Update MD004/ul-style to auto-fix violations (fixes #351).

demo/markdownlint-browser.js

@@ -703,8 +703,9 @@ module.exports.applyFixes = function applyFixes(input, errors) {
         var lineIndex = lineNumber - 1;
         var editIndex = editColumn - 1;
         if ((lineIndex !== lastLineIndex) ||
-            ((editIndex + deleteCount) < lastEditIndex) ||
+            (deleteCount === -1) ||
-            (deleteCount === -1)) {
+            ((editIndex + deleteCount) <=
+                (lastEditIndex - ((deleteCount > 0) ? 0 : 1)))) {
             lines[lineIndex] = applyFix(lines[lineIndex], fixInfo, lineEnding);
         }
         lastLineIndex = lineIndex;
@@ -1836,8 +1837,18 @@ module.exports = {
 "use strict";
 // @ts-check
 
-var _a = __webpack_require__(/*! ../helpers */ "../helpers/helpers.js"), addErrorDetailIf = _a.addErrorDetailIf, listItemMarkerRe = _a.listItemMarkerRe, rangeFromRegExp = _a.rangeFromRegExp, unorderedListStyleFor = _a.unorderedListStyleFor;
+var _a = __webpack_require__(/*! ../helpers */ "../helpers/helpers.js"), addErrorDetailIf = _a.addErrorDetailIf, listItemMarkerRe = _a.listItemMarkerRe, unorderedListStyleFor = _a.unorderedListStyleFor;
 var flattenedLists = __webpack_require__(/*! ./cache */ "../lib/cache.js").flattenedLists;
+var expectedStyleToMarker = {
+    "dash": "-",
+    "plus": "+",
+    "asterisk": "*"
+};
+var differentItemStyle = {
+    "dash": "plus",
+    "plus": "asterisk",
+    "asterisk": "dash"
+};
 module.exports = {
     "names": ["MD004", "ul-style"],
     "description": "Unordered list style",
@@ -1855,17 +1866,28 @@ module.exports = {
                     var itemStyle = unorderedListStyleFor(item);
                     if (style === "sublist") {
                         var nesting = list.nesting;
-                        if (!nestingStyles[nesting] &&
+                        if (!nestingStyles[nesting]) {
-                            (itemStyle !== nestingStyles[nesting - 1])) {
+                            nestingStyles[nesting] =
-                            nestingStyles[nesting] = itemStyle;
+                                (itemStyle === nestingStyles[nesting - 1]) ?
-                        }
+                                    differentItemStyle[itemStyle] :
-                        else {
+                                    itemStyle;
-                            addErrorDetailIf(onError, item.lineNumber, nestingStyles[nesting], itemStyle, null, null, rangeFromRegExp(item.line, listItemMarkerRe));
                         }
+                        expectedStyle = nestingStyles[nesting];
                     }
-                    else {
+                    var range = null;
-                        addErrorDetailIf(onError, item.lineNumber, expectedStyle, itemStyle, null, null, rangeFromRegExp(item.line, listItemMarkerRe));
+                    var fixInfo = null;
+                    var match = item.line.match(listItemMarkerRe);
+                    if (match) {
+                        var column = match.index + 1;
+                        var length_1 = match[0].length;
+                        range = [column, length_1];
+                        fixInfo = {
+                            "editColumn": match[1].length + 1,
+                            "deleteCount": 1,
+                            "insertText": expectedStyleToMarker[expectedStyle]
+                        };
                     }
+                    addErrorDetailIf(onError, item.lineNumber, expectedStyle, itemStyle, null, null, range, fixInfo);
                 });
             }
         });

doc/Rules.md

@@ -142,6 +142,8 @@ Aliases: ul-style
 Parameters: style ("consistent", "asterisk", "plus", "dash", "sublist"; default
 "consistent")
 
+Fixable: Most violations can be fixed by tooling
+
 This rule is triggered when the symbols used in the document for unordered
 list items do not match the configured unordered list style:
 

helpers/helpers.js

@@ -723,8 +723,9 @@ module.exports.applyFixes = function applyFixes(input, errors) {
     const editIndex = editColumn - 1;
     if (
       (lineIndex !== lastLineIndex) ||
-      ((editIndex + deleteCount) < lastEditIndex) ||
+      (deleteCount === -1) ||
-      (deleteCount === -1)
+      ((editIndex + deleteCount) <=
+        (lastEditIndex - ((deleteCount > 0) ? 0 : 1)))
     ) {
       lines[lineIndex] = applyFix(lines[lineIndex], fixInfo, lineEnding);
     }

lib/md004.js

@@ -2,10 +2,22 @@
 
 "use strict";
 
