Extract rule: template-no-yield-to-default

README.md

@@ -254,6 +254,7 @@ 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-yield-to-default](docs/rules/template-no-yield-to-default.md)                                         | disallow yield to default block                                              |    |    |    |
 | [template-require-button-type](docs/rules/template-require-button-type.md)                                         | require button elements to have a valid type attribute                       |    | 🔧 |    |
 | [template-require-each-key](docs/rules/template-require-each-key.md)                                               | require key attribute in {{#each}} loops                                     |    | 🔧 |    |
 | [template-require-form-method](docs/rules/template-require-form-method.md)                                         | require form method attribute                                                |    | 🔧 |    |

docs/rules/template-no-yield-to-default.md

@@ -0,0 +1,51 @@
+# ember/template-no-yield-to-default
+
+<!-- end auto-generated rule header -->
+
+The `yield` keyword can be used for invoking blocks passed into a component. The `to` named argument specifies which of the blocks to yield too. Specifying `{{yield to="default"}}` is unnecessary, as that is the default behavior. Likewise, `{{has-block}}` and `{{has-block-params}}` also defaults to checking the "default" block.
+
+This rule disallow yield to named blocks with the name "default".
+
+## Examples
+
+This rule **forbids** the following:
+
+```gjs
+<template>
+  {{yield to="default"}}
+</template>
+```
+
+```gjs
+<template>
+  {{has-block "default"}}
+</template>
+```
+
+```gjs
+<template>
+  {{has-block-params "default"}}
+</template>
+```
+
+This rule **allows** the following:
+
+```gjs
+<template>
+  {{yield}}
+</template>
+```
+
+```gjs
+<template>
+  {{has-block}}
+</template>
+```
+
+```gjs
+<template>
+  {{has-block-params}}
+</template>
+```
+
+## References

lib/rules/template-no-yield-to-default.js

@@ -0,0 +1,75 @@
+const ERROR_MESSAGE = 'A block named "default" is not valid';
+
+/** @type {import('eslint').Rule.RuleModule} */
+module.exports = {
+  meta: {
+    type: 'suggestion',
+    docs: {
+      description: 'disallow yield to default block',
+      category: 'Best Practices',
+      url: 'https://github.com/ember-cli/eslint-plugin-ember/tree/master/docs/rules/template-no-yield-to-default.md',
+      templateMode: 'both',
+    },
+    fixable: null,
+    schema: [],
+    messages: {
+      invalidDefaultBlock: ERROR_MESSAGE,
+    },
+    originallyFrom: {
+      name: 'ember-template-lint',
+      rule: 'lib/rules/no-yield-to-default.js',
+      docs: 'docs/rule/no-yield-to-default.md',
+      tests: 'test/unit/rules/no-yield-to-default-test.js',
+    },
+  },
+
+  create(context) {
+    const BLOCK_HELPERS = new Set(['has-block', 'has-block-params', 'hasBlock', 'hasBlockParams']);
+
+    function checkDefaultBlockHelper(node) {
+      if (
+        node.path &&
+        node.path.type === 'GlimmerPathExpression' &&
+        BLOCK_HELPERS.has(node.path.original) &&
+        node.params &&
+        node.params.length > 0 &&
+        node.params[0].type === 'GlimmerStringLiteral' &&
+        node.params[0].value === 'default'
+      ) {
+        context.report({
+          node: node.params[0],
+          messageId: 'invalidDefaultBlock',
+        });
+      }
+    }
+
+    return {
+      GlimmerMustacheStatement(node) {
+        if (
+          node.path &&
+          node.path.type === 'GlimmerPathExpression' &&
+          node.path.original === 'yield' &&
+          node.hash &&
+          node.hash.pairs
+        ) {
+          for (const pair of node.hash.pairs) {
+            if (
+              pair.key === 'to' &&
+              pair.value.type === 'GlimmerStringLiteral' &&
+              pair.value.value === 'default'
+            ) {
+              context.report({
+                node: pair,
+                messageId: 'invalidDefaultBlock',
+              });
+            }
+          }
+        }
+        checkDefaultBlockHelper(node);
+      },
+      GlimmerSubExpression(node) {
+        checkDefaultBlockHelper(node);
+      },
+    };
+  },
+};

