1// Extract destructured names from dynamic imports like:
2//   const {foo, bar} = await import('./path.mjs')
3//   const {foo: aliased} = isDevPc ? await import('./path.mjs') : fallback
4
5// Given an AwaitExpression or ImportExpression node, walk up to find the VariableDeclarator
6// and extract destructured property names from its id pattern
7import type { AcornNode } from './libAcornF.mts'
8
9export const extractDynamicImportNames = (importExprNode: AcornNode, ancestors: AcornNode[]) => {
10  if (!ancestors?.length) return null
11  
12  // Walk up ancestors to find VariableDeclarator
13  // Pattern: VariableDeclarator -> AwaitExpression -> ImportExpression
14  // Or with ternary: VariableDeclarator -> ConditionalExpression -> AwaitExpression -> ImportExpression
15  let varDeclarator: AcornNode | null = null
16  for (const ancestor of ancestors) {
17    if (ancestor.type === 'VariableDeclarator') {
18      varDeclarator = ancestor
19      break
20    }
21  }
22  
23  if (!varDeclarator?.id) return null
24  
25  if (varDeclarator.id.type === 'ObjectPattern') {
26    const names: string[] = []
27    for (const prop of varDeclarator.id.properties) {
28      if (prop.type === 'Property' && prop.key?.type === 'Identifier') {
29        // Use the key name (the exported name), not the local alias
30        names.push(prop.key.name)
31      }
32    }
33    return names.length > 0 ? names : null
34  }
35  
36  // Single identifier: const foo = await import('./path.mjs')
37  // This imports the module namespace, similar to: import * as foo from './path.mjs'
38  // Return null to trigger namespace expansion
39  if (varDeclarator.id.type === 'Identifier') {
40    return null // Will fall back to 'dynamic' or namespace expansion
41  }
42  
43  return null
44}
45