Add rule MD056/table-column-count (fixes #92).

lib/configuration.d.ts

@@ -1070,6 +1070,14 @@ export interface Configuration {
          */
         style?: "consistent" | "leading_only" | "trailing_only" | "leading_and_trailing" | "no_leading_or_trailing";
       };
+  /**
+   * MD056/table-column-count : Table column count : https://github.com/DavidAnson/markdownlint/blob/v0.32.1/doc/md056.md
+   */
+  MD056?: boolean;
+  /**
+   * MD056/table-column-count : Table column count : https://github.com/DavidAnson/markdownlint/blob/v0.32.1/doc/md056.md
+   */
+  "table-column-count"?: boolean;
   /**
    * headings : MD001, MD003, MD018, MD019, MD020, MD021, MD022, MD023, MD024, MD025, MD026, MD036, MD041, MD043
    */
@@ -1163,7 +1171,7 @@ export interface Configuration {
    */
   images?: boolean;
   /**
-   * table : MD055
+   * table : MD055, MD056
    */
   table?: boolean;
   [k: string]: unknown;

lib/md056.js

@@ -0,0 +1,44 @@
+// @ts-check
+
+"use strict";
+
+const { addErrorDetailIf } = require("../helpers");
+const { filterByTypes } = require("../helpers/micromark.cjs");
+
+const makeRange = (start, end) => [ start, end - start + 1 ];
+
+module.exports = {
+  "names": [ "MD056", "table-column-count" ],
+  "description": "Table column count",
+  "tags": [ "table" ],
+  "function": function MD056(params, onError) {
+    const tables = filterByTypes(params.parsers.micromark.tokens, [ "table" ]);
+    for (const table of tables) {
+      const rows = filterByTypes(table.children, [ "tableDelimiterRow", "tableRow" ]);
+      let expectedCount = 0;
+      for (const row of rows) {
+        const cells = filterByTypes(row.children, [ "tableData", "tableDelimiter", "tableHeader" ]);
+        const actualCount = cells.length;
+        expectedCount ||= actualCount;
+        let detail = null;
+        let range = null;
+        if (actualCount < expectedCount) {
+          detail = "Too few cells, row will be missing data";
+          range = [ row.endColumn - 1, 1 ];
+        } else if (expectedCount < actualCount) {
+          detail = "Too many cells, extra data will be missing";
+          range = makeRange(cells[expectedCount].startColumn, row.endColumn - 1);
+        }
+        addErrorDetailIf(
+          onError,
+          row.endLine,
+          expectedCount,
+          actualCount,
+          detail,
+          null,
+          range
+        );
+      }
+    }
+  }
+}

lib/rules.js

@@ -6,9 +6,11 @@ const { homepage, version } = require("./constants");
 
 const rules = [
   require("./md001"),
+  // md002: Deprecated and removed
   require("./md003"),
   require("./md004"),
   require("./md005"),
+  // md006: Deprecated and removed
   require("./md007"),
   require("./md009"),
   require("./md010"),
@@ -52,8 +54,8 @@ const rules = [
   require("./md052"),
   require("./md053"),
   require("./md054"),
-  require("./md055")
-  // md056: See https://github.com/markdownlint/markdownlint
+  require("./md055"),
+  require("./md056")
   // md057: See https://github.com/markdownlint/markdownlint
 ];
 for (const rule of rules) {