Add vue/no-implicit-coercion rule

docs/rules/index.md

@@ -323,6 +323,7 @@ The following rules extend the rules provided by ESLint itself and apply them to
 | [vue/no-constant-condition](./no-constant-condition.md) | Disallow constant expressions in conditions in `<template>` |  | :warning: |
 | [vue/no-empty-pattern](./no-empty-pattern.md) | Disallow empty destructuring patterns in `<template>` |  | :warning: |
 | [vue/no-extra-parens](./no-extra-parens.md) | Disallow unnecessary parentheses in `<template>` | :wrench: | :lipstick: |
+| [vue/no-implicit-coercion](./no-implicit-coercion.md) | Disallow shorthand type conversions in `<template>` | :wrench: | :hammer: |
 | [vue/no-irregular-whitespace](./no-irregular-whitespace.md) | disallow irregular whitespace in `.vue` files |  | :warning: |
 | [vue/no-loss-of-precision](./no-loss-of-precision.md) | Disallow literal numbers that lose precision in `<template>` |  | :warning: |
 | [vue/no-restricted-syntax](./no-restricted-syntax.md) | Disallow specified syntax in `<template>` |  | :hammer: |

docs/rules/no-implicit-coercion.md

@@ -0,0 +1,32 @@
+---
+pageClass: rule-details
+sidebarDepth: 0
+title: vue/no-implicit-coercion
+description: Disallow shorthand type conversions in `<template>`
+since: v9.33.0
+---
+
+# vue/no-implicit-coercion
+
+> Disallow shorthand type conversions in `<template>`
+
+- :wrench: The `--fix` option on the [command line](https://eslint.org/docs/user-guide/command-line-interface#fixing-problems) can automatically fix some of the problems reported by this rule.
+
+This rule is the same rule as core [no-implicit-coercion] rule but it applies to the expressions in `<template>`.
+
+## :books: Further Reading
+
+- [no-implicit-coercion]
+
+[no-implicit-coercion]: https://eslint.org/docs/rules/no-implicit-coercion
+
+## :rocket: Version
+
+This rule was introduced in eslint-plugin-vue v9.33.0
+
+## :mag: Implementation
+
+- [Rule source](https://github.com/vuejs/eslint-plugin-vue/blob/master/lib/rules/no-implicit-coercion.js)
+- [Test source](https://github.com/vuejs/eslint-plugin-vue/blob/master/tests/lib/rules/no-implicit-coercion.js)
+
+<sup>Taken with ❤️ [from ESLint core](https://eslint.org/docs/latest/rules/no-implicit-coercion)</sup>

lib/index.js

@@ -126,6 +126,7 @@
     'no-export-in-script-setup': require('./rules/no-export-in-script-setup'),
     'no-expose-after-await': require('./rules/no-expose-after-await'),
     'no-extra-parens': require('./rules/no-extra-parens'),
+    'no-implicit-coercion': require('./rules/no-implicit-coercion'),
     'no-invalid-model-keys': require('./rules/no-invalid-model-keys'),
     'no-irregular-whitespace': require('./rules/no-irregular-whitespace'),
     'no-lifecycle-after-await': require('./rules/no-lifecycle-after-await'),
@@ -284,7 +285,7 @@
     vue: require('./processor')
   },
   environments: {
     // TODO Remove in the next major version
     /** @deprecated */
     'setup-compiler-macros': {
       globals: {

lib/rules/no-implicit-coercion.js

@@ -0,0 +1,12 @@
+/**
+ * @author lozinsky <https://github.com/lozinsky>
+ * See LICENSE file in root directory for full license.
+ */
+'use strict'
+
+const utils = require('../utils')
+
+// eslint-disable-next-line internal/no-invalid-meta
+module.exports = utils.wrapCoreRule('no-implicit-coercion', {
+  applyDocument: true
+})

