feat: keep list item gaps as written

.changeset/list-blank-before.md

@@ -0,0 +1,6 @@
+---
+'@meowdown/markdown': minor
+'@meowdown/core': minor
+---
+
+Keep the blank lines between list items and around nested lists as written.

packages/core/src/converters/ast-to-pm.ts

@@ -40,6 +40,7 @@ export function astToDoc(
           marker: node.marker ?? null,
           taskMarker: node.taskMarker,
           markerGap: node.markerGap,
+          blankBefore: node.blankBefore ?? null,
         },
         children,
       )

packages/core/src/converters/md-to-pm.test.ts

@@ -212,6 +212,7 @@ describe('markdownToDoc', () => {
             marker: '-',
             taskMarker: null,
             markerGap: 1,
+            blankBefore: null,
           },
           content: [{ type: 'paragraph', content: [{ type: 'text', text: 'one' }] }],
         },
@@ -225,6 +226,7 @@ describe('markdownToDoc', () => {
             marker: '-',
             taskMarker: null,
             markerGap: 1,
+            blankBefore: false,
           },
           content: [{ type: 'paragraph', content: [{ type: 'text', text: 'two' }] }],
         },
@@ -276,6 +278,7 @@ describe('markdownToDoc', () => {
             marker: '.',
             taskMarker: null,
             markerGap: 1,
+            blankBefore: null,
           },
           content: [{ type: 'paragraph', content: [{ type: 'text', text: 'five' }] }],
         },
@@ -289,6 +292,7 @@ describe('markdownToDoc', () => {
             marker: '.',
             taskMarker: null,
             markerGap: 1,
+            blankBefore: false,
           },
           content: [{ type: 'paragraph', content: [{ type: 'text', text: 'six' }] }],
         },
@@ -311,6 +315,7 @@ describe('markdownToDoc', () => {
             marker: '-',
             taskMarker: null,
             markerGap: 1,
+            blankBefore: null,
           },
           content: [{ type: 'paragraph', content: [{ type: 'text', text: 'todo' }] }],
         },
@@ -333,6 +338,7 @@ describe('markdownToDoc', () => {
             marker: '-',
             taskMarker: 'x',
             markerGap: 1,
+            blankBefore: null,
           },
           content: [{ type: 'paragraph', content: [{ type: 'text', text: 'done' }] }],
         },
@@ -356,6 +362,7 @@ describe('markdownToDoc', () => {
             marker: '-',
             taskMarker: 'x',
             markerGap: 1,
+            blankBefore: null,
           },
           content: [{ type: 'paragraph', content: [{ type: 'text', text: 'Square Task' }] }],
         },
@@ -369,6 +376,7 @@ describe('markdownToDoc', () => {
             marker: '+',
             taskMarker: null,
             markerGap: 1,
+            blankBefore: true,
           },
           content: [{ type: 'paragraph', content: [{ type: 'text', text: 'Circle Task' }] }],
         },
@@ -405,6 +413,7 @@ describe('markdownToDoc', () => {
             marker: '.',
             taskMarker: null,
             markerGap: 1,
+            blankBefore: null,
           },
           content: [{ type: 'paragraph', content: [{ type: 'text', text: '[x] done' }] }],
         },
@@ -458,6 +467,7 @@ describe('markdownToDoc', () => {
             marker: '-',
             taskMarker: null,
             markerGap: 1,
+            blankBefore: null,
           },
           content: [
             { type: 'paragraph', content: [{ type: 'text', text: 'x' }] },
@@ -685,6 +695,7 @@ describe('markdownToDoc', () => {
             marker: '*',
             taskMarker: null,
             markerGap: 1,
+            blankBefore: null,
           },
           content: [{ type: 'paragraph', content: [{ type: 'text', text: 'star' }] }],
         },
@@ -707,6 +718,7 @@ describe('markdownToDoc', () => {
             marker: ')',
             taskMarker: null,
             markerGap: 1,
+            blankBefore: null,
           },
           content: [{ type: 'paragraph', content: [{ type: 'text', text: 'paren' }] }],
         },
@@ -729,6 +741,7 @@ describe('markdownToDoc', () => {
             marker: '.',
             taskMarker: null,
             markerGap: 1,
+            blankBefore: null,
           },
           content: [{ type: 'paragraph', content: [{ type: 'text', text: 'zero' }] }],
         },
@@ -751,6 +764,7 @@ describe('markdownToDoc', () => {
             marker: '-',
             taskMarker: 'X',
             markerGap: 1,
+            blankBefore: null,
           },
           content: [{ type: 'paragraph', content: [{ type: 'text', text: 'upper' }] }],
         },
@@ -989,6 +1003,7 @@ describe('markdownToDoc', () => {
             marker: '-',
             taskMarker: null,
             markerGap: 1,
+            blankBefore: null,
           },
           content: [
             { type: 'paragraph', content: [{ type: 'text', text: 'x' }] },

