b b b b b b
+
           - a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
             a a a a a a a a a a a a a a a
 
@@ -2339,6 +2351,7 @@ tabWidth: 0
    2. List
 
 1. Some text, and code block below, with newline after code block
+
    1. Another
    2. List
 
@@ -2397,6 +2410,7 @@ tabWidth: 4
     2. List
 
 1. Some text, and code block below, with newline after code block
+
     1. Another
     2. List
 
@@ -2455,6 +2469,7 @@ tabWidth: 999
       2. List
 
 1. Some text, and code block below, with newline after code block
+
       1. Another
       2. List
 
@@ -2512,6 +2527,7 @@ proseWrap: "always"
    2. List
 
 1. Some text, and code block below, with newline after code block
+
    1. Another
    2. List
 
@@ -2526,6 +2542,505 @@ proseWrap: "always"
 ================================================================================
 `;
 
+exports[`issue-17746.md - {"proseWrap":"always","tabWidth":0} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+tabWidth: 0
+                                                                                | printWidth
+=====================================input======================================
+- a
+
+  - b
+
+- c
+
+
+  - d
+
+=====================================output=====================================
+- a
+
+  - b
+
+- c
+
+  - d
+
+================================================================================
+`;
+
+exports[`issue-17746.md - {"proseWrap":"always","tabWidth":4} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+tabWidth: 4
+                                                                                | printWidth
+=====================================input======================================
+- a
+
+  - b
+
+- c
+
+
+  - d
+
+=====================================output=====================================
+- a
+
+    - b
+
+- c
+
+    - d
+
+================================================================================
+`;
+
+exports[`issue-17746.md - {"proseWrap":"always","tabWidth":999} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+tabWidth: 999
+                                                                                | printWidth
+=====================================input======================================
+- a
+
+  - b
+
+- c
+
+
+  - d
+
+=====================================output=====================================
+- a
+
+     - b
+
+- c
+
+     - d
+
+================================================================================
+`;
+
+exports[`issue-17746.md - {"proseWrap":"always"} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+                                                                                | printWidth
+=====================================input======================================
+- a
+
+  - b
+
+- c
+
+
+  - d
+
+=====================================output=====================================
+- a
+
+  - b
+
+- c
+
+  - d
+
+================================================================================
+`;
+
+exports[`issue-17746-code-before-list.md - {"proseWrap":"always","tabWidth":0} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+tabWidth: 0
+                                                                                | printWidth
+=====================================input======================================
+-     a
+  - b
+- c
+- d
+
+=====================================output=====================================
+-     a
+  - b
+- c
+- d
+
+================================================================================
+`;
+
+exports[`issue-17746-code-before-list.md - {"proseWrap":"always","tabWidth":4} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+tabWidth: 4
+                                                                                | printWidth
+=====================================input======================================
+-     a
+  - b
+- c
+- d
+
+=====================================output=====================================
+-     a
+    - b
+- c
+- d
+
+================================================================================
+`;
+
+exports[`issue-17746-code-before-list.md - {"proseWrap":"always","tabWidth":999} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+tabWidth: 999
+                                                                                | printWidth
+=====================================input======================================
+-     a
+  - b
+- c
+- d
+
+=====================================output=====================================
+-     a
+     - b
+- c
+- d
+
+================================================================================
+`;
+
+exports[`issue-17746-code-before-list.md - {"proseWrap":"always"} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+                                                                                | printWidth
+=====================================input======================================
+-     a
+  - b
+- c
+- d
+
+=====================================output=====================================
+-     a
+  - b
+- c
+- d
+
+================================================================================
+`;
+
+exports[`issue-17746-code-sibling-nested-list.md - {"proseWrap":"always","tabWidth":0} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+tabWidth: 0
+                                                                                | printWidth
+=====================================input======================================
+- a
+  \`\`\`
+  b
+  \`\`\`
+- c
+
+  - d
+
+=====================================output=====================================
+- a
+  \`\`\`
+  b
+  \`\`\`
+- c
+
+  - d
+
+================================================================================
+`;
+
+exports[`issue-17746-code-sibling-nested-list.md - {"proseWrap":"always","tabWidth":4} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+tabWidth: 4
+                                                                                | printWidth
+=====================================input======================================
+- a
+  \`\`\`
+  b
+  \`\`\`
+- c
+
+  - d
+
