fix: split non-parameter items from typed lists in signature tables (#1023)

* fix: split non-parameter items from typed lists in signature tables


Co-authored-by: Aviv Keller <me@aviv.sh>

Author: btea

.changeset/fix-typed-list-split.md

@@ -0,0 +1,10 @@
+---
+'@doc-kit/core': patch
+'@doc-kit/generator-react': patch
+---
+
+Fix empty paragraphs in API docs when a typed parameter list contains trailing non-parameter items
+
+When a loose markdown list in the API docs starts with typed parameters (e.g. `actual`, `expected`, `Returns`) but also contains plain prose bullets (e.g. algorithm complexity notes), the entire list was previously treated as a parameter signature table. The non-parameter items had no name or type, causing them to render as empty `<section>` blocks on the built site.
+
+The fix splits the list at the first non-parameter item: typed items become the `FunctionSignature` table, and the remaining items render as regular markdown content.

packages/core/src/utils/queries/__tests__/index.test.mjs

@@ -178,4 +178,67 @@ describe('UNIST', () => {
       });
     });
   });
+
+  describe('isTypedListItem', () => {
+    it('returns false for undefined/null items', () => {
+      strictEqual(UNIST.isTypedListItem(undefined), false);
+      strictEqual(UNIST.isTypedListItem(null), false);
+    });
+
+    it('returns false for items without children', () => {
+      strictEqual(UNIST.isTypedListItem({}), false);
+    });
+
+    const cases = [
+      {
+        name: 'inlineCode with valid property name',
+        item: createTree('listItem', [
+          createTree('paragraph', [
+            createTree('inlineCode', 'actual'),
+            createTree('text', ' '),
+            createTree('typeAnnotation', 'Array|string'),
+          ]),
+        ]),
+        expected: true,
+      },
+      {
+        name: 'Returns prefix',
+        item: createTree('listItem', [
+          createTree('paragraph', [createTree('text', 'Returns: some value')]),
+        ]),
+        expected: true,
+      },
+      {
+        name: 'direct type annotation',
+        item: createTree('listItem', [
+          createTree('paragraph', [createTree('typeAnnotation', 'Type')]),
+        ]),
+        expected: true,
+      },
+      {
+        name: 'plain prose text (no typed prefix)',
+        item: createTree('listItem', [
+          createTree('paragraph', [
+            createTree('text', 'Algorithm complexity: O(N*D), where:'),
+          ]),
+        ]),
+        expected: false,
+      },
+      {
+        name: 'inlineCode with invalid property name',
+        item: createTree('listItem', [
+          createTree('paragraph', [
+            createTree('inlineCode', 'not a valid prop'),
+          ]),
+        ]),
+        expected: false,
+      },
+    ];
+
+    cases.forEach(({ name, item, expected }) => {
+      it(`returns ${expected} for ${name}`, () => {
+        strictEqual(UNIST.isTypedListItem(item), expected);
+      });
+    });
+  });
 });

packages/core/src/utils/queries/index.mjs

@@ -1,7 +1,7 @@
 'use strict';
 
 import { transformNodesToString } from '../unist.mjs';
-import { isTypedList } from './utils.mjs';
+import { isTypedListItem, isTypedList } from './utils.mjs';
 
 // This defines the actual REGEX Queries
 export const QUERIES = {
@@ -71,6 +71,12 @@ export const UNIST = {
    */
   isLooselyTypedList: list => Boolean(isTypedList(list)),
 
+  /**
+   * @param {import('@types/mdast').ListItem} item
+   * @returns {boolean}
+   */
+  isTypedListItem,
+
   /**
    * @param {import('@types/mdast').List} list
    * @returns {boolean}

packages/core/src/utils/queries/utils.mjs

@@ -2,20 +2,17 @@ import { VALID_JAVASCRIPT_PROPERTY } from './constants.mjs';
 import { QUERIES } from './index.mjs';
 
 /**
- * @param {import('@types/mdast').List} list
+ * Inspects the first phrasing node of a paragraph and returns how confidently
+ * it looks like the start of a typed parameter.
+ *
+ * @param {import('@types/mdast').PhrasingContent | undefined} firstNode
  * @returns {0 | 1 | 2} confidence
  *
- * 0: This is not a typed list
- * 1: This is a loosely typed list
- * 2: This is a strongly typed list
+ * 0: Not a typed parameter
+ * 1: Loosely typed (inlineCode + valid property name)
+ * 2: Strongly typed (typed list starter or direct type annotation)
  */
-export const isTypedList = list => {
-  if (!list || list.type !== 'list') {
-    return 0;
-  }
-
-  const firstNode = list.children?.[0]?.children?.[0]?.children[0];
-
+const getTypedConfidence = firstNode => {
   if (!firstNode) {
     return 0;
   }
@@ -43,3 +40,30 @@ export const isTypedList = list => {
 
   return 0;
 };
+
+/**
+ * Checks whether a single list item looks like a typed parameter — i.e. it
+ * starts with a property name (`inlineCode`), a Returns/Extends/Type prefix,
+ * or a direct type annotation.
+ *
+ * @param {import('@types/mdast').ListItem} item
+ * @returns {boolean}
+ */
+export const isTypedListItem = item =>
+  Boolean(getTypedConfidence(item?.children?.[0]?.children?.[0]));
+
+/**
+ * @param {import('@types/mdast').List} list
+ * @returns {0 | 1 | 2} confidence
+ *
+ * 0: This is not a typed list
+ * 1: This is a loosely typed list
+ * 2: This is a strongly typed list
+ */
+export const isTypedList = list => {
+  if (!list || list.type !== 'list') {
+    return 0;
+  }
+
+  return getTypedConfidence(list.children?.[0]?.children?.[0]?.children?.[0]);
+};

packages/react/src/jsx-ast/utils/buildContent.mjs

@@ -264,11 +264,33 @@ export const processEntry = entry => {
   // Transform typed lists into property tables. Skipped for MDX pages, whose
   // lists are authored prose rather than API type signatures.
   if (!entry.mdx) {
-    visit(
-      entry.content,
-      UNIST.isStronglyTypedList,
-      (node, idx, parent) => (parent.children[idx] = createSignatureTable(node))
-    );
+    visit(entry.content, UNIST.isStronglyTypedList, (node, idx, parent) => {
+      // A typed list may contain trailing non-parameter items (e.g. prose
+      // bullets that happen to share the same loose list in the source
+      // markdown). Split those off so they render as regular content instead
+      // of being silently swallowed by the signature table.
+      const firstNonTyped = node.children.findIndex(
+        item => !UNIST.isTypedListItem(item)
+      );
+
+      if (firstNonTyped === -1) {
+        parent.children[idx] = createSignatureTable(node);
+        return;
+      }
+
+      const typedItems = node.children.slice(0, firstNonTyped);
+      const restItems = node.children.slice(firstNonTyped);
+
+      const replacements = [];
+      if (typedItems.length > 0) {
+        replacements.push(
+          createSignatureTable({ ...node, children: typedItems })
+        );
+      }
+      replacements.push({ ...node, children: restItems });
+
+      parent.children.splice(idx, 1, ...replacements);
+    });
   }
 
   return entry.content;