Fix float("inf") and float("nan") JSON serialization breaking reports (#1964)

Author: clementsicard

elementary/monitor/data_monitoring/report/data_monitoring_report.py

@@ -21,6 +21,7 @@
 from elementary.monitor.data_monitoring.schema import FiltersSchema
 from elementary.tracking.anonymous_tracking import AnonymousTracking
 from elementary.tracking.tracking_interface import Tracking
+from elementary.utils import json_utils
 from elementary.utils.log import get_logger
 
 logger = get_logger(__name__)
@@ -74,7 +75,7 @@ def generate_report(
         with open(template_html_path, "r", encoding="utf-8") as template_html_file:
             template_html_code = template_html_file.read()
 
-        dumped_output_data = json.dumps(output_data)
+        dumped_output_data = json.dumps(json_utils.inf_and_nan_to_str(output_data))
         encoded_output_data = base64.b64encode(dumped_output_data.encode("utf-8"))
         compiled_output_html = (
             f"<script>"

elementary/utils/json_utils.py

@@ -1,5 +1,7 @@
 import json
-from typing import List, Optional, Union
+from typing import Any, List, Optional, Union
+
+import numpy as np
 
 
 def try_load_json(value: Optional[Union[str, dict, list]]):
@@ -76,3 +78,20 @@ def append_prefix_if_missing(string: str, prefix: str) -> str:
     if string.startswith(prefix):
         return string
     return f"{prefix}{string}"
+
+
+def inf_and_nan_to_str(obj) -> Any:
+    """Replaces occurrences of float("nan") for float("infinity") in the given dict object."""
+    if isinstance(obj, float):
+        if np.isinf(obj):
+            return "Infinity" if obj > 0 else "-Infinity"
+        elif np.isnan(obj):
+            return "NaN"
+        else:
+            return obj
+    elif isinstance(obj, dict):
+        return {k: inf_and_nan_to_str(v) for k, v in obj.items()}
+    elif isinstance(obj, list):
+        return [inf_and_nan_to_str(i) for i in obj]
+    else:
+        return obj

tests/unit/utils/test_dicts.py

@@ -1,5 +1,6 @@
 import json
 
+from elementary.utils import json_utils
 from elementary.utils.dicts import flatten_dict_by_key, merge_dicts_attribute
 
 
@@ -29,3 +30,12 @@ def test_merge_dicts_attribute():
     assert sorted(
         merge_dicts_attribute(dicts=[dict_1, dict_2, dict_3], attribute_key="attr")
     ) == sorted([1, 2, 2, 3])
+
+
+def test_replace_inf_and_nan():
+    data = {"values": [1.0, float("inf"), float("-inf"), float("nan")]}
+    data = dict(a=1.0, b=float("inf"), c=float("-inf"), d=float("nan"))
+
+    processed_data = json_utils.inf_and_nan_to_str(data)
+    json_str = json.dumps(processed_data, sort_keys=True)
+    assert json_str == '{"a": 1.0, "b": "Infinity", "c": "-Infinity", "d": "NaN"}'