+=====================================output=====================================
+- a
+    \`\`\`
+    b
+    \`\`\`
+- c
+
+    - d
+
+================================================================================
+`;
+
+exports[`issue-17746-code-sibling-nested-list.md - {"proseWrap":"always","tabWidth":999} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+tabWidth: 999
+                                                                                | printWidth
+=====================================input======================================
+- a
+  \`\`\`
+  b
+  \`\`\`
+- c
+
+  - d
+
+=====================================output=====================================
+- a
+     \`\`\`
+     b
+     \`\`\`
+- c
+
+     - d
+
+================================================================================
+`;
+
+exports[`issue-17746-code-sibling-nested-list.md - {"proseWrap":"always"} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+                                                                                | printWidth
+=====================================input======================================
+- a
+  \`\`\`
+  b
+  \`\`\`
+- c
+
+  - d
+
+=====================================output=====================================
+- a
+  \`\`\`
+  b
+  \`\`\`
+- c
+
+  - d
+
+================================================================================
+`;
+
+exports[`issue-17746-fenced-code-then-nested-list.md - {"proseWrap":"always","tabWidth":0} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+tabWidth: 0
+                                                                                | printWidth
+=====================================input======================================
+- \`\`\`
+  a
+  \`\`\`
+
+  - b
+- c
+
+=====================================output=====================================
+- \`\`\`
+  a
+  \`\`\`
+
+  - b
+
+- c
+
+================================================================================
+`;
+
+exports[`issue-17746-fenced-code-then-nested-list.md - {"proseWrap":"always","tabWidth":4} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+tabWidth: 4
+                                                                                | printWidth
+=====================================input======================================
+- \`\`\`
+  a
+  \`\`\`
+
+  - b
+- c
+
+=====================================output=====================================
+- \`\`\`
+  a
+  \`\`\`
+
+    - b
+
+- c
+
+================================================================================
+`;
+
+exports[`issue-17746-fenced-code-then-nested-list.md - {"proseWrap":"always","tabWidth":999} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+tabWidth: 999
+                                                                                | printWidth
+=====================================input======================================
+- \`\`\`
+  a
+  \`\`\`
+
+  - b
+- c
+
+=====================================output=====================================
+- \`\`\`
+  a
+  \`\`\`
+
+     - b
+
+- c
+
+================================================================================
+`;
+
+exports[`issue-17746-fenced-code-then-nested-list.md - {"proseWrap":"always"} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+                                                                                | printWidth
+=====================================input======================================
+- \`\`\`
+  a
+  \`\`\`
+
+  - b
+- c
+
+=====================================output=====================================
+- \`\`\`
+  a
+  \`\`\`
+
+  - b
+
+- c
+
+================================================================================
+`;
+
+exports[`issue-17746-indented-code-then-nested-list.md - {"proseWrap":"always","tabWidth":0} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+tabWidth: 0
+                                                                                | printWidth
+=====================================input======================================
+-     a
+
+  - b
+
+=====================================output=====================================
+-     a
+
+  - b
+
+================================================================================
+`;
+
+exports[`issue-17746-indented-code-then-nested-list.md - {"proseWrap":"always","tabWidth":4} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+tabWidth: 4
+                                                                                | printWidth
+=====================================input======================================
+-     a
+
+  - b
+
+=====================================output=====================================
+-     a
+
+    - b
+
+================================================================================
+`;
+
+exports[`issue-17746-indented-code-then-nested-list.md - {"proseWrap":"always","tabWidth":999} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+tabWidth: 999
+                                                                                | printWidth
+=====================================input======================================
+-     a
+
+  - b
+
+=====================================output=====================================
+-     a
+
+     - b
+
+================================================================================
+`;
+
+exports[`issue-17746-indented-code-then-nested-list.md - {"proseWrap":"always"} format 1`] = `
+====================================options=====================================
+parsers: ["markdown"]
+printWidth: 80
+proseWrap: "always"
+                                                                                | printWidth
+=====================================input======================================
+-     a
+
+  - b
+
+=====================================output=====================================
+-     a
+
+  - b
+
+================================================================================
+`;
+
 exports[`long-paragraph.md - {"proseWrap":"always","tabWidth":0} format 1`] = `
 ====================================options=====================================
 parsers: ["markdown"]
@@ -2615,12 +3130,15 @@ tabWidth: 0
 
