Bugfix: File Cache Equality Check Incorrectly Compares Dates (#1544)

* refactors to correctly check if dates are equal

* Update attachments.js

* fixes lint error

---------

Co-authored-by: utanapishtim <[email protected]>

Author: utanapishtim

lib/mixins/attachments.js

@@ -109,7 +109,7 @@ function isEqual(a, b) {
     a.Subtype === b.Subtype &&
     a.Params.CheckSum.toString() === b.Params.CheckSum.toString() &&
     a.Params.Size === b.Params.Size &&
-    a.Params.CreationDate === b.Params.CreationDate &&
-    a.Params.ModDate === b.Params.ModDate
+    a.Params.CreationDate.getTime() === b.Params.CreationDate.getTime() &&
+    a.Params.ModDate.getTime() === b.Params.ModDate.getTime()
   );
 }

tests/unit/attachments.spec.js

@@ -192,6 +192,41 @@ describe('file', () => {
     (file2.txt) 11 0 R
 ]
 >>
+>>`
+    ]);
+  });
+
+  test('attach the same file multiple times', () => {
+    const docData = logData(document);
+
+    document.file(Buffer.from('example text'), {
+      name: 'file1.txt',
+      creationDate: date,
+      modifiedDate: date
+    });
+    document.file(Buffer.from('example text'), {
+      name: 'file1.txt',
+      creationDate: new Date(date),
+      modifiedDate: new Date(date)
+    });
+    document.end();
+
+    const numFiles = docData.filter((str) => typeof str === 'string' && str.startsWith('<<\n/Type /EmbeddedFile\n'))
+    
+    expect(numFiles.length).toEqual(1)
+    
+    expect(docData).toContainChunk([
+      `2 0 obj`,
+      `<<
+/Dests <<
+  /Names [
+]
+>>
+/EmbeddedFiles <<
+  /Names [
+    (file1.txt) 10 0 R
+]
+>>
 >>`
     ]);
   });