[BUG] [dart-dio] Output document is not enclosed in symbols when example is a String type

Description

Output document is not enclosed in symbols when example is a String type.

Input

# openapi-3.0.yaml
openapi: 3.0.3
...
paths:
  /test:
    get:
      parameters:
        - name: query
          in: query
          required: true
          schema:
            type: string
            example: This is a sample string
      responses:
        "200":
          description: description
...

Outout

// Example code in doc/DefaultApi.md
...
final api = TestOpenapiDart().getDefaultApi();
final String query = This is a sample string; // String | 
...

Expected Output

// Example code in doc/DefaultApi.md
...
final api = TestOpenapiDart().getDefaultApi();
final String query = 'This is a sample string'; // String | 
...

openapi-generator version

6.3.0

OpenAPI declaration file content or url

java -jar openapi-generator-cli.jar generate -g dart-dio ...

Generation Details

Related issues/PRs

Suggest a fix

Check the type and add a symbol if it is a String.

Start with the dart-dio generator using the supplied OpenAPI YAML and CLI command, then inspect the generated doc/DefaultApi.md. Compare the String example with the expected quoted output; done means String examples are enclosed in quotes while other types remain unchanged.