feat(marshal): Data({}) is pass-by-copy

Agoric · Feb 23, 2021 · 03d7b5e · 03d7b5e
1 parent d7b190f
commit 03d7b5e
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Showing 2 changed files with 9 additions and 2 deletions.
diff --git a/packages/marshal/src/marshal.js b/packages/marshal/src/marshal.js
@@ -274,6 +274,13 @@ function isPassByCopyRecord(val) {
     );
   }
 
+  if (descKeys.length === 1) {
+    if (ignorePassStyle(descKeys[0])) {
+      // the only key is the Data() marker, therefore this is pass-by-data
+      return true;
+    }
+  }
+
   for (const descKey of descKeys) {
     // we tolerate and ignore a non-enumerable PASS_STYLE symbol-named key, the Data marker
     if (ignorePassStyle(descKey)) {

diff --git a/packages/marshal/test/test-marshal.js b/packages/marshal/test/test-marshal.js
@@ -429,7 +429,7 @@ test('records', t => {
     }),
     slots: ['slot'],
   };
-  // const emptyData = { body: JSON.stringify({}), slots: [] };
+  const emptyData = { body: JSON.stringify({}), slots: [] };
 
   // For objects with Symbol-named properties
   const symEnumData = Symbol.for('symEnumData');
@@ -532,7 +532,7 @@ test('records', t => {
   // interim1: pass-by-copy without warning
   // interim2: pass-by-copy without warning
   // final: not applicable, Data() removed
-  // t.deepEqual(build('data'), emptyData); // interim 1+2
+  t.deepEqual(ser(build('data')), emptyData); // interim 1+2
 
   // Far('iface', {})
   // all cases: pass-by-ref