Faulty Transformation of Element with Type Boolean + Enum

[keil]

Description

We are using an API defining a Boolean-like-element build upon an enum containing boolean values true and false. The element is defined as follows:

  Boolean:
    type: boolean
    description: True or False indicator
    enum:
      - true
      - false

In general, true and false are interpreted as the boolean values true and false. However, the code-generated generates the following code fragment:

public enum ModelBoolean {
  
  TRUE("true"),
  
  FALSE("false");

  private Boolean value;

  ModelBoolean(Boolean value) {
    this.value = value;
  }

  @JsonValue
  public Boolean getValue() {
    return value;
  }

  @Override
  public String toString() {
    return String.valueOf(value);
  }


  @JsonCreator
  public static ModelBoolean fromValue(String text) {
    for (ModelBoolean b : ModelBoolean.values()) {
      if (String.valueOf(b.value).equals(text)) {
        return b;
      }
    }
    return null;
  }
}

Here, true and false are interpreted as string values, whereas the constructor of ModelBoolean requests a Boolean value. In short, this is not a valid Java code.

Note: A similar result appears when using JavaScript as the target language.

Swagger-codegen version

Version 2.4.17 (swagger-codegen-maven-plugin) or SwaggerHub

Swagger declaration file content or url

swagger: '2.0'
info:
  description: Demo
  version: 1.0.0
  title: Demo for Boolean-element Bug
schemes:
  - https
consumes:
  - application/json
produces:
  - application/json
paths:
  /users:
    get:
      summary: Returns a list of users.
      description: Optional extended description in Markdown.
      produces:
        - application/json
      responses:
        200:
          description: OK
definitions:
  Boolean:
    type: boolean
    description: True or False indicator
    enum:
      - true
      - false

Command line used for generation

Steps to reproduce

• Use swagger codegen (for example SwaggerHub) to generate Java code.

Related issues/PRs

Suggest a fix/enhancement

[keil]

In addition:

A similar problem exists when using the number data type.

  Number:
    type: number
    description: numbers
    enum:
      - 0
      - 1
      - 2
      - 3

The Number element results in the following Java code.

public enum Number {
  
  _0("0"),
  
  _1("1"),
  
  _2("2"),
  
  _3("3");

  private BigDecimal value;

  Number(BigDecimal value) {
    this.value = value;
  }

  public BigDecimal getValue() {
    return value;
  }

  @Override
  public String toString() {
    return String.valueOf(value);
  }

  public static Number fromValue(String text) {
    for (Number b : Number.values()) {
      if (String.valueOf(b.value).equals(text)) {
        return b;
      }
    }
    return null;
  }

  public static class Adapter extends TypeAdapter<Number> {
    @Override
    public void write(final JsonWriter jsonWriter, final Number enumeration) throws IOException {
      jsonWriter.value(enumeration.getValue());
    }

    @Override
    public Number read(final JsonReader jsonReader) throws IOException {
      BigDecimal value = jsonReader.nextBigDecimal();
      return Number.fromValue(String.valueOf(value));
    }
  }
}

Again, this is not a valid Java code. The number values are interpreted as string values, whereas the constructor request a value of type BigDecimal.

And, a similar picture is when using the integer data type.

Integer:
   type: integer
   description: integers
   enum:
     - 0
     - 1
     - 2
     - 3

public enum Integer {
  
  NUMBER_0(0),
  
  NUMBER_1(1),
  
  NUMBER_2(2),
  
  NUMBER_3(3);

  private Integer value;

  Integer(Integer value) {
    this.value = value;
  }

  public Integer getValue() {
    return value;
  }

  @Override
  public String toString() {
    return String.valueOf(value);
  }

  public static Integer fromValue(String text) {
    for (Integer b : Integer.values()) {
      if (String.valueOf(b.value).equals(text)) {
        return b;
      }
    }
    return null;
  }

  public static class Adapter extends TypeAdapter<Integer> {
    @Override
    public void write(final JsonWriter jsonWriter, final Integer enumeration) throws IOException {
      jsonWriter.value(enumeration.getValue());
    }

    @Override
    public Integer read(final JsonReader jsonReader) throws IOException {
      Integer value = jsonReader.nextInteger();
      return Integer.fromValue(String.valueOf(value));
    }
  }
}

Here, int and Integer are not compatible. Moreover, the method call jsonWriter.value(enumeration.getValue()) is not applicatble vor values of type Integer, only for int values.

[keil]

Unfortunately, the provided fix does not solve the problem! The generated Java code still looks as follows:

/**
 * True or False indicator
 */
@JsonAdapter(ModelBoolean.Adapter.class)
public enum ModelBoolean {
  
  TRUE("true"),
  
  FALSE("false");

  private Boolean value;

  ModelBoolean(Boolean value) {
    this.value = value;
  }

  public Boolean getValue() {
    return value;
  }

  @Override
  public String toString() {
    return String.valueOf(value);
  }

  public static ModelBoolean fromValue(String text) {
    for (ModelBoolean b : ModelBoolean.values()) {
      if (String.valueOf(b.value).equals(text)) {
        return b;
      }
    }
    return null;
  }

  public static class Adapter extends TypeAdapter<ModelBoolean> {
    @Override
    public void write(final JsonWriter jsonWriter, final ModelBoolean enumeration) throws IOException {
      jsonWriter.value(enumeration.getValue());
    }

    @Override
    public ModelBoolean read(final JsonReader jsonReader) throws IOException {
      Boolean value = jsonReader.nextBoolean();
      return ModelBoolean.fromValue(String.valueOf(value));
    }
  }
}

This is not a valid Java code. The constructor requires a value of type Boolean ModelBoolean(Boolean value), but is called with values of type String TRUE("true").

Tested with Swagegr Codegen Version 2.4.18 and version 3.0.24. Both sould include the fix.