tests/lib/rules/template-no-yield-to-default.js

@@ -0,0 +1,120 @@
+const rule = require('../../../lib/rules/template-no-yield-to-default');
+const RuleTester = require('eslint').RuleTester;
+
+const ERROR_MESSAGE = 'A block named "default" is not valid';
+
+const validHbs = [
+  '{{yield}}',
+  '{{yield to="title"}}',
+  '{{has-block}}',
+  '{{has-block "title"}}',
+  '{{has-block-params}}',
+  '{{has-block-params "title"}}',
+  '{{hasBlock}}',
+  '{{hasBlock "title"}}',
+  '{{hasBlockParams}}',
+  '{{hasBlockParams "title"}}',
+];
+
+const invalidHbs = [
+  {
+    code: '{{yield to="default"}}',
+    output: null,
+    errors: [{ message: ERROR_MESSAGE }],
+  },
+  {
+    code: '{{has-block "default"}}',
+    output: null,
+    errors: [{ message: ERROR_MESSAGE }],
+  },
+  {
+    code: '{{has-block-params "default"}}',
+    output: null,
+    errors: [{ message: ERROR_MESSAGE }],
+  },
+  {
+    code: '{{hasBlock "default"}}',
+    output: null,
+    errors: [{ message: ERROR_MESSAGE }],
+  },
+  {
+    code: '{{hasBlockParams "default"}}',
+    output: null,
+    errors: [{ message: ERROR_MESSAGE }],
+  },
+  {
+    code: '{{if (has-block "default")}}',
+    output: null,
+    errors: [{ message: ERROR_MESSAGE }],
+  },
+  {
+    code: '{{#if (has-block "default")}}{{/if}}',
+    output: null,
+    errors: [{ message: ERROR_MESSAGE }],
+  },
+  {
+    code: '{{if (has-block-params "default")}}',
+    output: null,
+    errors: [{ message: ERROR_MESSAGE }],
+  },
+  {
+    code: '{{#if (has-block-params "default")}}{{/if}}',
+    output: null,
+    errors: [{ message: ERROR_MESSAGE }],
+  },
+  {
+    code: '{{if (hasBlock "default")}}',
+    output: null,
+    errors: [{ message: ERROR_MESSAGE }],
+  },
+  {
+    code: '{{#if (hasBlock "default")}}{{/if}}',
+    output: null,
+    errors: [{ message: ERROR_MESSAGE }],
+  },
+  {
+    code: '{{if (hasBlockParams "default")}}',
+    output: null,
+    errors: [{ message: ERROR_MESSAGE }],
+  },
+  {
+    code: '{{#if (hasBlockParams "default")}}{{/if}}',
+    output: null,
+    errors: [{ message: ERROR_MESSAGE }],
+  },
+];
+
+function wrapTemplate(entry) {
+  if (typeof entry === 'string') {
+    return `<template>${entry}</template>`;
+  }
+
+  return {
+    ...entry,
+    code: `<template>${entry.code}</template>`,
+    output: entry.output ? `<template>${entry.output}</template>` : entry.output,
+  };
+}
+
+const gjsRuleTester = new RuleTester({
+  parser: require.resolve('ember-eslint-parser'),
+  parserOptions: { ecmaVersion: 2022, sourceType: 'module' },
+});
+
+gjsRuleTester.run('template-no-yield-to-default', rule, {
+  valid: validHbs.map(wrapTemplate),
+  invalid: invalidHbs.map(wrapTemplate),
+});
+
+const hbsRuleTester = new RuleTester({
+  parser: require.resolve('ember-eslint-parser/hbs'),
+  parserOptions: {
+    ecmaVersion: 2022,
+    sourceType: 'module',
+  },
+});
+
+hbsRuleTester.run('template-no-yield-to-default', rule, {
+  valid: validHbs,
+  invalid: invalidHbs,
+});