Extract rule: template-no-whitespace-for-layout

NullVoxPopuli · NullVoxPopuli · commit 90b7967a4fdd · 2026-03-20T20:21:03.000-04:00
diff --git a/README.md b/README.md
@@ -255,6 +255,7 @@ rules in templates can be disabled with eslint directives with mustache or html
 | [template-no-obsolete-elements](docs/rules/template-no-obsolete-elements.md)                                       | disallow obsolete HTML elements                                              |    |    |    |
 | [template-no-outlet-outside-routes](docs/rules/template-no-outlet-outside-routes.md)                               | disallow {{outlet}} outside of route templates                               |    |    |    |
 | [template-no-page-title-component](docs/rules/template-no-page-title-component.md)                                 | disallow usage of ember-page-title component                                 |    |    |    |
+| [template-no-whitespace-for-layout](docs/rules/template-no-whitespace-for-layout.md)                               | disallow using whitespace for layout purposes                                |    |    |    |
 | [template-no-yield-block-params-to-else-inverse](docs/rules/template-no-yield-block-params-to-else-inverse.md)     | disallow yielding block params to else or inverse block                      |    |    |    |
 | [template-no-yield-only](docs/rules/template-no-yield-only.md)                                                     | disallow components that only yield                                          |    |    |    |
 | [template-no-yield-to-default](docs/rules/template-no-yield-to-default.md)                                         | disallow yield to default block                                              |    |    |    |
diff --git a/docs/rules/template-no-whitespace-for-layout.md b/docs/rules/template-no-whitespace-for-layout.md
@@ -0,0 +1,56 @@
+# ember/template-no-whitespace-for-layout
+
+<!-- end auto-generated rule header -->
+
+Disallow using multiple consecutive spaces for layout purposes in templates. CSS should be used for spacing and layout instead.
+
+## Rule Details
+
+This rule discourages the use of multiple consecutive spaces (2 or more) for layout purposes in templates. CSS should be used for spacing and layout instead.
+
+## Examples
+
+Examples of **incorrect** code for this rule:
+
+```gjs
+<template>
+  <div>Hello   World</div>
+</template>
+```
+
+```gjs
+<template>
+  <div>Text    with    spaces</div>
+</template>
+```
+
+```gjs
+<template>
+  <div>Multiple     spaces</div>
+</template>
+```
+
+Examples of **correct** code for this rule:
+
+```gjs
+<template>
+  <div>Hello World</div>
+</template>
+```
+
+```gjs
+<template>
+  <div class="spaced-layout">Text with proper spacing</div>
+</template>
+```
+
+## Migration
+
+To fix issues caused by using whitespace for layout, the following are recommended:
+
+- use the appropriate HTML markup to contain the information
+- use CSS to add padding or margins to the semantic HTML markup
+
+## References
+
+- [eslint-plugin-ember template-no-whitespace-for-layout](https://github.com/ember-cli/eslint-plugin-ember/blob/master/docs/rules/template-no-whitespace-for-layout.md)
diff --git a/lib/rules/template-no-whitespace-for-layout.js b/lib/rules/template-no-whitespace-for-layout.js
@@ -0,0 +1,51 @@
+/** @type {import('eslint').Rule.RuleModule} */
+module.exports = {
+  meta: {
+    type: 'suggestion',
+    docs: {
+      description: 'disallow using whitespace for layout purposes',
+      category: 'Best Practices',
+      url: 'https://github.com/ember-cli/eslint-plugin-ember/tree/master/docs/rules/template-no-whitespace-for-layout.md',
+      templateMode: 'both',
+    },
+    schema: [],
+    messages: {
+      noWhitespaceForLayout:
+        'Unexpected use of whitespace for layout. Use CSS for spacing instead of multiple spaces.',
+    },
+    originallyFrom: {
+      name: 'ember-template-lint',
+      rule: 'lib/rules/no-whitespace-for-layout.js',
+      docs: 'docs/rule/no-whitespace-for-layout.md',
+      tests: 'test/unit/rules/no-whitespace-for-layout-test.js',
+    },
+  },
+
+  create(context) {
