fix: single column table (#2985)

src/Tokenizer.ts

@@ -399,13 +399,18 @@ export class _Tokenizer {
   table(src: string): Tokens.Table | undefined {
     const cap = this.rules.block.table.exec(src);
     if (cap) {
+      if (!/[:|]/.test(cap[2])) {
+        // delimiter row must have a pipe (|) or colon (:) otherwise it is a setext heading
+        return;
+      }
+
       const item: Tokens.Table = {
         type: 'table',
         raw: cap[0],
         header: splitCells(cap[1]).map(c => {
           return { text: c, tokens: [] };
         }),
-        align: cap[2].replace(/^ *|\| *$/g, '').split(/ *\| */),
+        align: cap[2].replace(/^\||\| *$/g, '').split('|'),
         rows: cap[3] && cap[3].trim() ? cap[3].replace(/\n[ \t]*$/, '').split('\n') : []
       };
 

src/rules.ts

@@ -157,8 +157,8 @@ block.normal = { ...block };
 
 block.gfm = {
   ...block.normal,
-  table: '^ *([^\\n ].*\\|.*)\\n' // Header
-    + ' {0,3}(?:\\| *)?(:?-+:? *(?:\\| *:?-+:? *)*)(?:\\| *)?' // Align
+  table: '^ *([^\\n ].*)\\n' // Header
+    + ' {0,3}((?:\\| *)?:?-+:? *(?:\\| *:?-+:? *)*(?:\\| *)?)' // Align
     + '(?:\\n((?:(?! *\\n|hr|heading|blockquote|code|fences|list|html).*(?:\\n|$))*)\\n*|$)' // Cells
 };
 

test/specs/new/table_vs_setext.html

@@ -0,0 +1,46 @@
+<h2>| setext |</h2>
+<p>| setext |</p>
+
+<h2>setext</h2>
+<p>setext</p>
+
+<table>
+  <thead>
+    <tr>
+      <th align="left">table</th>
+    </tr>
+  </thead>
+  <tbody>
+    <tr>
+      <td align="left">table</td>
+    </tr>
+  </tbody>
+</table>
+
+<table>
+  <thead>
+    <tr>
+      <th align="left">table</th>
+    </tr>
+  </thead>
+  <tbody>
+    <tr>
+      <td align="left">table</td>
+    </tr>
+  </tbody>
+</table>
+
+<table>
+  <thead>
+    <tr>
+      <th>table</th>
+    </tr>
+  </thead>
+  <tbody>
+    <tr>
+      <td>table</td>
+    </tr>
+  </tbody>
+</table>
+
+

test/specs/new/table_vs_setext.md

@@ -0,0 +1,22 @@
+---
+gfm: true
+---
+| setext |
+----------
+| setext |
+
+setext
+------
+setext
+
+| table |
+:--------
+| table |
+
+table
+:----
+table
+
+| table |
+|--------
+| table |