Loosen table rules

1. allow one-column tables
2. allow mismatched column count

close https://github.com/markdown-it/markdown-it/issues/171

lib/rules_block/table.js

@@ -54,7 +54,7 @@ function escapedSplit(str) {
 
 
 module.exports = function table(state, startLine, endLine, silent) {
-  var ch, lineText, pos, i, nextLine, rows, token,
+  var ch, lineText, pos, i, nextLine, columns, columnCount, token,
       aligns, t, tableLines, tbodyLines;
 
   // should have at least three lines
@@ -75,15 +75,14 @@ module.exports = function table(state, startLine, endLine, silent) {
   lineText = getLine(state, startLine + 1);
   if (!/^[-:| ]+$/.test(lineText)) { return false; }
 
-  rows = lineText.split('|');
-  if (rows.length < 2) { return false; }
+  columns = lineText.split('|');
   aligns = [];
-  for (i = 0; i < rows.length; i++) {
-    t = rows[i].trim();
+  for (i = 0; i < columns.length; i++) {
+    t = columns[i].trim();
     if (!t) {
       // allow empty columns before and after table, but not in between columns;
       // e.g. allow ` |---| `, disallow ` ---||--- `
-      if (i === 0 || i === rows.length - 1) {
+      if (i === 0 || i === columns.length - 1) {
         continue;
       } else {
         return false;
@@ -102,8 +101,13 @@ module.exports = function table(state, startLine, endLine, silent) {
 
   lineText = getLine(state, startLine).trim();
   if (lineText.indexOf('|') === -1) { return false; }
-  rows = escapedSplit(lineText.replace(/^\||\|$/g, ''));
-  if (aligns.length !== rows.length) { return false; }
+  columns = escapedSplit(lineText.replace(/^\||\|$/g, ''));
+
+  // header row will define an amount of columns in the entire table,
+  // and align row shouldn't be smaller than that (the rest of the rows can)
+  columnCount = columns.length;
+  if (columnCount > aligns.length) { return false; }
+
   if (silent) { return true; }
 
   token     = state.push('table_open', 'table', 1);
@@ -115,7 +119,7 @@ module.exports = function table(state, startLine, endLine, silent) {
   token     = state.push('tr_open', 'tr', 1);
   token.map = [ startLine, startLine + 1 ];
 
-  for (i = 0; i < rows.length; i++) {
+  for (i = 0; i < columns.length; i++) {
     token          = state.push('th_open', 'th', 1);
     token.map      = [ startLine, startLine + 1 ];
     if (aligns[i]) {
@@ -123,7 +127,7 @@ module.exports = function table(state, startLine, endLine, silent) {
     }
 
     token          = state.push('inline', '', 0);
-    token.content  = rows[i].trim();
+    token.content  = columns[i].trim();
     token.map      = [ startLine, startLine + 1 ];
     token.children = [];
 
@@ -141,20 +145,17 @@ module.exports = function table(state, startLine, endLine, silent) {
 
     lineText = getLine(state, nextLine).trim();
     if (lineText.indexOf('|') === -1) { break; }
-    rows = escapedSplit(lineText.replace(/^\||\|$/g, ''));
-
-    // set number of columns to number of columns in header row
-    rows.length = aligns.length;
+    columns = escapedSplit(lineText.replace(/^\||\|$/g, ''));
 
     token = state.push('tr_open', 'tr', 1);
-    for (i = 0; i < rows.length; i++) {
+    for (i = 0; i < columnCount; i++) {
       token          = state.push('td_open', 'td', 1);
       if (aligns[i]) {
         token.attrs  = [ [ 'style', 'text-align:' + aligns[i] ] ];
       }
 
       token          = state.push('inline', '', 0);
-      token.content  = rows[i] ? rows[i].trim() : '';
+      token.content  = columns[i] ? columns[i].trim() : '';
       token.children = [];
 
       token          = state.push('td_close', 'td', -1);

test/fixtures/markdown-it/tables.txt

@@ -225,18 +225,6 @@ bar|bar</p>
 .
 
 
-Title line should have correct column count:
-.
-foo|foo
----|---|---
-bar|bar
-.
-<p>foo|foo
-—|---|—
-bar|bar</p>
-.
-
-
 Should terminate paragraph:
 .
 paragraph
@@ -390,54 +378,94 @@ Another complicated backticks case
 .
 
 
-Add/remove columns to match the first row:
+Should be parsed before code blocks:
 .
-Heading 1|Heading 2|Heading 3
----|---|---
-1|2
-1|2|3|4
+    foo | bar
+  ----- | -----
+    aaa | bbb
 .
 <table>
 <thead>
 <tr>
-<th>Heading 1</th>
-<th>Heading 2</th>
-<th>Heading 3</th>
+<th>foo</th>
+<th>bar</th>
 </tr>
 </thead>
 <tbody>
 <tr>
-<td>1</td>
-<td>2</td>
-<td></td>
+<td>aaa</td>
+<td>bbb</td>
 </tr>
+</tbody>
+</table>
+.
+
+
+An amount of rows might be different across the table (issue #171):
+.
+| 1 | 2 |
+| :-----: |  :-----: |  :-----: |
+| 3 | 4 | 5 | 6 |
+.
+<table>
+<thead>
 <tr>
-<td>1</td>
-<td>2</td>
-<td>3</td>
+<th style="text-align:center">1</th>
+<th style="text-align:center">2</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td style="text-align:center">3</td>
+<td style="text-align:center">4</td>
 </tr>
 </tbody>
 </table>
 .
 
 
-Should be parsed before code blocks:
+An amount of rows might be different across the table #2:
 .
-    foo | bar
-  ----- | -----
-    aaa | bbb
+| 1 | 2 | 3 | 4 |
+| :-----: |  :-----: |  :-----: |  :-----: |
+| 5 | 6 |
 .
 <table>
 <thead>
 <tr>
-<th>foo</th>
-<th>bar</th>
+<th style="text-align:center">1</th>
+<th style="text-align:center">2</th>
+<th style="text-align:center">3</th>
+<th style="text-align:center">4</th>
 </tr>
 </thead>
 <tbody>
 <tr>
-<td>aaa</td>
-<td>bbb</td>
+<td style="text-align:center">5</td>
+<td style="text-align:center">6</td>
+<td style="text-align:center"></td>
+<td style="text-align:center"></td>
+</tr>
+</tbody>
+</table>
+.
+
+
+Allow one-column tables (issue #171):
+.
+| foo |
+:-----:
+| bar |
+.
+<table>
+<thead>
+<tr>
+<th style="text-align:center">foo</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td style="text-align:center">bar</td>
 </tr>
 </tbody>
 </table>