feat(no-top-level-await): new rule

Author: antfu

src/index.ts

@@ -8,6 +8,7 @@ import importDedupe from './rules/import-dedupe'
 import indentUnindent from './rules/indent-unindent'
 import noImportDist from './rules/no-import-dist'
 import noImportNodeModulesByPath from './rules/no-import-node-modules-by-path'
+import noTopLevelAwait from './rules/no-top-level-await'
 import noTsExportEqual from './rules/no-ts-export-equal'
 import topLevelFunction from './rules/top-level-function'
 
@@ -26,6 +27,7 @@ const plugin = {
     'indent-unindent': indentUnindent,
     'no-import-dist': noImportDist,
     'no-import-node-modules-by-path': noImportNodeModulesByPath,
+    'no-top-level-await': noTopLevelAwait,
     'no-ts-export-equal': noTsExportEqual,
     'top-level-function': topLevelFunction,
   },

src/rules/no-top-level-await.test.ts

@@ -0,0 +1,39 @@
+import { unindent as $ } from 'eslint-vitest-rule-tester'
+import { run } from './_test'
+import rule, { RULE_NAME } from './no-top-level-await'
+
+const valids = [
+  'async function foo() { await bar() }',
+  $`
+    const a = async () => {
+      await bar()
+    }
+  `,
+]
+
+const invalids = [
+  'await foo()',
+
+  $`
+    function foo() {
+      
+    }
+    
+    await foo()
+  `,
+  $`
+    const a = {
+      foo: await bar()
+    }
+  `,
+]
+
+run({
+  name: RULE_NAME,
+  rule,
+  valid: valids,
+  invalid: invalids.map(i => ({
+    code: i,
+    errors: [{ messageId: 'NoTopLevelAwait' }],
+  })),
+})

src/rules/no-top-level-await.ts

@@ -0,0 +1,38 @@
+import type { TSESTree } from '@typescript-eslint/utils'
+import { createEslintRule } from '../utils'
+
+export const RULE_NAME = 'no-top-level-await'
+export type MessageIds = 'NoTopLevelAwait'
+export type Options = []
+
+export default createEslintRule<Options, MessageIds>({
+  name: RULE_NAME,
+  meta: {
+    type: 'problem',
+    docs: {
+      description: 'Prevent using top-level await',
+    },
+    schema: [],
+    messages: {
+      NoTopLevelAwait: 'Do not use top-level await',
+    },
+  },
+  defaultOptions: [],
+  create: (context) => {
+    return {
+      AwaitExpression: (node) => {
+        let parent: TSESTree.Node | undefined = node.parent
+        while (parent) {
+          if (parent.type === 'FunctionDeclaration' || parent.type === 'FunctionExpression' || parent.type === 'ArrowFunctionExpression') {
+            return
+          }
+          parent = parent.parent
+        }
+        context.report({
+          node,
+          messageId: 'NoTopLevelAwait',
+        })
+      },
+    }
+  },
+})