Add style/prettier.json (fixes #592).

doc/Prettier.md

@@ -1,8 +1,12 @@
 # Using markdownlint with Prettier
 
-[`Prettier`](https://prettier.io) is a popular code formatter. For the most part,
-it works seamlessly with `markdownlint`. Special situations are documented
-below.
+[`Prettier`](https://prettier.io) is a popular code formatter.
+For the most part, Prettier works seamlessly with `markdownlint`.
+
+You can extend the `markdownlint/style/prettier.json` style to disable all
+markdownlint rules that overlap with Prettier.
+
+Special situations when not extending `prettier.json` are documented below.
 
 ## List item indentation
 

package.json

@@ -9,6 +9,7 @@
     "./helpers": "./helpers/helpers.js",
     "./style/all": "./style/all.json",
     "./style/cirosantilli": "./style/cirosantilli.json",
+    "./style/prettier": "./style/prettier.json",
     "./style/relaxed": "./style/relaxed.json"
   },
   "types": "./lib/markdownlint.d.ts",

style/prettier.json

@@ -0,0 +1,25 @@
+{
+  "comment": "Disables rules that may conflict with Prettier",
+  "blanks-around-fences": false,
+  "blanks-around-headings": false,
+  "blanks-around-lists": false,
+  "code-fence-style": false,
+  "emphasis-style": false,
+  "heading-start-left": false,
+  "hr-style": false,
+  "line-length": false,
+  "list-indent": false,
+  "list-marker-space": false,
+  "no-blanks-blockquote": false,
+  "no-hard-tabs": false,
+  "no-missing-space-atx": false,
+  "no-missing-space-closed-atx": false,
+  "no-multiple-blanks": false,
+  "no-multiple-space-atx": false,
+  "no-multiple-space-blockquote": false,
+  "no-multiple-space-closed-atx": false,
+  "no-trailing-spaces": false,
+  "ol-prefix": false,
+  "strong-style": false,
+  "ul-indent": false
+}

test/markdownlint-test.js

@@ -431,7 +431,7 @@ test("enableTagMixedCase", (t) => new Promise((resolve) => {
 }));
 
 test("styleFiles", (t) => new Promise((resolve) => {
-  t.plan(7);
+  t.plan(9);
   fs.readdir("./style", function readdir(err, files) {
     t.falsy(err);
     for (const file of files) {