 =====================================output=====================================
 - 123
+
   - abc
 
 - 456
+
   - def
 
 - 789
+
   - ghi
 
 ================================================================================
@@ -2648,12 +3166,15 @@ tabWidth: 4
 
 =====================================output=====================================
 - 123
+
     - abc
 
 - 456
+
     - def
 
 - 789
+
     - ghi
 
 ================================================================================
@@ -2681,12 +3202,15 @@ tabWidth: 999
 
 =====================================output=====================================
 - 123
+
      - abc
 
 - 456
+
      - def
 
 - 789
+
      - ghi
 
 ================================================================================
@@ -2713,12 +3237,15 @@ proseWrap: "always"
 
 =====================================output=====================================
 - 123
+
   - abc
 
 - 456
+
   - def
 
 - 789
+
   - ghi
 
 ================================================================================
@@ -2897,6 +3424,7 @@ tabWidth: 0
 =====================================output=====================================
 - parent list item parent list item parent list item parent list item parent
   list item parent list item
+
   - child list item child list item child list item child list item child list
     item child list item
 
@@ -2905,6 +3433,7 @@ tabWidth: 0
 
 - [x] parent task list item parent task list item parent task list item parent
       task list item
+
   - [x] child task list item child task list item child task list item child
         task list item
 
@@ -2937,6 +3466,7 @@ tabWidth: 4
 =====================================output=====================================
 - parent list item parent list item parent list item parent list item parent
   list item parent list item
+
     - child list item child list item child list item child list item child list
       item child list item
 
@@ -2945,6 +3475,7 @@ tabWidth: 4
 
 - [x] parent task list item parent task list item parent task list item parent
       task list item
+
     - [x] child task list item child task list item child task list item child
           task list item
 
@@ -2977,6 +3508,7 @@ tabWidth: 999
 =====================================output=====================================
 - parent list item parent list item parent list item parent list item parent
   list item parent list item
+
      - child list item child list item child list item child list item child
        list item child list item
 
@@ -2985,6 +3517,7 @@ tabWidth: 999
 
 - [x] parent task list item parent task list item parent task list item parent
       task list item
+
      - [x] child task list item child task list item child task list item child
            task list item
 
@@ -3016,6 +3549,7 @@ proseWrap: "always"
 =====================================output=====================================
 - parent list item parent list item parent list item parent list item parent
   list item parent list item
+
   - child list item child list item child list item child list item child list
     item child list item
 
@@ -3024,6 +3558,7 @@ proseWrap: "always"
 
 - [x] parent task list item parent task list item parent task list item parent
       task list item
+
   - [x] child task list item child task list item child task list item child
         task list item
 
@@ -4390,6 +4925,7 @@ tabWidth: 0
   [title](link)
 
 - Text
+
   - foo
   - foo
   - bar
@@ -4449,6 +4985,7 @@ tabWidth: 4
     [title](link)
 
 - Text
+
     - foo
     - foo
     - bar
@@ -4508,6 +5045,7 @@ tabWidth: 999
      [title](link)
 
 - Text
+
      - foo
      - foo
      - bar
@@ -4566,6 +5104,7 @@ proseWrap: "always"
   [title](link)
 