tests/lib/rules/no-implicit-coercion.js

@@ -0,0 +1,263 @@
+/**
+ * @author lozinsky <https://github.com/lozinsky>
+ * See LICENSE file in root directory for full license.
+ */
+'use strict'
+
+const { RuleTester, ESLint } = require('../../eslint-compat')
+const semver = require('semver')
+const rule = require('../../../lib/rules/no-implicit-coercion')
+
+/**
+ * @param {string} suggestedCode
+ * @returns {string}
+ */
+function getExpectedErrorMessage(suggestedCode) {
+  return semver.gte(ESLint.version, '9.0.0')
+    ? `Unexpected implicit coercion encountered. Use \`${suggestedCode}\` instead.`
+    : `use \`${suggestedCode}\` instead.`
+}
+
+const tester = new RuleTester({
+  languageOptions: {
+    parser: require('vue-eslint-parser'),
+    ecmaVersion: 2020,
+    sourceType: 'module'
+  }
+})
+
+tester.run('no-implicit-coercion', rule, {
+  valid: [
+    `<template><div :data-foo="Boolean(foo)" /></template>`,
+    `<template><div :data-foo="foo.indexOf('.') !== -1" /></template>`,
+    {
+      filename: 'test.vue',
+      code: `<template><div :data-foo="!!foo" /></template>`,
+      options: [
+        {
+          boolean: false
+        }
+      ]
+    },
+    {
+      filename: 'test.vue',
+      code: `<template><div :data-foo="~foo.indexOf('.')" /></template>`,
+      options: [
+        {
+          boolean: false
+        }
+      ]
+    },
+    `<template><div :data-foo="Number(foo)" /></template>`,
+    ...(semver.gte(ESLint.version, '8.28.0')
+      ? [`<template><div :data-foo="foo * 1/4" /></template>`]
+      : []),
+    {
+      filename: 'test.vue',
+      code: `<template><div :data-foo="+foo" /></template>`,
+      options: [
+        {
+          number: false
+        }
+      ]
+    },
+    {
+      filename: 'test.vue',
+      code: `<template><div :data-foo="1 * foo" /></template>`,
+      options: [
+        {
+          number: false
+        }
+      ]
+    },
+    `<template><div :data-foo="String(foo)" /></template>`,
+    `<template><div :data-foo="\`\${foo}\`" /></template>`,
+    {
+      filename: 'test.vue',
+      code: `<template><div :data-foo="'' + foo" /></template>`,
+      options: [
+        {
+          string: false
+        }
+      ]
+    },
+    {
+      filename: 'test.vue',
+      code: `<template><div :data-foo="\`\` + foo" /></template>`,
+      options: [
+        {
+          string: false
+        }
+      ]
+    },
+    {
+      filename: 'test.vue',
+      code: `<template><div :data-foo="!!foo" /></template>`,
+      options: [
+        {
+          allow: ['!!']
+        }
+      ]
+    },
+    {
+      filename: 'test.vue',
+      code: `<template><div :data-foo="~foo.indexOf('.')" /></template>`,
+      options: [
+        {
+          allow: ['~']
+        }
+      ]
+    }
+  ],
+  invalid: [
+    {
+      filename: 'test.vue',
+      code: `<template><div :data-foo="!!foo" /></template>`,
+      output: `<template><div :data-foo="Boolean(foo)" /></template>`,
+      errors: [
+        {
+          message: getExpectedErrorMessage('Boolean(foo)'),
+          line: 1,
+          column: 27
+        }
+      ]
+    },
+    {
+      filename: 'test.vue',
+      code: `<template><div :data-foo="~foo.indexOf('.')" /></template>`,
+      output: null,
+      errors: [
+        {
+          message: getExpectedErrorMessage("foo.indexOf('.') !== -1"),
+          line: 1,
+          column: 27
+        }
+      ]
+    },
+    {
+      filename: 'test.vue',
+      code: `<template><div :data-foo="+foo" /></template>`,
+      output: semver.gte(ESLint.version, '9.0.0')
+        ? null
+        : `<template><div :data-foo="Number(foo)" /></template>`,
+      errors: [
+        {
+          message: getExpectedErrorMessage('Number(foo)'),
+          line: 1,
+          column: 27,
+          suggestions: semver.gte(ESLint.version, '9.0.0')
+            ? [
+                {
+                  messageId: 'useRecommendation',
+                  data: { recommendation: 'Number(foo)' },
+                  output: '<template><div :data-foo="Number(foo)" /></template>'
+                }
+              ]
+            : []
+        }
+      ]
+    },
+    {
+      filename: 'test.vue',
+      code: `<template><div :data-foo="1 * foo" /></template>`,
+      output: semver.gte(ESLint.version, '9.0.0')
+        ? null
+        : `<template><div :data-foo="Number(foo)" /></template>`,
+      errors: [
+        {
+          message: getExpectedErrorMessage('Number(foo)'),
+          line: 1,
+          column: 27,
+          suggestions: semver.gte(ESLint.version, '9.0.0')
+            ? [
+                {
+                  messageId: 'useRecommendation',
+                  data: { recommendation: 'Number(foo)' },
+                  output: '<template><div :data-foo="Number(foo)" /></template>'
+                }
+              ]
+            : []
+        }
+      ]
+    },
+    {
+      filename: 'test.vue',
+      code: `<template><div :data-foo="'' + foo" /></template>`,
+      output: semver.gte(ESLint.version, '9.0.0')
+        ? null
+        : `<template><div :data-foo="String(foo)" /></template>`,
+      errors: [
+        {
+          message: getExpectedErrorMessage('String(foo)'),
+          line: 1,
+          column: 27,
+          suggestions: semver.gte(ESLint.version, '9.0.0')
+            ? [
+                {
+                  messageId: 'useRecommendation',
+                  data: { recommendation: 'String(foo)' },
+                  output: '<template><div :data-foo="String(foo)" /></template>'
+                }
+              ]
+            : []
+        }
+      ]
+    },
+    {
+      filename: 'test.vue',
+      code: `<template><div :data-foo="\`\` + foo" /></template>`,
+      output: semver.gte(ESLint.version, '9.0.0')
+        ? null
+        : `<template><div :data-foo="String(foo)" /></template>`,
+      errors: [
+        {
+          message: getExpectedErrorMessage('String(foo)'),
+          line: 1,
+          column: 27,
+          suggestions: semver.gte(ESLint.version, '9.0.0')
+            ? [
+                {
+                  messageId: 'useRecommendation',
+                  data: { recommendation: 'String(foo)' },
+                  output: '<template><div :data-foo="String(foo)" /></template>'
+                }
+              ]
+            : []
+        }
+      ]
+    },
+    ...(semver.gte(ESLint.version, '7.24.0')
+      ? [
+          {
+            filename: 'test.vue',
+            code: `<template><div :data-foo="\`\${foo}\`" /></template>`,
+            output: semver.gte(ESLint.version, '9.0.0')
+              ? null
+              : `<template><div :data-foo="String(foo)" /></template>`,
+            options: [
+              {
+                disallowTemplateShorthand: true
+              }
+            ],
+            errors: [
+              {
+                message: getExpectedErrorMessage('String(foo)'),
+                line: 1,
+                column: 27,
+                suggestions: semver.gte(ESLint.version, '9.0.0')
+                  ? [
+                      {
+                        messageId: 'useRecommendation',
+                        data: { recommendation: 'String(foo)' },
+                        output:
+                          '<template><div :data-foo="String(foo)" /></template>'
+                      }
+                    ]
+                  : []
+              }
+            ]
+          }
+        ]
+      : [])
+  ]
+})