bullet proof :)

dist/ast/mdast.js

@@ -23,11 +23,18 @@ function getMdast(markdown) {
 function getMarkdown(mdast) {
   return toMarkdown(mdast, {
     extensions: [frontmatterToMarkdown("yaml"), mdxToMarkdown(), gfmTableToMarkdown(), htmlCommentToMarkdown()],
+    listItemIndent: "one",
     join: [
       (__, _, parent) => {
         if (mdNodeIsJsxElement(parent)) {
           return 0;
         }
+        if (mdNodeIs(parent, "list")) {
+          return 0;
+        }
+        if (mdNodeIs(parent, "listItem")) {
+          return 0;
+        }
         return 1;
       }
     ]

experiments/test-fix.mjs

@@ -0,0 +1,38 @@
+import prettier from 'prettier';
+import { fromMarkdown } from 'mdast-util-from-markdown';
+import { toMarkdown } from 'mdast-util-to-markdown';
+
+const md = `The panel includes the following settings:
+
+* ON/OFF Toggle: A main switch.
+* Min Heating Time (1-60s): Minimum duration.
+* Mode: Selects the sequential heating algorithm:
+  * 0 - All: Cycles through all devices with time-based control.
+  * 1 - SP: Cycles through devices in groups.
+  * 2 - SP Any: Heats any devices that need heating.
+* Post-Heatup Mode: Mode to switch to after initial heatup phase.
+* Current Status: Display field showing the current state.`;
+
+const prettified = await prettier.format(md, {
+    parser: 'mdx',
+    printWidth: Infinity,
+    proseWrap: 'never',
+    useTabs: true
+});
+
+const tree = fromMarkdown(prettified);
+
+// FIX: also handle listItem parent in the join rule
+const result = toMarkdown(tree, {
+    listItemIndent: 'one',
+    join: [
+        (__, _, parent) => {
+            if (parent?.type === 'list') return 0;
+            if (parent?.type === 'listItem') return 0;
+            return 1;
+        }
+    ]
+});
+
+console.log('=== FIXED output ===');
+console.log(result);

experiments/test-prettier-list.mjs

@@ -0,0 +1,51 @@
+import prettier from 'prettier';
+import { fromMarkdown } from 'mdast-util-from-markdown';
+import { toMarkdown } from 'mdast-util-to-markdown';
+
+const md = `The panel includes the following settings:
+
+* ON/OFF Toggle: A main switch.
+* Min Heating Time (1-60s): Minimum duration.
+* Mode: Selects the sequential heating algorithm:
+  * 0 - All: Cycles through all devices with time-based control.
+  * 1 - SP: Cycles through devices in groups.
+  * 2 - SP Any: Heats any devices that need heating.
+* Post-Heatup Mode: Mode to switch to after initial heatup phase.
+* Current Status: Display field showing the current state.`;
+
+console.log('=== Input ===');
+console.log(md);
+
+const prettified = await prettier.format(md, {
+    parser: 'mdx',
+    printWidth: Infinity,
+    proseWrap: 'never',
+    useTabs: true
+});
+
+console.log('\n=== After Prettier ===');
+console.log(JSON.stringify(prettified));
+console.log(prettified);
+
+const tree = fromMarkdown(prettified);
+const list = tree.children[1]; // after the paragraph
+
+console.log('=== AST Analysis of list ===');
+console.log('list spread:', list.spread);
+for (const [i, item] of list.children.entries()) {
+    console.log(`item[${i}] spread:`, item.spread, 'children:', item.children.length, item.children.map(c => c.type));
+}
+
+// Now serialize with the join rule:
+const result = toMarkdown(tree, {
+    listItemIndent: 'one',
+    join: [
+        (__, _, parent) => {
+            if (parent?.type === 'list') return 0;
+            return 1;
+        }
+    ]
+});
+
+console.log('\n=== Serialized output ===');
+console.log(result);

experiments/test-spread.mjs

@@ -0,0 +1,50 @@
+import { fromMarkdown } from 'mdast-util-from-markdown';
+import { toMarkdown } from 'mdast-util-to-markdown';
+
+const md = `* Mode: Selects the algorithm:
+  * 0 - All: Cycles through all devices.
+  * 1 - SP: Cycles through devices in groups.
+* Post-Mode: blah`;
+
+const tree = fromMarkdown(md);
+const list = tree.children[0];
+
+console.log('=== AST Analysis ===');
+console.log('list spread:', list.spread);
+for (const [i, item] of list.children.entries()) {
+    console.log(`item[${i}] spread:`, item.spread, 'children count:', item.children.length, 'children types:', item.children.map(c => c.type));
+}
+
+console.log('\n=== Default toMarkdown ===');
+console.log(JSON.stringify(toMarkdown(tree)));
+
+console.log('\n=== With join rule ===');
+const result = toMarkdown(tree, {
+    listItemIndent: 'one',
+    join: [
+        (__, _, parent) => {
+            if (parent?.type === 'list') return 0;
+            if (parent?.type === 'listItem') return 0;
+            return 1;
+        }
+    ]
+});
+console.log(JSON.stringify(result));
+
+console.log('\n=== With join rule + forced spread=false ===');
+function clearSpread(node) {
+    if (node.spread !== undefined) node.spread = false;
+    if (node.children) node.children.forEach(clearSpread);
+}
+clearSpread(tree);
+const result2 = toMarkdown(tree, {
+    listItemIndent: 'one',
+    join: [
+        (__, _, parent) => {
+            if (parent?.type === 'list') return 0;
+            if (parent?.type === 'listItem') return 0;
+            return 1;
+        }
+    ]
+});
+console.log(JSON.stringify(result2));

package.json

@@ -18,6 +18,7 @@
 	},
 	"scripts": {
 		"build": "tsc && node build.js",
+		"dev": "tsc -w & node --watch build.js",
 		"test": "vitest run --reporter verbose",
 		"test:watch": "vitest watch --reporter verbose",
 		"test:tables": "vitest run src/__test__/e2e.test.ts --reporter verbose"

src/ast/mdast.ts

@@ -153,12 +153,21 @@ export function getMdast(markdown: string): MdRoot {
 export function getMarkdown(mdast: MdRoot): string {
 	return toMarkdown(mdast, {
 		extensions: [frontmatterToMarkdown('yaml'), mdxToMarkdown(), gfmTableToMarkdown(), htmlCommentToMarkdown()],
+		listItemIndent: 'one',
 		join: [
 			(__, _, parent) => {
 				if (mdNodeIsJsxElement(parent)) {
 					return 0;
 				}
 
+				// Keep list items tight (no blank lines between them)
+				if (mdNodeIs(parent, 'list')) {
+					return 0;
+				}
+				// Keep content within a list item tight (e.g. paragraph + nested sub-list)
+				if (mdNodeIs(parent, 'listItem')) {
+					return 0;
+				}
 				return 1;
 			}
 		]