From 7e877b65b08fc24737ad688e86cfad72f5800654 Mon Sep 17 00:00:00 2001
From: Anthony Fu <anthonyfu117@hotmail.com>
Date: Thu, 5 Jan 2023 12:19:11 +0100
Subject: [PATCH] feat(findExports): support for exports destructuring (#133)

---
 src/analyze.ts       | 17 +++++++++++++++++
 src/utils.ts         |  6 +++---
 test/exports.test.ts |  6 +++++-
 3 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/src/analyze.ts b/src/analyze.ts
index 3a44a9c..cf1a83c 100644
--- a/src/analyze.ts
+++ b/src/analyze.ts
@@ -60,6 +60,7 @@ export const DYNAMIC_IMPORT_RE = /import\s*\((?<expression>(?:[^()]+|\((?:[^()]+
 
 export const EXPORT_DECAL_RE = /\bexport\s+(?<declaration>(async function|function|let|const enum|const|enum|var|class))\s+(?<name>[\w$]+)/g;
 const EXPORT_NAMED_RE = /\bexport\s+{(?<exports>[^}]+?)[\s,]*}(\s*from\s*["']\s*(?<specifier>(?<="\s*)[^"]*[^\s"](?=\s*")|(?<='\s*)[^']*[^\s'](?=\s*'))\s*["'][^\n;]*)?/g;
+const EXPORT_NAMED_DESTRUCT = /\bexport\s+(let|var|const)\s+(?:{(?<exports1>[^}]+?)[\s,]*}|\[(?<exports2>[^\]]+?)[\s,]*])\s+=/gm;
 const EXPORT_STAR_RE = /\bexport\s*(\*)(\s*as\s+(?<name>[\w$]+)\s+)?\s*(\s*from\s*["']\s*(?<specifier>(?<="\s*)[^"]*[^\s"](?=\s*")|(?<='\s*)[^']*[^\s'](?=\s*'))\s*["'][^\n;]*)?/g;
 const EXPORT_DEFAULT_RE = /\bexport\s+default\s+/g;
 const TYPE_RE = /^\s*?type\s/;
@@ -110,6 +111,21 @@ export function findExports (code: string): ESMExport[] {
       .map(name => name.replace(/^.*?\sas\s/, "").trim());
   }
 
+  const destructuredExports: NamedExport[] = matchAll(EXPORT_NAMED_DESTRUCT, code, { type: "named" });
+  for (const namedExport of destructuredExports) {
+    // @ts-expect-error groups
+    namedExport.exports = namedExport.exports1 || namedExport.exports2
+    namedExport.names = namedExport.exports
+      .replace(/^\r?\n?/, "")
+      .split(/\s*,\s*/g)
+      .filter(name => !TYPE_RE.test(name))
+      .map(name => name
+        .replace(/^.*?\s*:\s*/, "")
+        .replace(/\s*=\s*.*$/, "")
+        .trim()
+      )
+  }
+
   // Find export default
   const defaultExport: DefaultExport[] = matchAll(EXPORT_DEFAULT_RE, code, { type: "default", name: "default" });
 
@@ -121,6 +137,7 @@ export function findExports (code: string): ESMExport[] {
   const exports: ESMExport[] = [
     ...declaredExports,
     ...namedExports,
+    ...destructuredExports,
     ...defaultExport,
     ...starExports
   ];
diff --git a/src/utils.ts b/src/utils.ts
index 2c8ac0d..0dfff56 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -13,11 +13,11 @@ export function fileURLToPath (id: string): string {
 // eslint-disable-next-line no-control-regex
 const INVALID_CHAR_RE = /[\u0000-\u001F"#$&*+,/:;<=>?@[\]^`{|}\u007F]+/g;
 
-export function sanitizeURIComponent (name: string = "", replacement: string = "_"): string {
+export function sanitizeURIComponent (name = "", replacement = "_"): string {
   return name.replace(INVALID_CHAR_RE, replacement);
 }
 
-export function sanitizeFilePath (filePath: string = "") {
+export function sanitizeFilePath (filePath = "") {
   return filePath.split(/[/\\]/g).map(p => sanitizeURIComponent(p)).join("/")
     .replace(/^([A-Za-z])_\//, "$1:/");
 }
@@ -46,7 +46,7 @@ export function toDataURL (code: string): string {
   return `data:text/javascript;base64,${base64}`;
 }
 
-export function isNodeBuiltin (id: string = "") {
+export function isNodeBuiltin (id = "") {
   // node:fs/promises => fs
   id = id.replace(/^node:/, "").split("/")[0];
   return BUILTIN_MODULES.has(id);
diff --git a/test/exports.test.ts b/test/exports.test.ts
index 0182843..e4ba577 100644
--- a/test/exports.test.ts
+++ b/test/exports.test.ts
@@ -19,7 +19,11 @@ describe("findExports", () => {
     // eslint-disable-next-line no-template-curly-in-string
     "const a = `<div${JSON.stringify({ class: 42 })}>`;\nexport default true;": { type: "default", name: "default", names: ["default"] },
     "export const enum foo { a = 'xx' }": { type: "declaration", names: ["foo"] },
-    "export enum bar { a = 'xx' }": { type: "declaration", names: ["bar"] }
+    "export enum bar { a = 'xx' }": { type: "declaration", names: ["bar"] },
+    "export const { a, b } = foo": { type: "named", names: ["a", "b"] },
+    "export const [ a, b ] = foo": { type: "named", names: ["a", "b"] },
+    "export const [\na\n, b ] = foo": { type: "named", names: ["a", "b"] },
+    "export const [ a:b,\nc = 1] = foo": { type: "named", names: ["b", "c"] }
   };
 
   for (const [input, test] of Object.entries(tests)) {