Readability and typing improvements.

Author: Anteru

sjson/__init__.py

@@ -169,7 +169,7 @@ def _skip_characters_and_whitespace(stream: _InputStream, num_char_to_skip: int)
 _WHITESPACE_SET = frozenset([b' ', b'\t', b'\n', b'\r'])
 
 
-def _is_whitespace(char):
+def _is_whitespace(char: bytes | None):
     return char in _WHITESPACE_SET
 
 
@@ -230,11 +230,11 @@ def _skip_whitespace(stream: _InputStream):
 _IDENTIFIER_SET = frozenset(string.ascii_letters + string.digits + '_')
 
 
-def _is_identifier(obj):
+def _is_identifier(obj: bytes):
     return chr(obj[0]) in _IDENTIFIER_SET
 
 
-def _decode_escaped_character(char):
+def _decode_escaped_character(char: bytes):
     match char:
         case b'b':
             return b'\b'
@@ -289,6 +289,11 @@ def _decode_string(stream: _InputStream, allow_identifier=False):
 
     while True:
         next_char = stream.peek()
+
+        # peek() cannot return None here as we don't allow peeking beyond the
+        # end of the file
+        assert next_char is not None
+
         if parse_as_identifier and not _is_identifier(next_char):
             break
 
@@ -547,8 +552,8 @@ def _escape_string(obj: str, quote=True) -> typing.Generator[str, None, None]:
 def _encode(
     obj: _SUPPORTED_ENCODE_TYPE,
     separators: tuple[str, str, str] = (', ', '\n', ' = '),
-    indent=0,
-    level=0,
+    indent: str = '',
+    level: int = 0,
 ):
     match obj:
         case None:
@@ -581,7 +586,8 @@ def _encode_key(k: str):
 
 
 def _encode_list(
-    obj: typing.Sequence, separators: tuple[str, str, str], indent: str, level: int
+    obj: typing.Sequence, separators: tuple[str, str, str],
+    indent: str, level: int
 ):
     yield '['
     first = True
@@ -595,10 +601,12 @@ def _encode_list(
 
 
 def _encode_dict(
-    obj: typing.Mapping, separators: tuple[str, str, str], indent: str, level: int
+    obj: typing.Mapping, separators: tuple[str, str, str],
+    indent: str, level: int
 ):
     if level > 0:
-        yield '{\n'
+        yield '{'
+        yield separators[1]
     first = True
     for key, value in obj.items():
         if first:
@@ -609,7 +617,7 @@ def _encode_dict(
         yield from _encode_key(key)
         yield separators[2]
         yield from _encode(value, separators, indent, level + 1)
-    yield '\n'
+    yield separators[1]
     yield _indent(level - 1, indent)
     if level > 0:
         yield '}'

sjson/test/test_sjson.py

@@ -160,28 +160,33 @@ def testBugDecodeFailure1():
 
 def testReportErrorOnIncompleteArray1():
     s = "test = [1, 2, "
-    with pytest.raises(Exception):
+    with pytest.raises(sjson.ParseException):
         sjson.loads(s)
 
 
 def testReportErrorOnIncompleteArray2():
     s = "test = ["
-    with pytest.raises(Exception):
+    with pytest.raises(sjson.ParseException):
         sjson.loads(s)
 
 
 def testReportOnIncompleteMap1():
     s = "test = "
-    with pytest.raises(Exception):
+    with pytest.raises(sjson.ParseException):
         sjson.loads(s)
 
 
 def testReportOnIncompleteMap2():
     s = "test "
-    with pytest.raises(Exception):
+    with pytest.raises(sjson.ParseException):
         sjson.loads(s)
 
 
+def testReportOnKeyOnly():
+    with pytest.raises(sjson.ParseException):
+        sjson.loads('foo')
+
+
 def testBugDecodeFailsForFloats():
     s = "test = 1.0"
     r = sjson.loads(s)
@@ -209,12 +214,12 @@ def testBugDecodeFailsOnStringWithDot():
 
 
 def testStringWithoutQuotesAsValueThrows():
-    with pytest.raises(Exception):
+    with pytest.raises(sjson.ParseException):
         sjson.loads("key = baz\n")
 
 
 def testStringWithoutClosingQuotesThrows():
-    with pytest.raises(Exception):
+    with pytest.raises(sjson.ParseException):
         sjson.loads('key = "baz\n')
 
