diff --git a/README.md b/README.md
index 9366d74..15c6907 100644
--- a/README.md
+++ b/README.md
@@ -95,7 +95,8 @@ Contributions are welcome!
 ## References
 
  - https://github.com/apache/parquet-format
- - https://github.com/dask/fastparquet
+ - https://github.com/apache/parquet-testing
  - https://github.com/apache/thrift
+ - https://github.com/dask/fastparquet
  - https://github.com/google/snappy
  - https://github.com/zhipeng-jia/snappyjs
diff --git a/src/toJson.js b/src/toJson.js
index bf81685..11c1295 100644
--- a/src/toJson.js
+++ b/src/toJson.js
@@ -14,6 +14,7 @@ export function toJson(obj) {
     /** @type {Record<string, unknown>} */
     const newObj = {}
     for (const key of Object.keys(obj)) {
+      if (obj[key] === undefined) continue
       newObj[key] = toJson(obj[key])
     }
     return newObj
diff --git a/test/files/README.md b/test/files/README.md
new file mode 100644
index 0000000..beb0bcb
--- /dev/null
+++ b/test/files/README.md
@@ -0,0 +1,7 @@
+# Test Files License
+
+This directory contains binary test files from [apache/parquet-testing](https://github.com/apache/parquet-testing), under the [Apache 2.0 license](https://www.apache.org/licenses/LICENSE-2.0).
+
+Copyright 2004 The Apache Software Foundation (http://www.apache.org/).
+
+
diff --git a/test/files/byte_array_decimal.json b/test/files/byte_array_decimal.json
new file mode 100644
index 0000000..7ce1ae6
--- /dev/null
+++ b/test/files/byte_array_decimal.json
@@ -0,0 +1,26 @@
+[
+  [ 10000 ],
+  [ 20000 ],
+  [ 30000 ],
+  [ 40000 ],
+  [ 50000 ],
+  [ 60000 ],
+  [ 70000 ],
+  [ 80000 ],
+  [ 90000 ],
+  [ 100000 ],
+  [ 110000 ],
+  [ 120000 ],
+  [ 130000 ],
+  [ 140000 ],
+  [ 150000 ],
+  [ 160000 ],
+  [ 170000 ],
+  [ 180000 ],
+  [ 190000 ],
+  [ 200000 ],
+  [ 210000 ],
+  [ 220000 ],
+  [ 230000 ],
+  [ 240000 ]
+]
diff --git a/test/files/byte_array_decimal.metadata.json b/test/files/byte_array_decimal.metadata.json
new file mode 100644
index 0000000..4abe4d0
--- /dev/null
+++ b/test/files/byte_array_decimal.metadata.json
@@ -0,0 +1,43 @@
+{
+  "version": 1,
+  "created_by": "HVR 5.3.0/9 (linux_glibc2.5-x64-64bit)",
+  "metadata_length": 119,
+  "num_rows": 24,
+  "row_groups": [
+    {
+      "columns": [
+        {
+          "file_offset": 4,
+          "meta_data": {
+            "codec": "UNCOMPRESSED",
+            "data_page_offset": 4,
+            "encodings": [],
+            "num_values": 24,
+            "path_in_schema": [ "value" ],
+            "total_compressed_size": 168,
+            "total_uncompressed_size": 168,
+            "type": 6
+          }
+        }
+      ],
+      "num_rows": 24,
+      "total_byte_size": 168
+    }
+  ],
+  "schema": [
+    {
+      "name": "schema",
+      "num_children": 1,
+      "repetition_type": "REQUIRED"
+    },
+    {
+      "converted_type": "DECIMAL",
+      "field_id": 6,
+      "name": "value",
+      "precision": 4,
+      "repetition_type": "OPTIONAL",
+      "scale": 2,
+      "type": 6
+    }
+  ]
+}
diff --git a/test/files/byte_array_decimal.parquet b/test/files/byte_array_decimal.parquet
new file mode 100644
index 0000000..798cb2a
Binary files /dev/null and b/test/files/byte_array_decimal.parquet differ
diff --git a/test/files/rowgroups.metadata.json b/test/files/rowgroups.metadata.json
index 7588211..1560d55 100644
--- a/test/files/rowgroups.metadata.json
+++ b/test/files/rowgroups.metadata.json
@@ -77,10 +77,12 @@
   ],
   "key_value_metadata": [
     {
-      "key": "pandas"
+      "key": "pandas",
+      "value": "{\"index_columns\": [{\"kind\": \"range\", \"name\": null, \"start\": 0, \"stop\": 15, \"step\": 1}], \"column_indexes\": [{\"name\": null, \"field_name\": null, \"pandas_type\": \"unicode\", \"numpy_type\": \"object\", \"metadata\": {\"encoding\": \"UTF-8\"}}], \"columns\": [{\"name\": \"numbers\", \"field_name\": \"numbers\", \"pandas_type\": \"int64\", \"numpy_type\": \"int64\", \"metadata\": null}], \"creator\": {\"library\": \"pyarrow\", \"version\": \"14.0.2\"}, \"pandas_version\": \"2.1.4\"}"
     },
     {
-      "key": "ARROW:schema"
+      "key": "ARROW:schema",
+      "value": "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"
     }
   ]
 }
diff --git a/test/metadata.test.js b/test/metadata.test.js
index 54c1e2a..6c0eb7b 100644
--- a/test/metadata.test.js
+++ b/test/metadata.test.js
@@ -13,7 +13,7 @@ describe('parquetMetadata', () => {
       const result = parquetMetadata(arrayBuffer)
       const base = file.replace('.parquet', '')
       const expected = fileToJson(`test/files/${base}.metadata.json`)
-      expect(toJson(result)).containSubset(expected)
+      expect(toJson(result)).toEqual(expected)
     }
   })
 
@@ -54,7 +54,7 @@ describe('parquetMetadataAsync', () => {
       const result = await parquetMetadataAsync(asyncBuffer)
       const base = file.replace('.parquet', '')
       const expected = fileToJson(`test/files/${base}.metadata.json`)
-      expect(toJson(result)).containSubset(expected)
+      expect(toJson(result)).toEqual(expected)
     }
   })