System.Text.json deserialize doesn't support case insensitive Hashset

[lyndaidaii]

Description

We initialized hashset with case insensitive in object, we used system.text.json deserialize content from json file to object.
Noticed that Hashset was case sensitive, not insensitive as expected

Reproduction Steps

public class Config
{
  public HashSet<string>Set {get; set;}
  public Config(){
      Set = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
  } 

// json contains a list of string. 
public class initialize
{
  var options = new JsonSerializerOptions
  {
      PropertyNameCaseInsensitive = true
  };
  Config config = JsonSerializer.Deserialize<Config>(json, options);
}

Expected behavior

expected to be case insensitive.

Actual behavior

HashSet is case sensitive

Regression?

No response

Known Workarounds

public class Config
{
  public HashSet<string>Set {get;}
  public Config(HashSet<string> set){
      Set = new HashSet<string>(set, StringComparer.OrdinalIgnoreCase);
  } 

// json contains a list of string. 
public class initialize
{
  var options = new JsonSerializerOptions
  {
      PropertyNameCaseInsensitive = true
  };
  Config config = JsonSerializer.Deserialize<Config>(json, options);
}

Configuration

No response

Other information

No response

[ghost]

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Issue Details

---

Description

We initialized hashset with case insensitive in object, we used system.text.json deserialize content from json file to object.
Noticed that Hashset was case sensitive, not insensitive as expected

Reproduction Steps

ExampleList
{
HashSet set;
example(){
set = new HashSet(StringComparison.OrdinalIgnoreCase)
}
}

json contains a list of string.
exampleList = JsonSerializer.Deserialize(json);
exampleList.set is case sensitive

Expected behavior

expected to be case insensitive.

Actual behavior

HashSet is case sensitive

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

No response

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

[danmoseley]

@lyndaidaii can you please update your sample with a minimal, runnable repro example? BTW you can use triple back ticks above and below to format as code.

[eiriktsarpalis]

Likely related to #30258. System.Text.Json does not currently support appending elements to properties with existing collections and we're looking to get this addressed in .NET 7.

[ghost]

This issue has been marked needs-author-action since it may be missing important information. Please refer to our contribution guidelines for tips on how to report issues effectively.

[lyndaidaii]

Likely related to #30258. System.Text.Json does not currently support appending elements to properties with existing collections and we're looking to get this addressed in .NET 7.

It's related to issue #30258, anyway, I updated the example above

[eiriktsarpalis]

Closing as duplicate of #30258. I should point out that the PropertyNameCaseInsensitive concerns matching JSON properties to POCO properties, and does not have any impact on the case sensitivity of deserialized dictionary types.