packages/core/src/converters/pm-to-ast.ts

@@ -72,6 +72,7 @@ function readBlock(node: ProseMirrorNode): MarkdownBlock {
         marker: attrs.marker ?? undefined,
         taskMarker: attrs.taskMarker ?? undefined,
         markerGap: attrs.markerGap,
+        blankBefore: attrs.blankBefore ?? undefined,
         children: readBlocks(node),
       }
     }

packages/core/src/converters/pm-to-md.test.ts

@@ -197,6 +197,15 @@ describe('docToMarkdown', () => {
     expect(markdown).toBe('- first\n\n  second\n\n- third\n')
   })
 
+  it('continues the gap of the item above it', () => {
+    const doc = n.doc(
+      n.list({ kind: 'bullet' }, n.paragraph('a')),
+      n.list({ kind: 'bullet', blankBefore: true }, n.paragraph('b')),
+      n.list({ kind: 'bullet' }, n.paragraph('c')),
+    )
+    expect(docToMarkdown(doc)).toBe('- a\n\n- b\n\n- c\n')
+  })
+
   it('keeps a blank line after a list', () => {
     const doc = n.doc(n.list({ kind: 'bullet' }, n.paragraph('item')), n.paragraph('after'))
     const markdown = docToMarkdown(doc)

packages/core/src/converters/roundtrip.test.ts

@@ -453,7 +453,7 @@ describe('bullet lists', () => {
     expect(roundtrip('- a\n    - deep')).toBe('- a\n  - deep\n')
   })
 
-  it.fails('keeps a loose list', () => {
+  it('keeps a loose list', () => {
     const md = ['- a', '', '- b'].join('\n')
     expect(roundtrip(md)).toBe(md + '\n')
   })
@@ -466,12 +466,12 @@ describe('bullet lists', () => {
     expect(roundtrip('- a\n- \n- b')).toBe('- a\n-\n- b\n')
   })
 
-  it.fails('keeps a tight sibling after a two-block item', () => {
+  it('keeps a tight sibling after a two-block item', () => {
     const md = ['- a', '', '  b', '- c'].join('\n')
     expect(roundtrip(md)).toBe(md + '\n')
   })
 
-  it.fails('keeps a nested list right under its paragraph in a loose list', () => {
+  it('keeps a nested list right under its paragraph in a loose list', () => {
     const md = ['- a', '', '  b', '- c', '  - d'].join('\n')
     expect(roundtrip(md)).toBe(md + '\n')
   })
@@ -1071,7 +1071,7 @@ describe('mixed structures', () => {
     expect(roundtrip('# h1\n## h2\n### h3')).toBe('# h1\n## h2\n### h3\n')
   })
 
-  it.fails('keeps a list right under a paragraph', () => {
+  it('keeps a list right under a paragraph', () => {
     expect(roundtrip('para\n- a')).toBe('para\n- a\n')
   })
 

packages/core/src/converters/sample-content.ts

@@ -71,6 +71,7 @@ export const sampleContent: NodeJSON = {
         marker: '-',
         taskMarker: null,
         markerGap: 1,
+        blankBefore: true,
       },
       content: [
         {
@@ -89,6 +90,7 @@ export const sampleContent: NodeJSON = {
         marker: '-',
         taskMarker: null,
         markerGap: 1,
+        blankBefore: false,
       },
       content: [
         {
@@ -105,6 +107,7 @@ export const sampleContent: NodeJSON = {
             marker: '-',
             taskMarker: null,
             markerGap: 1,
+            blankBefore: false,
           },
           content: [
             {
@@ -130,6 +133,7 @@ export const sampleContent: NodeJSON = {
         marker: '.',
         taskMarker: null,
         markerGap: 1,
+        blankBefore: true,
       },
       content: [
         {
@@ -148,6 +152,7 @@ export const sampleContent: NodeJSON = {
         marker: '.',
         taskMarker: null,
         markerGap: 1,
+        blankBefore: false,
       },
       content: [
         {

packages/core/src/extensions/extension.test.ts

@@ -71,6 +71,7 @@ describe('defineEditorExtension', () => {
           },
           {
             "attrs": {
+              "blankBefore": null,
               "checked": false,
               "collapsed": false,
               "kind": "bullet",
@@ -94,6 +95,7 @@ describe('defineEditorExtension', () => {
           },
           {
             "attrs": {
+              "blankBefore": null,
               "checked": false,
               "collapsed": false,
               "kind": "ordered",
@@ -117,6 +119,7 @@ describe('defineEditorExtension', () => {
           },
           {
             "attrs": {
+              "blankBefore": null,
               "checked": false,
               "collapsed": false,
               "kind": "task",

packages/core/src/extensions/list.ts

@@ -77,6 +77,7 @@ export interface MeowdownListAttrs extends ListAttrs {
   marker?: ListMarker | undefined
   taskMarker?: TaskMarker | undefined
   markerGap?: number | undefined
+  blankBefore?: boolean | null | undefined
 }
 