+    const sourceCode = context.getSourceCode();
+
+    return {
+      GlimmerTextNode(node) {
+        const text = sourceCode.getText(node);
+        if (!text) {
+          return;
+        }
+
+        const lines = text.split('\n');
+        for (const line of lines) {
+          // Ignore whitespace at the start and end of the line
+          const trimmed = line.trim();
+
+          // Check for two consecutive ` ` or `&nbsp;` in a row
+          if (/(( )|(&nbsp;))(( )|(&nbsp;))/.test(trimmed)) {
+            context.report({
+              node,
+              messageId: 'noWhitespaceForLayout',
+            });
+            return;
+          }
+        }
+      },
+    };
+  },
+};
diff --git a/tests/lib/rules/template-no-whitespace-for-layout.js b/tests/lib/rules/template-no-whitespace-for-layout.js
@@ -0,0 +1,136 @@
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const rule = require('../../../lib/rules/template-no-whitespace-for-layout');
+const RuleTester = require('eslint').RuleTester;
+
+const ruleTester = new RuleTester({
+  parser: require.resolve('ember-eslint-parser'),
+  parserOptions: { ecmaVersion: 2022, sourceType: 'module' },
+});
+
+ruleTester.run('template-no-whitespace-for-layout', rule, {
+  valid: [
+    '<template><div>Hello World</div></template>',
+    '<template><div>Text</div></template>',
+
+    '<template>Start to finish</template>',
+    '<template>Start&nbsp;to&nbsp;finish</template>',
+    '<template>Start<br>to<br>finish</template>',
+    `<template><div>
+  example
+</div></template>`,
+    `<template><div
+  foo="bar"
+  baz="qux"
+>
+  example
+</div></template>`,
+  ],
+  invalid: [
+    {
+      code: '<template><div>Hello   World</div></template>',
+      output: null,
+      errors: [{ messageId: 'noWhitespaceForLayout' }],
+    },
+    {
+      code: '<template><div>Text    with    spaces</div></template>',
+      output: null,
+      errors: [{ messageId: 'noWhitespaceForLayout' }],
+    },
+    {
+      code: '<template><div>Multiple     spaces</div></template>',
+      output: null,
+      errors: [{ messageId: 'noWhitespaceForLayout' }],
+    },
+
+    {
+      code: '<template>START  FINISH</template>',
+      output: null,
+      errors: [{ messageId: 'noWhitespaceForLayout' }],
+    },
+    {
+      code: '<template>START&nbsp;&nbsp;FINISH</template>',
+      output: null,
+      errors: [{ messageId: 'noWhitespaceForLayout' }],
+    },
+    {
+      code: '<template>START&nbsp; FINISH</template>',
+      output: null,
+      errors: [{ messageId: 'noWhitespaceForLayout' }],
+    },
+    {
+      code: '<template>START &nbsp;FINISH</template>',
+      output: null,
+      errors: [{ messageId: 'noWhitespaceForLayout' }],
+    },
+  ],
+});
+
+const hbsRuleTester = new RuleTester({
+  parser: require.resolve('ember-eslint-parser/hbs'),
+  parserOptions: {
+    ecmaVersion: 2022,
+    sourceType: 'module',
+  },
+});
+
+hbsRuleTester.run('template-no-whitespace-for-layout', rule, {
+  valid: [
+    'Start to finish',
+    'Start&nbsp;to&nbsp;finish',
+    'Start<br>to<br>finish',
+    `<div>
+  example
+</div>`,
+    `<div
+  foo="bar"
+  baz="qux"
+>
+  example
+</div>`,
+  ],
+  invalid: [
+    {
+      code: 'START  FINISH',
+      output: null,
+      errors: [
+        {
+          message:
+            'Unexpected use of whitespace for layout. Use CSS for spacing instead of multiple spaces.',
+        },
+      ],
+    },
+    {
+      code: 'START&nbsp;&nbsp;FINISH',
+      output: null,
+      errors: [
+        {
+          message:
+            'Unexpected use of whitespace for layout. Use CSS for spacing instead of multiple spaces.',
+        },
+      ],
+    },
+    {
+      code: 'START&nbsp; FINISH',
+      output: null,
+      errors: [
+        {
+          message:
+            'Unexpected use of whitespace for layout. Use CSS for spacing instead of multiple spaces.',
+        },
+      ],
+    },
+    {
+      code: 'START &nbsp;FINISH',
+      output: null,
+      errors: [
+        {
+          message:
+            'Unexpected use of whitespace for layout. Use CSS for spacing instead of multiple spaces.',
+        },
+      ],
+    },
+  ],
+});
