MAINT: Improve test coverage (#2796)

tests/test_writer.py

@@ -2188,6 +2188,10 @@ def test_replace_object():
     reader._replace_object(reader.pages[0].indirect_reference, reader.pages[0])
     pg = PageObject.create_blank_page(writer, 1000, 1000)
     reader._replace_object(reader.pages[0].indirect_reference, pg)
+    pg = PageObject.create_blank_page(None, 1000, 1000)
+    pg[NameObject("/Contents")] = writer.pages[0]["/Contents"]
+    writer._add_object(pg)
+    writer.add_page(pg)
 
 
 def test_mime_jupyter():
@@ -2300,3 +2304,9 @@ def test_matrix_entry_in_field_annots():
         auto_regenerate=False,
     )
     assert "/Matrix" in writer.pages[0]["/Annots"][5].get_object()["/AP"]["/N"]
+
+
+def test_set_need_appearances_writer():
+    """Minimal test for coverage"""
+    writer = PdfWriter()
+    writer.set_need_appearances_writer()

tests/test_xmp.py

@@ -7,7 +7,7 @@
 
 import pypdf.generic
 import pypdf.xmp
-from pypdf import PdfReader
+from pypdf import PdfReader, PdfWriter
 from pypdf.errors import PdfReadError
 
 from . import get_data_from_url
@@ -42,6 +42,35 @@ def test_read_xmp_metadata_samples(src):
     }
 
 
+def test_writer_xmp_metadata_samples():
+    writer = PdfWriter(SAMPLE_ROOT / "020-xmp/output_with_metadata_pymupdf.pdf")
+    xmp = writer.xmp_metadata
+    assert xmp
+    assert xmp.dc_contributor == []
+    assert xmp.dc_creator == ["John Doe"]
+    assert xmp.dc_source == "Martin Thoma"  # attribute node
+    assert xmp.dc_description == {"x-default": "This is a text"}
+    assert xmp.dc_date == [datetime(1990, 4, 28, 0, 0)]
+    assert xmp.dc_title == {"x-default": "Sample PDF with XMP Metadata"}
+    assert xmp.custom_properties == {
+        "Style": "FooBarStyle",
+        "other": "worlds",
+        "⏰": "time",
+    }
+    co = pypdf.generic.ContentStream(None, None)
+    co.set_data(
+        xmp.stream.get_data().replace(
+            b'dc:source="Martin Thoma"', b'dc:source="Pubpub-Zz"'
+        )
+    )
+    writer.xmp_metadata = pypdf.xmp.XmpInformation(co)
+    b = BytesIO()
+    writer.write(b)
+    reader = PdfReader(b)
+    xmp2 = reader.xmp_metadata
+    assert xmp2.dc_source == "Pubpub-Zz"
+
+
 @pytest.mark.parametrize(
     ("src", "has_xmp"),
     [