Update MD013 to allow excluding code and tables.

doc/Rules.md

@@ -266,7 +266,7 @@ lines inside code blocks.
 
 Tags: line_length
 
-Parameters: line_length (number; default 80)
+Parameters: line_length, code_blocks, tables (number; default 80, boolean; default true)
 
 This rule is triggered when there are lines that are longer than the
 configured line length (default: 80 characters). To fix this, split the line
@@ -276,6 +276,13 @@ This rule has an exception where there is no whitespace beyond the configured
 line length. This allows you to still include items such as long URLs without
 being forced to break them in the middle.
 
+You also have the option to exclude this rule for code blocks and tables. To
+do this, set the `code_blocks` and/or `tables` parameters to false.
+
+Code blocks are included in this rule by default since it is often a
+requirement for document readability, and tentatively compatible with code
+rules. Still, some languages do not lend themselves to short lines.
+
 ## MD014 - Dollar signs used before commands without showing output
 
 Tags: code

lib/rules.js

@@ -49,7 +49,7 @@ function forEachLine(params, callback) {
       var fence = match && match[1];
       if (fence &&
           (!inFence || (fence.substr(0, fenceStart.length) === fenceStart))) {
-        metadata = inFence ? -2 : 2;
+        metadata = inFence ? 2 : 6;
         fenceStart = inFence ? null : fence;
         inFence = !inFence;
       } else if (inFence) {
@@ -63,12 +63,23 @@ function forEachLine(params, callback) {
         lineMetadata[i] = 1;
       }
     });
+    // Find tables normally
+    filterTokens(params, "table_open", function forToken(token) {
+      for (var i = token.map[0]; i < token.map[1]; i++) {
+        lineMetadata[i] += 8;
+      }
+    });
     params.forEachLine = lineMetadata;
   }
   // Invoke callback
   params.lines.forEach(function forLine(line, lineIndex) {
     var metadata = params.forEachLine[lineIndex];
-    callback(line, lineIndex, !!metadata, (metadata >> 1));
+    callback(
+      line,
+      lineIndex,
+      !!(metadata & 7),
+      (((metadata & 6) >> 1) || 2) - 2,
+      !!(metadata & 8));
   });
 }
 
@@ -326,9 +337,16 @@ module.exports = [
     "tags": [ "line_length" ],
     "func": function MD013(params, errors) {
       var lineLength = params.options.line_length || 80;
+      var codeBlocks = params.options.code_blocks;
+      var includeCodeBlocks = (codeBlocks === undefined) ? true : !!codeBlocks;
+      var tables = params.options.tables;
+      var includeTables = (tables === undefined) ? true : !!tables;
       var re = new RegExp("^.{" + lineLength + "}.*\\s");
-      params.lines.forEach(function forLine(line, lineIndex) {
-        if (re.test(line)) {
+      forEachLine(params,
+        function forLine(line, lineIndex, inCode, onFence, inTable) {
+          if ((includeCodeBlocks || !inCode) &&
+              (includeTables || !inTable) &&
+              re.test(line)) {
             errors.push(lineIndex + 1);
           }
         });

test/long_lines_code-default.md

@@ -0,0 +1,28 @@
+This is a short line.
+
+This is a very very very very very very very very very very very very very very very very very very very very long line. {MD013}
+
+This is a short line.
+
+```text
+Here is a short line in a code block.
+Here is a very very very very very very very very very very very very very very very very very very very long line in a code block. {MD013}
+```
+
+This is a short line.
+
+| First Header  | Second Header | Third Header  | Fourth Header | Fifth Header  | Sixth  Header | {MD013}
+| ------------- | ------------- | ------------- | ------------- | ------------- | ------------- | {MD013}
+| Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  | {MD013}
+| ============= | ============= | ============= | ============= | ============= | ============= | {MD013}
+| Footer Cell   | Footer Cell   | Footer Cell   | Footer Cell   | Footer Cell   | Footer Cell   | {MD013}
+
+This is a very very very very very very very very very very very very very very very very very very very very long line. {MD013}
+
+Another line.
+
+| First Header  | Second Header | Third Header  | Fourth Header | Fifth Header  | Sixth  Header | {MD013}
+| ------------- | ------------- | ------------- | ------------- | ------------- | ------------- | {MD013}
+| Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  | {MD013}
+| ============= | ============= | ============= | ============= | ============= | ============= | {MD013}
+| Footer Cell   | Footer Cell   | Footer Cell   | Footer Cell   | Footer Cell   | Footer Cell   | {MD013}

test/long_lines_code.json

@@ -0,0 +1,7 @@
+{
+  "default": true,
+  "MD013": {
+    "code_blocks": false,
+    "tables": false
+  }
+}

test/long_lines_code.md

@@ -0,0 +1,38 @@
+This is a short line.
+
+This is a very very very very very very very very very very very very very very very very very very very very long line. {MD013}
+
+This is a short line.
+
+```text
+Here is a short line in a code block.
+Here is a very very very very very very very very very very very very very very very very very very very long line in a code block.
+```
+
+This is a short line.
+
+| First Header  | Second Header | Third Header  | Fourth Header | Fifth Header  | Sixth  Header |
+| ------------- | ------------- | ------------- | ------------- | ------------- | ------------- |
+| Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  |
+| Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  |
+| ------------- | ------------- | ------------- | ------------- | ------------- | ------------- |
+| Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  |
+| Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  |
+| ============= | ============= | ============= | ============= | ============= | ============= |
+| Footer Cell   | Footer Cell   | Footer Cell   | Footer Cell   | Footer Cell   | Footer Cell   |
+{: rules="groups"}
+
+This is a very very very very very very very very very very very very very very very very very very very very long line. {MD013}
+
+Another line.
+
+| First Header  | Second Header | Third Header  | Fourth Header | Fifth Header  | Sixth  Header |
+| ------------- | ------------- | ------------- | ------------- | ------------- | ------------- |
+| Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  |
+| Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  |
+| ------------- | ------------- | ------------- | ------------- | ------------- | ------------- |
+| Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  |
+| Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  | Content Cell  |
+| ============= | ============= | ============= | ============= | ============= | ============= |
+| Footer Cell   | Footer Cell   | Footer Cell   | Footer Cell   | Footer Cell   | Footer Cell   |
+{: rules="groups"}