support reexports via require spreads

README.md

@@ -82,11 +82,13 @@ EXPORTS_LITERAL_COMPUTED_ASSIGN: EXPORTS_IDENTIFIER COMMENT_SPACE `[` COMMENT_SP
 
 EXPORTS_LITERAL_PROP: (IDENTIFIER (COMMENT_SPACE `:` COMMENT_SPACE IDENTIFIER)?) | (IDENTIFIER_STRING COMMENT_SPACE `:` COMMENT_SPACE IDENTIFIER)
 
+EXPORTS_SPREAD: `...` COMMENT_SPACE (IDENTIFIER | REQUIRE)
+
 EXPORTS_MEMBER: EXPORTS_DOT_ASSIGN | EXPORTS_LITERAL_COMPUTED_ASSIGN
 
 EXPORTS_DEFINE: `Object` COMMENT_SPACE `.` COMMENT_SPACE `defineProperty COMMENT_SPACE `(` EXPORTS_IDENTIFIER COMMENT_SPACE `,` COMMENT_SPACE IDENTIFIER_STRING
 
-EXPORTS_LITERAL: MODULE_EXPORTS COMMENT_SPACE `=` COMMENT_SPACE `{` COMMENT_SPACE (EXPORTS_LITERAL_PROP COMMENT_SPACE `,` COMMENT_SPACE)+ `}`
+EXPORTS_LITERAL: MODULE_EXPORTS COMMENT_SPACE `=` COMMENT_SPACE `{` COMMENT_SPACE (EXPORTS_LITERAL_PROP | EXPORTS_SPREAD) COMMENT_SPACE `,` COMMENT_SPACE)+ `}`
 
 REQUIRE: `require` COMMENT_SPACE `(` COMMENT_SPACE STRING_LITERAL COMMENT_SPACE `)`
 
@@ -112,7 +114,9 @@ EXPORT_STAR_LIB: `Object.keys(` IDENTIFIER$1 `).forEach(function (` IDENTIFIER$2
 ```
 
 * The returned export names are the matched `IDENTIFIER` and `IDENTIFIER_STRING` slots for all `EXPORTS_MEMBER`, `EXPORTS_DEFINE` and `EXPORTS_LITERAL` matches.
-* The reexport specifiers are taken to be the `STRING_LITERAL` slot of the last `MODULE_EXPORTS_ASSIGN` as well as all _top-level_ `EXPORT_STAR` `REQUIRE` matches and `EXPORTS_ASSIGN` matches whose `IDENTIFIER` also matches the first `IDENTIFIER` in `EXPORT_STAR_LIB`.
+* The reexport specifiers are taken to be the the combination of:
+  1. The `REQUIRE` matches of the last matched of either `MODULE_EXPORTS_ASSIGN` or `EXPORTS_LITERAL`.
+  2. All _top-level_ `EXPORT_STAR` `REQUIRE` matches and `EXPORTS_ASSIGN` matches whose `IDENTIFIER` also matches the first `IDENTIFIER` in `EXPORT_STAR_LIB`.
 
 ### Parsing Examples
 
@@ -164,16 +168,18 @@ Simple object definitions are supported:
 module.exports = {
   a,
   'b': b,
-  c: c
+  c: c,
+  ...d
 };
 ```
 
-Object properties that are not identifiers or string expressions will bail out of the object detection:
+Object properties that are not identifiers or string expressions will bail out of the object detection, while spreads are ignored:
 
 ```js
 // DETECTS EXPORTS: a, b
 module.exports = {
   a,
+  ...d,
   b: require('c'),
   c: "not detected since require('c') above bails the object detection"
 }
@@ -192,7 +198,18 @@ module.exports = require('a');
 if (false) module.exports = require('c');
 ```
 
-This is to avoid overclassification in Webpack bundles with externals which include `module.exports = require('external')` in their source for every external dependency.
+This is to avoid over-classification in Webpack bundles with externals which include `module.exports = require('external')` in their source for every external dependency.
+
+In exports object assignment, any spread of `require()` are detected as multiple separate reexports:
+
+```js
+// DETECTS REEXPORTS: a, b
+module.exports = require('ignored');
+module.exports = {
+  ...require('a'),
+  ...require('b')
+};
+```
 
