test/python/utils/test_json_writer.py

   1 # SPDX-License-Identifier: GPL-3.0-or-later
   2 #
   3 # This file is part of Nominatim. (https://nominatim.org)
   4 #
   5 # Copyright (C) 2024 by the Nominatim developer community.
   6 # For a full list of authors see the git log.
   7 """
   8 Tests for the streaming JSON writer.
   9 """
  10 import json
  11
  12 import pytest
  13
  14 from nominatim_core.utils.json_writer import JsonWriter
  15
  16 @pytest.mark.parametrize("inval,outstr", [(None, 'null'),
  17                                           (True, 'true'), (False, 'false'),
  18                                           (23, '23'), (0, '0'), (-1.3, '-1.3'),
  19                                           ('g\nä', '"g\\nä"'), ('"', '"\\\""'),
  20                                           ({}, '{}'), ([], '[]')])
  21 def test_simple_value(inval, outstr):
  22     writer = JsonWriter()
  23     writer.value(inval)
  24
  25     assert writer() == outstr
  26     json.loads(writer())
  27
  28
  29 def test_empty_array():
  30     writer = JsonWriter().start_array().end_array()
  31
  32     assert writer() == '[]'
  33     json.loads(writer())
  34
  35
  36 def test_array_with_single_value():
  37     writer = JsonWriter().start_array().value(None).end_array()
  38
  39     assert writer() == '[null]'
  40     json.loads(writer())
  41
  42
  43 @pytest.mark.parametrize("invals,outstr", [((1, ), '[1]'),
  44                                            (('a', 'b'), '["a","b"]')])
  45 def test_array_with_data(invals, outstr):
  46     writer = JsonWriter()
  47
  48     writer.start_array()
  49     for ival in invals:
  50         writer.value(ival).next()
  51     writer.end_array()
  52
  53     assert writer() == outstr
  54     json.loads(writer())
  55
  56
  57 def test_empty_object():
  58     writer = JsonWriter().start_object().end_object()
  59
  60     assert writer() == '{}'
  61     json.loads(writer())
  62
  63
  64 def test_object_single_entry():
  65     writer = JsonWriter()\
  66                 .start_object()\
  67                     .key('something')\
  68                     .value(5)\
  69                 .end_object()
  70
  71     assert writer() == '{"something":5}'
  72     json.loads(writer())
  73
  74 def test_object_many_values():
  75     writer = JsonWriter()\
  76                 .start_object()\
  77                     .keyval('foo', None)\
  78                     .keyval('bar', {})\
  79                     .keyval('baz', 'b\taz')\
  80                 .end_object()
  81
  82     assert writer() == '{"foo":null,"bar":{},"baz":"b\\taz"}'
  83     json.loads(writer())
  84
  85 def test_object_many_values_without_none():
  86     writer = JsonWriter()\
  87                 .start_object()\
  88                     .keyval_not_none('foo', 0)\
  89                     .keyval_not_none('bar', None)\
  90                     .keyval_not_none('baz', '')\
  91                     .keyval_not_none('eve', False,
  92                                      transform = lambda v: 'yes' if v else 'no')\
  93                 .end_object()
  94
  95     assert writer() == '{"foo":0,"baz":"","eve":"no"}'
  96     json.loads(writer())
  97
  98
  99 def test_raw_output():
 100     writer = JsonWriter()\
 101                 .start_array()\
 102                     .raw('{ "nicely": "formatted here" }').next()\
 103                     .value(1)\
 104                 .end_array()
 105
 106     assert writer() == '[{ "nicely": "formatted here" },1]'