Add autofix to selector-list-comma-newline-after (#3815)

docs/user-guide/rules.md

@@ -308,7 +308,7 @@ Here are all the rules within stylelint, grouped first [by category](../../VISIO
 
 #### Selector list
 
--   [`selector-list-comma-newline-after`](../../lib/rules/selector-list-comma-newline-after/README.md): Require a newline or disallow whitespace after the commas of selector lists.
+-   [`selector-list-comma-newline-after`](../../lib/rules/selector-list-comma-newline-after/README.md): Require a newline or disallow whitespace after the commas of selector lists (Autofixable).
 -   [`selector-list-comma-newline-before`](../../lib/rules/selector-list-comma-newline-before/README.md): Require a newline or disallow whitespace before the commas of selector lists (Autofixable).
 -   [`selector-list-comma-space-after`](../../lib/rules/selector-list-comma-space-after/README.md): Require a single space or disallow whitespace after the commas of selector lists (Autofixable).
 -   [`selector-list-comma-space-before`](../../lib/rules/selector-list-comma-space-before/README.md): Require a single space or disallow whitespace before the commas of selector lists (Autofixable).

lib/rules/selector-list-comma-newline-after/README.md

@@ -16,6 +16,8 @@ a, /* comment */
 b { color: pink; }
 ```
 
+The `--fix` option on the [command line](../../../docs/user-guide/cli.md#autofixing-errors) can automatically fix all of the problems reported by this rule.
+
 ## Options
 
 `string`: `"always"|"always-multi-line"|"never-multi-line"`

lib/rules/selector-list-comma-newline-after/__tests__/index.js

@@ -6,6 +6,7 @@ const { messages, ruleName } = rule;
 testRule(rule, {
   ruleName,
   config: ["always"],
+  fix: true,
 
   accept: [
     {
@@ -130,61 +131,78 @@ testRule(rule, {
   reject: [
     {
       code: "a,b {}",
+      fixed: "a,\nb {}",
       message: messages.expectedAfter(),
       line: 1,
       column: 2
     },
     {
       code: "a, b {}",
+      fixed: "a,\n b {}",
       message: messages.expectedAfter(),
       line: 1,
       column: 2
     },
     {
       code: "a,  b {}",
+      fixed: "a,\n  b {}",
       message: messages.expectedAfter(),
       line: 1,
       column: 2
     },
     {
       code: "a,\tb {}",
+      fixed: "a,\n\tb {}",
       message: messages.expectedAfter(),
       line: 1,
       column: 2
     },
     {
       code: "a,\nb,c {}",
+      fixed: "a,\nb,\nc {}",
       message: messages.expectedAfter(),
       line: 2,
       column: 2
     },
     {
       code: "a,\r\nb,c {}",
+      fixed: "a,\r\nb,\r\nc {}",
       description: "CRLF",
       message: messages.expectedAfter(),
       line: 2,
       column: 2
     },
     {
       code: "a, /* comment */ b {}",
+      fixed: "a, /* comment */\n b {}",
       description: "with post-comma comment without newline after",
       message: messages.expectedAfter(),
       line: 1,
       column: 2
     },
     {
       code: "a, /* comment\n       commentline2 */b {}",
+      fixed: "a, /* comment\n       commentline2 */\nb {}",
       description: "with post-comma multi-line comment without newline after",
       message: messages.expectedAfter(),
       line: 1,
       column: 2
+    },
+    {
+      code: "a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z {\n}",
+      fixed:
+        "a,\nb,\nc,\nd,\ne,\nf,\ng,\nh,\ni,\nj,\nk,\nl,\nm,\nn,\no,\np,\nq,\nr,\ns,\nt,\nu,\nv,\nw,\nx,\ny,\nz {\n}",
+      message: messages.expectedAfter(),
+      line: 1,
+      column: 2
     }
   ]
 });
 
 testRule(rule, {
   ruleName,
   config: ["always-multi-line"],
+  fix: true,
 
   accept: [
     {
@@ -216,18 +234,21 @@ testRule(rule, {
   reject: [
     {
       code: "a,\nb, c {}",
+      fixed: "a,\nb,\n c {}",
       message: messages.expectedAfterMultiLine(),
       line: 2,
       column: 2
     },
     {
       code: "a,\nb, c {\n}",
+      fixed: "a,\nb,\n c {\n}",