 #### Transpiler Re-exports
 

lexer.js

@@ -10,7 +10,7 @@ let openTokenDepth,
   nextBraceIsClass,
   starExportMap,
   lastStarExportSpecifier,
-  lastExportsAssignSpecifier,
+  lastExportsAssignReexports,
   _exports,
   reexports;
 
@@ -26,7 +26,7 @@ function resetState () {
   nextBraceIsClass = false;
   starExportMap = Object.create(null);
   lastStarExportSpecifier = null;
-  lastExportsAssignSpecifier = null;
+  lastExportsAssignReexports = new Set();
 
   _exports = new Set();
   reexports = new Set();
@@ -49,8 +49,8 @@ module.exports = function parseCJS (source, name = '@') {
     e.loc = pos;
     throw e;
   }
-  if (lastExportsAssignSpecifier)
-    reexports.add(lastExportsAssignSpecifier);
+  for (const reexport of lastExportsAssignReexports)
+    reexports.add(reexport);
   const result = { exports: [..._exports], reexports: [...reexports] };
   resetState();
   return result;
@@ -677,6 +677,8 @@ function tryParseExportsDotAssign (assign) {
     // module.exports =
     case 61/*=*/: {
       if (assign) {
+        if (lastExportsAssignReexports.size)
+          lastExportsAssignReexports = new Set();
         pos++;
         ch = commentWhitespace();
         // { ... }
@@ -696,9 +698,9 @@ function tryParseExportsDotAssign (assign) {
 
 function tryParseRequire (requireType) {
   // require('...')
+  const revertPos = pos;
   if (source.startsWith('equire', pos + 1)) {
     pos += 7;
-    const revertPos = pos - 1;
     let ch = commentWhitespace();
     if (ch === 40/*(*/) {
       pos++;
@@ -711,7 +713,7 @@ function tryParseRequire (requireType) {
         if (ch === 41/*)*/) {
           switch (requireType) {
             case ExportAssign:
-              lastExportsAssignSpecifier = source.slice(reexportStart, reexportEnd);
+              lastExportsAssignReexports.add(source.slice(reexportStart, reexportEnd));
               return true;
             case ExportStar:
               reexports.add(source.slice(reexportStart, reexportEnd));
@@ -729,7 +731,7 @@ function tryParseRequire (requireType) {
         if (ch === 41/*)*/) {
           switch (requireType) {
             case ExportAssign:
-              lastExportsAssignSpecifier = source.slice(reexportStart, reexportEnd);
+              lastExportsAssignReexports.add(source.slice(reexportStart, reexportEnd));
               return true;
             case ExportStar:
               reexports.add(source.slice(reexportStart, reexportEnd));
@@ -766,6 +768,17 @@ function tryParseLiteralExports () {
       }
       addExport(source.slice(startPos, endPos));
     }
+    else if (ch === 46/*.*/ && source.startsWith('..', pos + 1)) {
+      pos += 3;
+      if (source.charCodeAt(pos) === 114/*r*/ && tryParseRequire(ExportAssign)) {
+        pos++;
+      }
+      else if (!identifier()) {
+        pos = revertPos;
+        return;
+      }
+      ch = commentWhitespace();
+    }
     else if (ch === 39/*'*/ || ch === 34/*"*/) {
       const startPos = ++pos;
       if (identifier() && source.charCodeAt(pos) === ch) {

test/_unit.js

@@ -234,6 +234,25 @@ suite('Lexer', () => {
     assert.equal(exports.length, 0);
   });
 
+  test('module exports reexport spread', () => {
+    const { exports, reexports } = parse(`
+      module.exports = {
+        ...a,
+        ...b,
+        ...require('dep1'),
+        c: d,
+        ...require('dep2'),
+        name
+      };
+    `);
+    assert.equal(exports.length, 2);
+    assert.equal(exports[0], 'c');
+    assert.equal(exports[1], 'name');
+    assert.equal(reexports.length, 2);
+    assert.equal(reexports[0], 'dep1');
+    assert.equal(reexports[1], 'dep2');
+  });
+
   test('Regexp case', () => {
     parse(`
       class Number {