 - Text
+
   - foo
   - foo
   - bar

tests/format/markdown/list/issue-17746-code-before-list.md

@@ -0,0 +1,4 @@
+-     a
+  - b
+- c
+- d

tests/format/markdown/list/issue-17746-code-sibling-nested-list.md

@@ -0,0 +1,7 @@
+- a
+  ```
+  b
+  ```
+- c
+
+  - d

tests/format/markdown/list/issue-17746-fenced-code-then-nested-list.md

@@ -0,0 +1,6 @@
+- ```
+  a
+  ```
+
+  - b
+- c

tests/format/markdown/list/issue-17746-indented-code-then-nested-list.md

@@ -0,0 +1,3 @@
+-     a
+
+  - b

tests/format/markdown/list/issue-17746.md

@@ -0,0 +1,8 @@
+- a
+
+  - b
+
+- c
+
+
+  - d

tests/format/markdown/spec/__snapshots__/format.test.js.snap

@@ -1559,6 +1559,7 @@ proseWrap: "always"
 
 =====================================output=====================================
 1.  foo
+
     - bar
 
 ================================================================================
@@ -4464,6 +4465,7 @@ proseWrap: "always"
   \`\`\`
 
 - baz
+
   - \`\`\`
     foo
 

tests/format/mdx/mdx/__snapshots__/format.test.js.snap

@@ -376,6 +376,184 @@ opinionated-code-formatter-that-support-many-languages-and-integrate-with-most-e
 ================================================================================
 `;
 
+exports[`issue-17746.mdx - {"semi":false} format 1`] = `
+====================================options=====================================
+parsers: ["mdx"]
+printWidth: 80
+semi: false
+                                                                                | printWidth
+=====================================input======================================
+- a
+
+  - b
+
+- c
+
+
+  - d
+
+=====================================output=====================================
+- a
+
+  - b
+
+- c
+
+  - d
+
+================================================================================
+`;
+
+exports[`issue-17746.mdx format 1`] = `
+====================================options=====================================
+parsers: ["mdx"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+- a
+
+  - b
+
+- c
+
+
+  - d
+
+=====================================output=====================================
+- a
+
+  - b
+
+- c
+
+  - d
+
+================================================================================
+`;
+
+exports[`issue-17746-code-before-list.mdx - {"semi":false} format 1`] = `
+====================================options=====================================
+parsers: ["mdx"]
+printWidth: 80
+semi: false
+                                                                                | printWidth
+=====================================input======================================
+-     a
+  - b
+- c
+- d
+
+=====================================output=====================================
+-     a
+  - b
+- c
+- d
+
+================================================================================
+`;
+
+exports[`issue-17746-code-before-list.mdx format 1`] = `
+====================================options=====================================
+parsers: ["mdx"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+-     a
+  - b
+- c
+- d
+
+=====================================output=====================================
+-     a
+  - b
+- c
+- d
+
+================================================================================
+`;
+
+exports[`issue-17746-fenced-code-then-nested-list.mdx - {"semi":false} format 1`] = `
+====================================options=====================================
+parsers: ["mdx"]
+printWidth: 80
+semi: false
+                                                                                | printWidth
+=====================================input======================================
+- \`\`\`
+  a
+  \`\`\`
+
+  - b
+
+=====================================output=====================================
+- \`\`\`
+  a
+  \`\`\`
+
+  - b
+
+================================================================================
+`;
+
+exports[`issue-17746-fenced-code-then-nested-list.mdx format 1`] = `
+====================================options=====================================
+parsers: ["mdx"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+- \`\`\`
+  a
+  \`\`\`
+
+  - b
+
+=====================================output=====================================
+- \`\`\`
+  a
+  \`\`\`
+
+  - b
+
+================================================================================
+`;
+
+exports[`issue-17746-indented-code-then-nested-list.mdx - {"semi":false} format 1`] = `
+====================================options=====================================
+parsers: ["mdx"]
+printWidth: 80
+semi: false
+                                                                                | printWidth
+=====================================input======================================
+-     a
+
+  - b
+
+=====================================output=====================================
+-     a
+
+  - b
+
+================================================================================
+`;
+
+exports[`issue-17746-indented-code-then-nested-list.mdx format 1`] = `
+====================================options=====================================
+parsers: ["mdx"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+-     a
+
+  - b
+
+=====================================output=====================================
+-     a
+
+  - b
+
+================================================================================
+`;
+
 exports[`jsx.mdx - {"semi":false} format 1`] = `
 ====================================options=====================================
 parsers: ["mdx"]

tests/format/mdx/mdx/issue-17746-code-before-list.mdx

@@ -0,0 +1,4 @@
+-     a
+  - b
+- c
+- d

tests/format/mdx/mdx/issue-17746-fenced-code-then-nested-list.mdx

@@ -0,0 +1,5 @@
+- ```
+  a
+  ```
+
+  - b

tests/format/mdx/mdx/issue-17746-indented-code-then-nested-list.mdx

@@ -0,0 +1,3 @@
+-     a
+
+  - b

tests/format/mdx/mdx/issue-17746.mdx

@@ -0,0 +1,8 @@
+- a
+
+  - b
+
+- c
+
+
+  - d