Deserialize a JSON string with the property name had no quotes

[WeihanLi]

Description

When I try to deserialize a JSON string with the property name had no ", it would throw an exception now, while it works with Newtonsoft.Json

Not sure if it's a problem, it may not a standard JSON

json sample:

{ CustomerId: "2929064f-1a22-4ece-947f-00eed7efed35"}

Reproduction Steps

Deserialize the previous JSON with system text json

System.Text.Json.JsonSerializer.Deserialize<JsonObject>(json);

Expected behavior

Success with JsonObject returned

Actual behavior

Got an exception likes follows:

System.Text.Json.JsonException: 
'C' is an invalid start of a property name. Expected a '"'. LineNumber: 0 | BytePositionInLine: 2.

Regression?

No response

Known Workarounds

No response

Configuration

.NET 6

Other information

No response

[ghost]

Tagging subscribers to this area: @dotnet/area-system-text-json, @gregsdennis
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Issue Details

---

Description

When I try to deserialize a JSON string with the property name had no ", it would throw an exception now, while it works with Newtonsoft.Json

json sample:

{ CustomerId: "2929064f-1a22-4ece-947f-00eed7efed35"}

Reproduction Steps

Deserialize the previous JSON with system text json

System.Text.Json.JsonSerializer.Deserialize<JsonObject>(json);

Expected behavior

Success with JsonObject returned

Actual behavior

Got an exception likes follows:

System.Text.Json.JsonException: 
'C' is an invalid start of a property name. Expected a '"'. LineNumber: 0 | BytePositionInLine: 2.

Regression?

No response

Known Workarounds

No response

Configuration

.NET 6

Other information

No response

Author:	WeihanLi
Assignees:	-
Labels:	area-System.Text.Json, untriaged
Milestone:	-

[WeihanLi]

relates to #32291

[eiriktsarpalis]

Property names lacking quotes is not valid JSON, but we might consider offering an optional flag that enables support. Closing as duplicate of #32291.