fix: tabWidth

* Prefer eslint's max-len.tabWidth value over indent value when setting prettier's tabWidth property. Fixes #138

* Add test for #138

* This check is redundant now that max-len.tabWidth is also passed to getTabWidth

Author: zimme

src/__tests__/utils.js

@@ -173,6 +173,26 @@ test('if fallbacks are provided, those are used if not found in eslint', () => {
   expect(prettier).toMatchObject({singleQuote: false})
 })
 
+test('eslint max-len.tabWidth value should be used for tabWidth when tabs are used', () => {
+  const {prettier} = getOptionsForFormatting({rules: {
+    indent: ['error', 'tab'],
+    'max-len': [2, {
+      tabWidth: 4,
+    }],
+  }})
+
+  expect(prettier).toMatchObject({
+    printWidth: 80,
+    tabWidth: 4,
+    parser: 'babylon',
+    singleQuote: false,
+    trailingComma: 'none',
+    bracketSpacing: true,
+    semi: true,
+    useTabs: true,
+  })
+})
+
 test('eslint config has only necessary properties', () => {
   const {eslint} = getOptionsForFormatting({
     globals: {window: false},

src/utils.js

@@ -11,7 +11,13 @@ const OPTION_GETTERS = {
     ruleValueToPrettierOption: getPrintWidth,
   },
   tabWidth: {
-    ruleValue: rules => getRuleValue(rules, 'indent'),
+    ruleValue: rules => {
+      let value = getRuleValue(rules, 'indent')
+      if (value === 'tab') {
+        value = getRuleValue(rules, 'max-len', 'tabWidth')
+      }
+      return value
+    },
     ruleValueToPrettierOption: getTabWidth,
   },
   parser: {
@@ -158,10 +164,7 @@ function getPrintWidth(eslintValue, fallbacks) {
 }
 
 function getTabWidth(eslintValue, fallbacks) {
-  // if it's set to tabs, then the tabWidth value doesn't matter
-  const prettierValue = eslintValue === 'tab' ? RULE_DISABLED : eslintValue
-
-  return makePrettierOption('tabWidth', prettierValue, fallbacks, 2)
+  return makePrettierOption('tabWidth', eslintValue, fallbacks, 2)
 }
 
 function getParser(eslintValue, fallbacks) {