 // Each attr persists only its non-canonical values (`.`, `-`, `x`, and a gap
@@ -165,6 +166,22 @@ function defineListMarkerGapAttr(): ListMarkerGapExtension {
   })
 }
 
+type ListBlankBeforeExtension = Extension<{
+  Nodes: { list: { blankBefore?: boolean | null | undefined } }
+}>
+
+/**
+ * Whether one blank line separated the item from the sibling before it in the
+ * Markdown source. `null` leaves the gap to the serializer.
+ */
+function defineListBlankBeforeAttr(): ListBlankBeforeExtension {
+  return defineNodeAttr<'list', 'blankBefore', boolean | null>({
+    type: 'list' satisfies NodeName,
+    attr: 'blankBefore',
+    default: null,
+  })
+}
+
 function getListClipboardAttributes(node: ProseMirrorNode): Record<string, string | undefined> {
   const attrs = node.attrs as MeowdownListAttrs
   return {
@@ -529,6 +546,7 @@ export function defineMeowdownList() {
     defineListMarkerAttr(),
     defineListTaskMarkerAttr(),
     defineListMarkerGapAttr(),
+    defineListBlankBeforeAttr(),
     defineMeowdownListCommands(),
   )
 }

packages/core/src/extensions/wililink-fuzz.test.tsx

@@ -129,7 +129,6 @@ describe('caret fuzz over a wikilink outline in focus mode', () => {
         - [[bar]]
       ----- markdown after -------------
       top
-
       - [[foo]]
       - [[bar]]
       ----- selection before/after -----
@@ -204,7 +203,6 @@ describe('caret fuzz over a wikilink outline in focus mode', () => {
       - top
 
         [[foo]]
-
         - [[bar]]
       ----- selection before/after -----
       top
@@ -359,7 +357,6 @@ describe('caret fuzz over a wikilink outline in focus mode', () => {
         - [[bar]]
       ----- markdown after -------------
       - top
-
         - [[foo]]
 
         [[bar]]
@@ -1330,7 +1327,6 @@ describe('caret fuzz over a wikilink outline in hide mode', () => {
         - [[bar]]
       ----- markdown after -------------
       top
-
       - [[foo]]
       - [[bar]]
       ----- selection before/after -----
@@ -1405,7 +1401,6 @@ describe('caret fuzz over a wikilink outline in hide mode', () => {
       - top
 
         [[foo]]
-
         - [[bar]]
       ----- selection before/after -----
       top
@@ -1560,7 +1555,6 @@ describe('caret fuzz over a wikilink outline in hide mode', () => {
         - [[bar]]
       ----- markdown after -------------
       - top
-
         - [[foo]]
 
         [[bar]]

packages/markdown/src/ast/check-roundtrip.test.ts

@@ -121,20 +121,23 @@ const EXACT_CASES: string[] = [
 
   // a no-break space is heading text, not the gap around a closing `#` run
   '# #\u{A0}',
-]
 
-const NORMALIZING_CASES: string[] = [
-  // a loose list serializes tight
+  // a loose list stays loose, and a tight list after a two-block item tight
   '- a\n\n- b',
+  '1. a\n\n2. b',
+  '- a\n\n  b\n- c',
+
+  // a list starts right under a paragraph, in a blockquote too
+  'para\n- a',
+  '> text\n> - item',
+  '> a\n> - x\n> - y',
+]
 
+const NORMALIZING_CASES: string[] = [
   // the items of an ordered list are numbered in sequence
   '1. a\n1. b\n1. c',
   '3) a\n7) b',
 
-  // a blockquote gains an empty `>` line before a following list
-  '> text\n> - item',
-  '> a\n> - x\n> - y',
-
   // a lazy continuation gains the canonical item indent
   '- [ ] todo\neen voorlopig idee',
   '- item\nlazy line',

packages/markdown/src/ast/equal.ts

@@ -57,7 +57,8 @@ function isListItemEqual(a: MarkdownListItem, b: MarkdownListItem): boolean {
     a.collapsed === b.collapsed &&
     a.marker === b.marker &&
     a.taskMarker === b.taskMarker &&
-    a.markerGap === b.markerGap
+    a.markerGap === b.markerGap &&
+    a.blankBefore === b.blankBefore
   )
 }