Update: Support .prettierrc config files (fixes #46) (#55)

README.md

@@ -54,8 +54,7 @@ Then, in your `.eslintrc.json`:
 ## Options
 
 * The first option:
-
-  - Objects are passed directly to Prettier as [options](https://github.com/prettier/prettier#api). Example:
+  - Objects are passed directly to Prettier as [options](https://github.com/prettier/prettier#options). Example:
 
     ```json
     "prettier/prettier": ["error", {"singleQuote": true, "parser": "flow"}]
@@ -78,6 +77,7 @@ Then, in your `.eslintrc.json`:
       "parser": "flow"
     }]
     ```
+  NB: This option will merge and override any config set with `.prettierrc` files (for Prettier < 1.7.0, [config files are ignored](https://github.com/prettier/eslint-plugin-prettier/issues/46))
 
 * The second option:
 

eslint-plugin-prettier.js

@@ -306,11 +306,6 @@ module.exports = {
         ]
       },
       create(context) {
-        const prettierOptions =
-          context.options[0] === 'fb'
-            ? FB_PRETTIER_OPTIONS
-            : context.options[0];
-
         const pragma = context.options[1]
           ? context.options[1].slice(1) // Remove leading @
           : null;
@@ -342,12 +337,31 @@ module.exports = {
           }
         }
 
+        if (prettier) {
+          prettier.clearConfigCache();
+        }
+
         return {
           Program() {
             if (!prettier) {
               // Prettier is expensive to load, so only load it if needed.
               prettier = require('prettier');
             }
+
+            const eslintPrettierOptions =
+              context.options[0] === 'fb'
+                ? FB_PRETTIER_OPTIONS
+                : context.options[0];
+            const prettierRcOptions =
+              prettier.resolveConfig && prettier.resolveConfig.sync
+                ? prettier.resolveConfig.sync(context.getFilename())
+                : null;
+            const prettierOptions = Object.assign(
+              {},
+              prettierRcOptions,
+              eslintPrettierOptions
+            );
+
             const prettierSource = prettier.format(source, prettierOptions);
             if (source !== prettierSource) {
               const differences = generateDifferences(source, prettierSource);

test/prettier.js

@@ -40,7 +40,21 @@ ruleTester.run('prettier', rule, {
     // Facebook style with pragma.
     { code: `/** @format */\n('');\n`, options: ['fb', '@format'] },
     // Shebang with pragma.
-    { code: `#!/bin/node\n/** @format */\n"";\n`, options: [null, '@format'] }
+    { code: `#!/bin/node\n/** @format */\n"";\n`, options: [null, '@format'] },
+    // Single quote from .prettierrc.
+    { code: `'';\n`, filename: getPrettierRcJsFilename('single-quote') },
+    // Override .prettierrc from object option.
+    {
+      code: `var foo = {bar: 0};\n`,
+      filename: getPrettierRcJsFilename('bracket-spacing'),
+      options: [{ bracketSpacing: false }]
+    },
+    // Override .prettierrc from facebook option.
+    {
+      code: `('');\n`,
+      filename: getPrettierRcJsFilename('double-quote'),
+      options: ['fb']
+    }
   ],
   invalid: [
     '01',
@@ -120,3 +134,12 @@ function loadInvalidFixture(name) {
   };
   return item;
 }
+
+/**
+ * Builds a dummy javascript file path to trick prettier into resolving a specific .prettierrc file.
+ * @param {string} name - Prettierrc fixture basename.
+ * @returns {string} A javascript filename relative to the .prettierrc config.
+ */
+function getPrettierRcJsFilename(name) {
+  return path.resolve(__dirname, `./prettierrc/${name}/dummy.js`);
+}

test/prettierrc/bracket-spacing/.prettierrc

@@ -0,0 +1,3 @@
+{
+  "bracketSpacing": true
+}

test/prettierrc/double-quote/.prettierrc

@@ -0,0 +1,3 @@
+{
+  "singleQuote": false
+}

test/prettierrc/single-quote/.prettierrc

@@ -0,0 +1,3 @@
+{
+  "singleQuote": true
+}

yarn.lock

@@ -556,9 +556,9 @@ isarray@^1.0.0, isarray@~1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/isarray/-/isarray-1.0.0.tgz#bb935d48582cba168c06834957a54a3e07124f11"
 
-jest-docblock@^20.0.1:
-  version "20.0.3"
-  resolved "https://registry.yarnpkg.com/jest-docblock/-/jest-docblock-20.0.3.tgz#17bea984342cc33d83c50fbe1545ea0efaa44712"
+jest-docblock@^21.0.0:
+  version "21.1.0"
+  resolved "https://registry.yarnpkg.com/jest-docblock/-/jest-docblock-21.1.0.tgz#43154be2441fb91403e36bb35cb791a5017cea81"
 
 js-tokens@^3.0.0:
   version "3.0.1"
@@ -763,8 +763,8 @@ prelude-ls@~1.1.2:
   resolved "https://registry.yarnpkg.com/prelude-ls/-/prelude-ls-1.1.2.tgz#21932a549f5e52ffd9a827f570e04be62a97da54"
 
 prettier@^1.6.1:
-  version "1.6.1"
-  resolved "https://registry.yarnpkg.com/prettier/-/prettier-1.6.1.tgz#850f411a3116226193e32ea5acfc21c0f9a76d7d"
+  version "1.7.0"
+  resolved "https://registry.yarnpkg.com/prettier/-/prettier-1.7.0.tgz#47481588f41f7c90f63938feb202ac82554e7150"
 
 process-nextick-args@~1.0.6:
   version "1.0.7"