 
@@ -249,23 +254,23 @@ def testStringWithEmptyRawLiteral():
 
 
 def testStringWithIncorrectlyTerminatedRawLiteral():
-    with pytest.raises(Exception):
+    with pytest.raises(sjson.ParseException):
         sjson.loads("""foo = [=[=]""")
-    with pytest.raises(Exception):
+    with pytest.raises(sjson.ParseException):
         sjson.loads("""foo = [=[]]""")
-    with pytest.raises(Exception):
+    with pytest.raises(sjson.ParseException):
         sjson.loads("""foo = [=[]=""")
 
 
 def testUndelimitedMapThrows():
-    with pytest.raises(Exception):
+    with pytest.raises(sjson.ParseException):
         sjson.loads('foo = { bar = "value", baz = { ui = "foo",')
 
 
 def testInvalidRawQuotedStringStart():
-    with pytest.raises(Exception):
+    with pytest.raises(sjson.ParseException):
         sjson.loads("foo = [=? wrong ?=]")
-    with pytest.raises(Exception):
+    with pytest.raises(sjson.ParseException):
         sjson.loads("foo = [=] wrong [=]")
 
 
@@ -307,7 +312,7 @@ def testCStyleCommentIsIgnored():
 
 
 def testNotClosedCStyleCommentThrows():
-    with pytest.raises(Exception):
+    with pytest.raises(sjson.ParseException):
         sjson.loads("""foo = /* bar * 23""")
 
 
@@ -319,7 +324,8 @@ def testCppStyleCommentIsIgnored():
 
 
 def testParseStringraySJSONExample():
-    r = sjson.loads("""// The script that should be started when the application runs.
+    r = sjson.loads(
+        """// The script that should be started when the application runs.
 boot_script = "boot"
 
 // The port on which the console server runs.
@@ -407,32 +413,33 @@ def testIndentWithNegativeNumberDoesNotIndent():
 
 
 def testDoubleColonSeparator():
-    assert sjson.loads("""{"smells-like" : "json"}""") == {'smells-like': 'json'}
+    assert sjson.loads("""{"smells-like" : "json"}""") == {
+        'smells-like': 'json'}
 
 
 def testUnknownEscapeGetsIgnored():
-    l = sjson.loads(r'foo = "Bar\lbaz"')
-    assert l['foo'] == r'Bar\lbaz'
+    r = sjson.loads(r'foo = "Bar\lbaz"')
+    assert r['foo'] == r'Bar\lbaz'
 
 
 def testPythonStyleString():
-    l = sjson.loads('''foo = """This is
+    r = sjson.loads('''foo = """This is
 multiline!"""''')
     assert (
-        l['foo']
+        r['foo']
         == """This is
 multiline!"""
     )
 
 
 def testQuadrupleQuotedString():
-    l = sjson.loads('''Foo = """"Why oh why""""''')
-    assert l['Foo'] == '"Why oh why"'
+    r = sjson.loads('''Foo = """"Why oh why""""''')
+    assert r['Foo'] == '"Why oh why"'
 
 
 def testQuintupleQuotedString():
-    l = sjson.loads('''Foo = """""Why oh why"""""''')
-    assert l['Foo'] == '""Why oh why""'
+    r = sjson.loads('''Foo = """""Why oh why"""""''')
+    assert r['Foo'] == '""Why oh why""'
 
 
 def testSixtupleQuotedStringIsInvalid():
@@ -441,13 +448,13 @@ def testSixtupleQuotedStringIsInvalid():
 
 
 def testPythonRawQuotedStringInsideLuaRawString():
-    l = sjson.loads('''foo = [=[ String """ string ]=]''')
-    assert l['foo'] == ''' String """ string '''
+    r = sjson.loads('''foo = [=[ String """ string ]=]''')
+    assert r['foo'] == ''' String """ string '''
 
 
 def testLuaRawQuotedStringInsidePythonRawString():
-    l = sjson.loads('''foo = """ String [=[ baz ]=] string """''')
-    assert l['foo'] == ''' String [=[ baz ]=] string '''
+    r = sjson.loads('''foo = """ String [=[ baz ]=] string """''')
+    assert r['foo'] == ''' String [=[ baz ]=] string '''
 
 
 def testEncodeUnknownTypeRaisesException():
@@ -459,5 +466,5 @@ class X:
 
 
 def testDecodeEscapedCharacters():
-    l = sjson.loads('''a = "\\b\\n\\t"''')
-    assert l['a'] == """\b\n\t"""
+    r = sjson.loads('''a = "\\b\\n\\t"''')
+    assert r['a'] == """\b\n\t"""