       message: messages.expectedAfterMultiLine(),
       line: 2,
       column: 2
     },
     {
       code: "a,\r\nb, c {\r\n}",
+      fixed: "a,\r\nb,\r\n c {\r\n}",
       description: "CRLF",
       message: messages.expectedAfterMultiLine(),
       line: 2,
@@ -239,6 +260,7 @@ testRule(rule, {
 testRule(rule, {
   ruleName,
   config: ["never-multi-line"],
+  fix: true,
 
   accept: [
     {
@@ -265,19 +287,44 @@ testRule(rule, {
   reject: [
     {
       code: "a,\nb ,c {}",
+      fixed: "a,b ,c {}",
       message: messages.rejectedAfterMultiLine(),
       line: 1,
       column: 2
     },
     {
       code: "a,\r\nb ,c {}",
+      fixed: "a,b ,c {}",
       description: "CRLF",
       message: messages.rejectedAfterMultiLine(),
       line: 1,
       column: 2
     },
     {
       code: "a,\nb ,c {\n}",
+      fixed: "a,b ,c {\n}",
+      message: messages.rejectedAfterMultiLine(),
+      line: 1,
+      column: 2
+    },
+    {
+      code: "a,\n\n   \t b ,c {\n}",
+      fixed: "a,b ,c {\n}",
+      message: messages.rejectedAfterMultiLine(),
+      line: 1,
+      column: 2
+    },
+    {
+      code: "a,\n/*comment*/\nb ,\nc {\n}",
+      fixed: "a,\n/*comment*/b ,c {\n}",
+      message: messages.rejectedAfterMultiLine(),
+      line: 1,
+      column: 2
+    },
+    {
+      code:
+        "a,\nb,\nc,\nd,\ne,\nf,\ng,\nh,\ni,\nj,\nk,\nl,\nm,\nn,\no,\np,\nq,\nr,\ns,\nt,\nu,\nv,\nw,\nx,\ny,\nz {\n}",
+      fixed: "a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z {\n}",
       message: messages.rejectedAfterMultiLine(),
       line: 1,
       column: 2
@@ -290,6 +337,7 @@ testRule(rule, {
   config: ["always"],
   skipBasicChecks: true,
   syntax: "scss",
+  fix: true,
 
   accept: [
     {
@@ -322,6 +370,7 @@ testRule(rule, {
   config: ["always"],
   skipBasicChecks: true,
   syntax: "less",
+  fix: true,
 
   accept: [
     {

lib/rules/selector-list-comma-newline-after/index.js

@@ -17,7 +17,7 @@ const messages = ruleMessages(ruleName, {
     'Unexpected whitespace after "," in a multi-line list'
 });
 
-const rule = function(expectation) {
+const rule = function(expectation, options, context) {
   const checker = whitespaceChecker("newline", expectation, messages);
 
   return (root, result) => {
@@ -42,6 +42,8 @@ const rule = function(expectation) {
         ? rule.raws.selector.raw
         : rule.selector;
 
+      const fixIndices = [];
+
       styleSearch(
         {
           source: selector,
@@ -68,17 +70,49 @@ const rule = function(expectation) {
           checker.afterOneOnly({
             source: selector,
             index: indextoCheckAfter,
-            err: m =>
+            err: m => {
+              if (context.fix) {
+                fixIndices.push(indextoCheckAfter + 1);
+
+                return;
+              }
+
               report({
                 message: m,
                 node: rule,
                 index: match.startIndex,
                 result,
                 ruleName
-              })
+              });
+            }
           });
         }
       );
+
+      if (fixIndices.length) {
+        let fixedSelector = selector;
+
+        fixIndices
+          .sort((a, b) => b - a)
+          .forEach(index => {
+            const beforeSelector = fixedSelector.slice(0, index);
+            let afterSelector = fixedSelector.slice(index);
+
+            if (expectation.indexOf("always") === 0) {
+              afterSelector = context.newline + afterSelector;
+            } else if (expectation.indexOf("never-multi-line") === 0) {
+              afterSelector = afterSelector.replace(/^\s*/, "");
+            }
+
+            fixedSelector = beforeSelector + afterSelector;
+          });
+
+        if (rule.raws.selector) {
+          rule.raws.selector.raw = fixedSelector;
+        } else {
+          rule.selector = fixedSelector;
+        }
+      }
     });
   };
 };