Subschema inlining on Newtype enums even with latest changes.

[bralax]

@GREsau With regards to #355 and #347, even on the latest alpha (1.0.0-alpha.16), I'm still seeing all subschemas getting inlined.

For example, using this code as my test:

use schemars::{generate::SchemaSettings, JsonSchema};

#[derive(JsonSchema)]
#[serde(tag = "type")]
pub enum Root {
    A(SubEnum1),
    B(SubEnum2),
}

#[derive(JsonSchema)]
#[serde(tag = "other_type")]
pub enum SubEnum1 {
    C(SubSchema1),
    D(SubSchema2),
}

#[derive(JsonSchema)]
#[serde(tag = "other_type")]
pub enum SubEnum2 {
    E(SubSchema3),
    F(SubSchema4),
    G(String),
    H{id: String}
}

#[derive(JsonSchema)]
pub struct SubSchema1 {
    pub w: String,
}

#[derive(JsonSchema)]
pub struct SubSchema2 {
    pub x: String,
}

#[derive(JsonSchema)]
pub struct SubSchema3 {
    pub y: String,
}

#[derive(JsonSchema)]
pub struct SubSchema4 {
    pub z: String,
}

fn main() {
    let mut settings = SchemaSettings::draft2020_12();
    settings.inline_subschemas = false;
    let schema = settings.into_generator().root_schema_for::<Root>();
    println!("{}", serde_json::to_string_pretty(&schema).unwrap());
}

I get the following schema:

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "Root",
  "oneOf": [
    {
      "type": "object",
      "properties": {
        "type": {
          "type": "string",
          "const": "A"
        }
      },
      "oneOf": [
        {
          "type": "object",
          "properties": {
            "other_type": {
              "type": "string",
              "const": "C"
            },
            "w": {
              "type": "string"
            }
          },
          "required": [
            "other_type",
            "w"
          ]
        },
        {
          "type": "object",
          "properties": {
            "other_type": {
              "type": "string",
              "const": "D"
            },
            "x": {
              "type": "string"
            }
          },
          "required": [
            "other_type",
            "x"
          ]
        }
      ],
      "required": [
        "type"
      ]
    },
    {
      "type": "object",
      "properties": {
        "type": {
          "type": "string",
          "const": "B"
        }
      },
      "oneOf": [
        {
          "type": "object",
          "properties": {
            "other_type": {
              "type": "string",
              "const": "E"
            },
            "y": {
              "type": "string"
            }
          },
          "required": [
            "other_type",
            "y"
          ]
        },
        {
          "type": "object",
          "properties": {
            "other_type": {
              "type": "string",
              "const": "F"
            },
            "z": {
              "type": "string"
            }
          },
          "required": [
            "other_type",
            "z"
          ]
        },
        {
          "type": "object",
          "properties": {
            "other_type": {
              "type": "string",
              "const": "G"
            }
          },
          "required": [
            "other_type"
          ]
        },
        {
          "type": "object",
          "properties": {
            "id": {
              "type": "string"
            },
            "other_type": {
              "type": "string",
              "const": "H"
            }
          },
          "required": [
            "other_type",
            "id"
          ]
        }
      ],
      "required": [
        "type"
      ]
    }
  ]
}

This schema does not end up with any definitions section and every model and enum other than Root is inlined. In this case also nothing is marked as deny_unknown_fields so it shouldn't be falling into that edge case.

[GREsau]

That's odd - it looks like the changes around internally-tagged newtype variants weren't actually included in the published crate. It's possible I forgot to update my local master branch before publishing...

I've now published v1.0.0-alpha.17, which definitely does include the change! In this version, the output from your example is:

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "Root",
  "oneOf": [
    {
      "type": "object",
      "properties": {
        "type": {
          "type": "string",
          "const": "A"
        }
      },
      "$ref": "#/$defs/SubEnum1",
      "required": [
        "type"
      ]
    },
    {
      "type": "object",
      "properties": {
        "type": {
          "type": "string",
          "const": "B"
        }
      },
      "$ref": "#/$defs/SubEnum2",
      "required": [
        "type"
      ]
    }
  ],
  "$defs": {
    "SubEnum1": {
      "oneOf": [
        {
          "type": "object",
          "properties": {
            "other_type": {
              "type": "string",
              "const": "C"
            }
          },
          "$ref": "#/$defs/SubSchema1",
          "required": [
            "other_type"
          ]
        },
        {
          "type": "object",
          "properties": {
            "other_type": {
              "type": "string",
              "const": "D"
            }
          },
          "$ref": "#/$defs/SubSchema2",
          "required": [
            "other_type"
          ]
        }
      ]
    },
    "SubEnum2": {
      "oneOf": [
        {
          "type": "object",
          "properties": {
            "other_type": {
              "type": "string",
              "const": "E"
            }
          },
          "$ref": "#/$defs/SubSchema3",
          "required": [
            "other_type"
          ]
        },
        {
          "type": "object",
          "properties": {
            "other_type": {
              "type": "string",
              "const": "F"
            }
          },
          "$ref": "#/$defs/SubSchema4",
          "required": [
            "other_type"
          ]
        },
        {
          "type": "object",
          "properties": {
            "other_type": {
              "type": "string",
              "const": "G"
            }
          },
          "required": [
            "other_type"
          ]
        },
        {
          "type": "object",
          "properties": {
            "id": {
              "type": "string"
            },
            "other_type": {
              "type": "string",
              "const": "H"
            }
          },
          "required": [
            "other_type",
            "id"
          ]
        }
      ]
    },
    "SubSchema1": {
      "type": "object",
      "properties": {
        "w": {
          "type": "string"
        }
      },
      "required": [
        "w"
      ]
    },
    "SubSchema2": {
      "type": "object",
      "properties": {
        "x": {
          "type": "string"
        }
      },
      "required": [
        "x"
      ]
    },
    "SubSchema3": {
      "type": "object",
      "properties": {
        "y": {
          "type": "string"
        }
      },
      "required": [
        "y"
      ]
    },
    "SubSchema4": {
      "type": "object",
      "properties": {
        "z": {
          "type": "string"
        }
      },
      "required": [
        "z"
      ]
    }
  }
}

[GREsau]

Oh by the way, the schema for the SubEnum2::G(String) variant doesn't really make sense because the variant itself can't be serialized (the variant tag can't be set as a property inside a string). Trying to serialize it causes a runtime error from serde: cannot serialize tagged newtype variant SubEnum2::G containing a string