fix: partially support re-export

relate #121

Author: sxzz

src/fake-js.ts

@@ -279,6 +279,7 @@ export function createFakeJsPlugin({
     const { program } = file
 
     program.body = patchTsNamespace(program.body)
+    program.body = patchReExport(program.body)
 
     program.body = program.body
       .map((node) => {
@@ -725,6 +726,9 @@ function patchImportExport(
   }
 }
 
+/**
+ * Handle `__export` call
+ */
 function patchTsNamespace(nodes: t.Statement[]) {
   const removed = new Set<t.Node>()
 
@@ -784,6 +788,90 @@ function patchTsNamespace(nodes: t.Statement[]) {
   }
 }
 
+/**
+ * Handle `__reExport` call
+ */
+function patchReExport(nodes: t.Statement[]) {
+  const exportsNames = new Map<string, string>()
+
+  for (const [i, node] of nodes.entries()) {
+    if (
+      node.type === 'ImportDeclaration' &&
+      node.specifiers.length === 1 &&
+      node.specifiers[0].type === 'ImportSpecifier' &&
+      node.specifiers[0].local.type === 'Identifier' &&
+      node.specifiers[0].local.name.endsWith('_exports')
+    ) {
+      // record: import { t as a_exports } from "..."
+      exportsNames.set(
+        node.specifiers[0].local.name,
+        node.specifiers[0].local.name,
+      )
+    } else if (
+      node.type === 'ExpressionStatement' &&
+      node.expression.type === 'CallExpression' &&
+      node.expression.callee.type === 'Identifier' &&
+      node.expression.callee.name === '__reExport'
+    ) {
+      // record: __reExport(a_exports, import_lib)
+
+      const args = node.expression.arguments
+      exportsNames.set(
+        (args[0] as t.Identifier).name,
+        (args[1] as t.Identifier).name,
+      )
+    } else if (
+      node.type === 'VariableDeclaration' &&
+      node.declarations.length === 1 &&
+      node.declarations[0].init?.type === 'MemberExpression' &&
+      node.declarations[0].init.object.type === 'Identifier' &&
+      exportsNames.has(node.declarations[0].init.object.name)
+    ) {
+      // var B = a_exports.A
+      // to
+      // type B = [mapping].A
+      // TODO how to support value import? currently only type import is supported
+
+      nodes[i] = {
+        type: 'TSTypeAliasDeclaration',
+        id: {
+          type: 'Identifier',
+          name: (node.declarations[0].id as t.Identifier).name,
+        },
+        typeAnnotation: {
+          type: 'TSTypeReference',
+          typeName: {
+            type: 'TSQualifiedName',
+            left: {
+              type: 'Identifier',
+              name: exportsNames.get(node.declarations[0].init.object.name)!,
+            },
+            right: {
+              type: 'Identifier',
+              name: (node.declarations[0].init.property as t.Identifier).name,
+            },
+          },
+        },
+      }
+    } else if (
+      node.type === 'ExportNamedDeclaration' &&
+      node.specifiers.length === 1 &&
+      node.specifiers[0].type === 'ExportSpecifier' &&
+      node.specifiers[0].local.type === 'Identifier' &&
+      exportsNames.has(node.specifiers[0].local.name)
+    ) {
+      // export { a_exports as t }
+      // to
+      // export { [mapping] as t }
+      node.specifiers[0].local.name = exportsNames.get(
+        node.specifiers[0].local.name,
+      )!
+    }
+  }
+
+  return nodes
+}
+
 // fix:
 // - import type { ... } from '...'
 // - import { type ... } from '...'

tests/__snapshots__/index.test.ts.snap

@@ -222,6 +222,20 @@ import { Input2, input2 } from "./input2-CzdQ8V-e.js";
 export { Input2, input2 };"
 `;
 
+exports[`external namespace 1`] = `
+"// index.d.ts
+import { t as mod_d_exports } from "./mod-3KblRJ7v.js";
+type A = mod_d_exports.A;
+export { A };
+// mod-3KblRJ7v.d.ts
+import * as import_lib from "lib";
+//#endregion
+export { import_lib as t };
+// mod.d.ts
+import "./mod-3KblRJ7v.js";
+export * from "lib";"
+`;
+
 exports[`input alias 1`] = `
 "// input2-CcmD5Ns-.d.ts
 //#region shared.d.ts

tests/fixtures/external-namespace/index.ts

@@ -0,0 +1 @@
+export { A } from './mod'

tests/fixtures/external-namespace/mod.ts

@@ -0,0 +1 @@
+export * from 'lib'

tests/index.test.ts

@@ -502,3 +502,12 @@ test('advancedChunks', async () => {
   expect(snapshot).toMatchSnapshot()
   expect(chunks).toHaveLength(2)
 })
+
+test('external namespace', async () => {
+  const root = path.resolve(dirname, 'fixtures/external-namespace')
+  const { snapshot } = await rolldownBuild(
+    [path.resolve(root, 'index.ts'), path.resolve(root, 'mod.ts')],
+    [dts({ emitDtsOnly: true })],
+  )
+  expect(snapshot).toMatchSnapshot()
+})