Add avoidEscape option to vue/html-quotes rule

docs/rules/html-quotes.md

@@ -43,13 +43,19 @@ Default is set to `double`.
 
 ```json
 {
-  "vue/html-quotes": ["error", "double" | "single"]
+  "vue/html-quotes": [ "error", "double" | "single", { "avoidEscape": false } ]
 }
 ```
 
+String option:
+
 - `"double"` (default) ... requires double quotes.
 - `"single"` ... requires single quotes.
 
+Object option:
+
+- `avoidEscape` ... If `true`, allows strings to use single-quotes or double-quotes so long as the string contains a quote that would have to be escaped otherwise.
+
 ### `"single"`
 
 <eslint-code-block fix :rules="{'vue/html-quotes': ['error', 'single']}">
@@ -67,6 +73,23 @@ Default is set to `double`.
 
 </eslint-code-block>
 
+### `"double", { "avoidEscape": true }`
+
+<eslint-code-block fix :rules="{'vue/html-quotes': ['error', 'double', { avoidEscape: true }]}">
+
+```vue
+<template>
+  <!-- ✓ GOOD -->
+  <img title='a string containing "double" quotes'>
+
+  <!-- ✗ BAD -->
+  <img title='foo'>
+  <img title=bar>
+</template>
+```
+
+</eslint-code-block>
+
 ## :books: Further reading
 
 - [Style guide - Quoted attribute values](https://vuejs.org/v2/style-guide/#Quoted-attribute-values-strongly-recommended)

lib/rules/html-quotes.js

@@ -25,17 +25,25 @@ module.exports = {
     },
     fixable: 'code',
     schema: [
-      { enum: ['double', 'single'] }
+      { enum: ['double', 'single'] },
+      {
+        type: 'object',
+        properties: {
+          avoidEscape: {
+            type: 'boolean'
+          }
+        },
+        additionalProperties: false
+      }
     ]
   },
 
   create (context) {
     const sourceCode = context.getSourceCode()
     const double = context.options[0] !== 'single'
+    const avoidEscape = context.options[1] && context.options[1].avoidEscape === true
     const quoteChar = double ? '"' : "'"
     const quoteName = double ? 'double quotes' : 'single quotes'
-    const quotePattern = double ? /"/g : /'/g
-    const quoteEscaped = double ? '"' : '''
     let hasInvalidEOF
 
     return utils.defineTemplateBodyVisitor(context, {
@@ -48,14 +56,35 @@ module.exports = {
         const firstChar = text[0]
 
         if (firstChar !== quoteChar) {
+          const quoted = (firstChar === "'" || firstChar === '"')
+          if (avoidEscape && quoted) {
+            const contentText = text.slice(1, -1)
+            if (contentText.includes(quoteChar)) {
+              return
+            }
+          }
+
           context.report({
             node: node.value,
             loc: node.value.loc,
             message: 'Expected to be enclosed by {{kind}}.',
             data: { kind: quoteName },
             fix (fixer) {
-              const contentText = (firstChar === "'" || firstChar === '"') ? text.slice(1, -1) : text
-              const replacement = quoteChar + contentText.replace(quotePattern, quoteEscaped) + quoteChar
+              const contentText = quoted ? text.slice(1, -1) : text
+
+              const fixToDouble = avoidEscape && !quoted && contentText.includes(quoteChar)
+                ? (
+                  double
+                    ? contentText.includes("'")
+                    : !contentText.includes('"')
+                )
+                : double
+
+              const quotePattern = fixToDouble ? /"/g : /'/g
+              const quoteEscaped = fixToDouble ? '"' : '''
+              const fixQuoteChar = fixToDouble ? '"' : "'"
+
+              const replacement = fixQuoteChar + contentText.replace(quotePattern, quoteEscaped) + fixQuoteChar
               return fixer.replaceText(node.value, replacement)
             }
           })

tests/lib/rules/html-quotes.js

@@ -55,6 +55,17 @@ tester.run('html-quotes', rule, {
       code: "<template><div :class='foo'></div></template>",
       options: ['single']
     },
+    // avoidEscape
+    {
+      filename: 'test.vue',
+      code: "<template><div attr='foo\"bar'></div></template>",
+      options: ['double', { avoidEscape: true }]
+    },
+    {
+      filename: 'test.vue',
+      code: "<template><div attr=\"foo'bar\"></div></template>",
+      options: ['single', { avoidEscape: true }]
+    },
 
     // Invalid EOF
     {
@@ -166,6 +177,49 @@ tester.run('html-quotes', rule, {
       output: "<template><div :class='foo+&apos;bar&apos;'></div></template>",
       options: ['single'],
       errors: ['Expected to be enclosed by single quotes.']
+    },
+    // avoidEscape
+    {
+      filename: 'test.vue',
+      code: "<template><div attr='foo'></div></template>",
+      output: '<template><div attr="foo"></div></template>',
+      options: ['double', { avoidEscape: true }],
+      errors: ['Expected to be enclosed by double quotes.']
+    },
+    {
+      filename: 'test.vue',
+      code: '<template><div attr="bar"></div></template>',
+      output: "<template><div attr='bar'></div></template>",
+      options: ['single', { avoidEscape: true }],
+      errors: ['Expected to be enclosed by single quotes.']
+    },
+    {
+      filename: 'test.vue',
+      code: '<template><div attr=foo"bar></div></template>',
+      output: '<template><div attr=\'foo"bar\'></div></template>',
+      options: ['double', { avoidEscape: true }],
+      errors: ['Expected to be enclosed by double quotes.']
+    },
+    {
+      filename: 'test.vue',
+      code: '<template><div attr=foo\'bar></div></template>',
+      output: "<template><div attr=\"foo'bar\"></div></template>",
+      options: ['single', { avoidEscape: true }],
+      errors: ['Expected to be enclosed by single quotes.']
+    },
+    {
+      filename: 'test.vue',
+      code: '<template><div attr=foo"bar\'baz></div></template>',
+      output: '<template><div attr="foo&quot;bar\'baz"></div></template>',
+      options: ['double', { avoidEscape: true }],
+      errors: ['Expected to be enclosed by double quotes.']
+    },
+    {
+      filename: 'test.vue',
+      code: '<template><div attr=foo"bar\'baz></div></template>',
+      output: '<template><div attr=\'foo"bar&apos;baz\'></div></template>',
+      options: ['single', { avoidEscape: true }],
+      errors: ['Expected to be enclosed by single quotes.']
     }
   ]
 })