From e0a7037b65dfe3b0e69e1484ef9b1e80547901e8 Mon Sep 17 00:00:00 2001
From: Anthony Fu <github@antfu.me>
Date: Wed, 27 Nov 2024 22:15:24 +0800
Subject: [PATCH] feat: new command `no-x-above`

---
 src/commands/index.ts           |  3 ++
 src/commands/no-x-above.md      | 30 ++++++++++++++++++
 src/commands/no-x-above.test.ts | 44 ++++++++++++++++++++++++++
 src/commands/no-x-above.ts      | 56 +++++++++++++++++++++++++++++++++
 4 files changed, 133 insertions(+)
 create mode 100644 src/commands/no-x-above.md
 create mode 100644 src/commands/no-x-above.test.ts
 create mode 100644 src/commands/no-x-above.ts

diff --git a/src/commands/index.ts b/src/commands/index.ts
index e0b6614..4f5c2b0 100644
--- a/src/commands/index.ts
+++ b/src/commands/index.ts
@@ -4,6 +4,7 @@ import { keepSorted } from './keep-sorted'
 import { keepUnique } from './keep-unique'
 import { noShorthand } from './no-shorthand'
 import { noType } from './no-type'
+import { noXAbove } from './no-x-above'
 import { regex101 } from './regex101'
 import { toArrow } from './to-arrow'
 import { toDestructuring } from './to-destructuring'
@@ -24,6 +25,7 @@ export {
   keepUnique,
   noShorthand,
   noType,
+  noXAbove,
   regex101,
   toArrow,
   toDestructuring,
@@ -45,6 +47,7 @@ export const builtinCommands = [
   keepUnique,
   noShorthand,
   noType,
+  noXAbove,
   regex101,
   toArrow,
   toDestructuring,
diff --git a/src/commands/no-x-above.md b/src/commands/no-x-above.md
new file mode 100644
index 0000000..e0c9eef
--- /dev/null
+++ b/src/commands/no-x-above.md
@@ -0,0 +1,30 @@
+# `no-x-above`
+
+Disallow certain syntaxes above or below the comment, with in the current block.
+
+## Triggers
+
+- `// @no-await-above` - Disallow `await` above the comment.
+- `// @no-await-below` - Disallow `await` below the comment.
+
+## Examples
+
+```js
+const foo = syncOp()
+const bar = await asyncOp() // <-- this is not allowed
+// @no-await-above
+const baz = await asyncOp() // <-- this is ok
+```
+
+The effect will only affect the current scope, for example:
+
+```js
+console.log(await foo()) // <-- this is not checked, as it's not in the function scope where the comment is
+
+async function foo() {
+  const bar = syncOp()
+  const baz = await asyncOp() // <-- this is not allowed
+  // @no-await-above
+  const qux = await asyncOp() // <-- this is ok
+}
+```
diff --git a/src/commands/no-x-above.test.ts b/src/commands/no-x-above.test.ts
new file mode 100644
index 0000000..555a7b2
--- /dev/null
+++ b/src/commands/no-x-above.test.ts
@@ -0,0 +1,44 @@
+import { $, run } from './_test-utils'
+import { noXAbove as command } from './no-x-above'
+
+run(
+  command,
+  // {
+  //   code: $`
+  //     /// no-await-below
+  //     const obj = await foo()
+  //   `,
+  //   errors: ['command-error'],
+  // },
+  // $`
+  //   const obj = await foo()
+  //   /// no-await-below
+  //   const obj = foo()
+  // `,
+  // {
+  //   code: $`
+  //     const obj = await foo()
+  //     /// no-await-above
+  //     const obj = foo()
+  //   `,
+  //   errors: ['command-fix'],
+  // },
+  // // Don't count outside of scope
+  // $`
+  //   await foo()
+  //   async function foo() {
+  //     /// no-await-above
+  //     const obj = await Promise.all([])
+  //   }
+  // `,
+  // Don't count inside
+  $`
+    async function foo() {
+      /// no-await-below
+      console.log('foo')
+      const bar = async () => {
+        const obj = await Promise.all([])
+      }
+    }
+  `,
+)
diff --git a/src/commands/no-x-above.ts b/src/commands/no-x-above.ts
new file mode 100644
index 0000000..c1824cc
--- /dev/null
+++ b/src/commands/no-x-above.ts
@@ -0,0 +1,56 @@
+import type { Command } from '../types'
+
+const types = [
+  'await',
+
+  // TODO: implement
+  // 'statements',
+  // 'functions',
+] as const
+
+export const noXAbove: Command = {
+  name: 'no-x-above',
+  match: new RegExp(`^\\s*[/:@]\\s*no-(${types.join('|')})-(above|below)$`),
+  action(ctx) {
+    const type = ctx.matches[1] as (typeof types)[number]
+    const direction = ctx.matches[2] as 'above' | 'below'
+
+    const node = ctx.findNodeBelow(() => true)
+    const parent = node?.parent
+    if (!parent)
+      return ctx.reportError('No parent node found')
+
+    if (parent.type !== 'Program' && parent.type !== 'BlockStatement')
+      return ctx.reportError('Parent node is not a block')
+
+    const children = parent.body
+
+    const targetNodes = direction === 'above'
+      ? children.filter(c => c.range[1] <= ctx.comment.range[0])
+      : children.filter(c => c.range[0] >= ctx.comment.range[1])
+
+    if (!targetNodes.length)
+      return
+
+    switch (type) {
+      case 'await':
+        for (const target of targetNodes) {
+          ctx.traverse(target, (path, { SKIP }) => {
+            if (path.node.type === 'FunctionDeclaration' || path.node.type === 'FunctionExpression' || path.node.type === 'ArrowFunctionExpression') {
+              return SKIP
+            }
+            if (path.node.type === 'AwaitExpression') {
+              ctx.report({
+                node: path.node,
+                message: 'Disallowed await expression',
+              })
+            }
+          })
+        }
+        return
+      default:
+        return ctx.reportError(`Unknown type: ${type}`)
+    }
+    // console.log({ targetRange: targetNodes })
+  },
+}