-const { addErrorDetailIf, listItemMarkerRe,
+const { addErrorDetailIf, listItemMarkerRe, unorderedListStyleFor } =
-  rangeFromRegExp, unorderedListStyleFor } = require("../helpers");
+  require("../helpers");
 const { flattenedLists } = require("./cache");
 
+const expectedStyleToMarker = {
+  "dash": "-",
+  "plus": "+",
+  "asterisk": "*"
+};
+
+const differentItemStyle = {
+  "dash": "plus",
+  "plus": "asterisk",
+  "asterisk": "dash"
+};
+
 module.exports = {
   "names": [ "MD004", "ul-style" ],
   "description": "Unordered list style",
@@ -23,19 +35,37 @@ module.exports = {
           const itemStyle = unorderedListStyleFor(item);
           if (style === "sublist") {
             const nesting = list.nesting;
-            if (!nestingStyles[nesting] &&
+            if (!nestingStyles[nesting]) {
-              (itemStyle !== nestingStyles[nesting - 1])) {
+              nestingStyles[nesting] =
-              nestingStyles[nesting] = itemStyle;
+                (itemStyle === nestingStyles[nesting - 1]) ?
-            } else {
+                  differentItemStyle[itemStyle] :
-              addErrorDetailIf(onError, item.lineNumber,
+                  itemStyle;
-                nestingStyles[nesting], itemStyle, null, null,
-                rangeFromRegExp(item.line, listItemMarkerRe));
             }
-          } else {
+            expectedStyle = nestingStyles[nesting];
-            addErrorDetailIf(onError, item.lineNumber,
-              expectedStyle, itemStyle, null, null,
-              rangeFromRegExp(item.line, listItemMarkerRe));
           }
+          let range = null;
+          let fixInfo = null;
+          const match = item.line.match(listItemMarkerRe);
+          if (match) {
+            const column = match.index + 1;
+            const length = match[0].length;
+            range = [ column, length ];
+            fixInfo = {
+              "editColumn": match[1].length + 1,
+              "deleteCount": 1,
+              "insertText": expectedStyleToMarker[expectedStyle]
+            };
+          }
+          addErrorDetailIf(
+            onError,
+            item.lineNumber,
+            expectedStyle,
+            itemStyle,
+            null,
+            null,
+            range,
+            fixInfo
+          );
         });
       }
     });

test/detailed-results-MD001-MD010.md.fixed

@@ -7,7 +7,7 @@
 * Alpha
 * Bravo
 
-- Charlie
+* Charlie
 
 * Delta
 * Echo

test/markdownlint-test-helpers.js

@@ -459,7 +459,7 @@ test("applyFix", (t) => {
 });
 
 test("applyFixes", (t) => {
-  t.plan(29);
+  t.plan(30);
   const testCases = [
     [
       "Hello world.",
@@ -905,6 +905,27 @@ test("applyFixes", (t) => {
         }
       ],
       ""
+    ],
+    [
+      " hello world",
+      [
+        {
+          "lineNumber": 1,
+          "fixInfo": {
+            "editColumn": 1,
+            "deleteCount": 1
+          }
+        },
+        {
+          "lineNumber": 1,
+          "fixInfo": {
+            "editColumn": 2,
+            "deleteCount": 1,
+            "insertText": "H"
+          }
+        }
+      ],
+      "Hello world"
     ]
   ];
   testCases.forEach((testCase) => {

test/sublist-bullet-style.json

@@ -1,6 +0,0 @@
-{
-  "default": true,
-  "MD004": {
-    "style": "sublist"
-  }
-}

test/sublist-bullet-style.md

@@ -47,12 +47,18 @@
       - item
         * item
           * item {MD004}
-          + item
+          + item {MD004}
 
 - item
   * item
     + item
       - item
         * item
-          - item {MD004}
+          - item
-          + item
+          + item {MD004}
+
+<!-- markdownlint-configure-file {
+  "ul-style": {
+    "style": "sublist"
+  }
+} -->