convertSwagger2markup fails with NPE with swagger files with schema json objects

[fooinha]

convertSwagger2markup fails with NPE.

This happens because if input swagger file has json objects schema like this one

      "schema" : {
          "$ref" : "#/definitions/APIResult"
      }

When removing all schema json nodes from input swagger file, the generation finishes without error.

pom.xml

        <swagger2markup.version>1.2.0</swagger2markup.version>

Stacktrace

Failed to execute goal 'convertSwagger2markup'
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:212)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
	at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
	at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
	at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
	at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863)
	at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
	at org.apache.maven.cli.MavenCli.main(MavenCli.java:199)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
	at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
	at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: org.apache.maven.plugin.MojoFailureException: Failed to execute goal 'convertSwagger2markup'
	at io.github.swagger2markup.Swagger2MarkupMojo.execute(Swagger2MarkupMojo.java:74)
	at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207)
	... 20 more
Caused by: java.lang.NullPointerException
	at io.github.swagger2markup.internal.adapter.PropertyAdapter.getType(PropertyAdapter.java:116)
	at io.github.swagger2markup.internal.adapter.PropertyAdapter.getType(PropertyAdapter.java:123)
	at io.github.swagger2markup.internal.component.ResponseComponent.lambda$apply$1(ResponseComponent.java:106)
	at java.util.TreeMap.forEach(TreeMap.java:1001)
	at io.github.swagger2markup.internal.component.ResponseComponent.apply(ResponseComponent.java:82)
	at io.github.swagger2markup.internal.component.PathOperationComponent.buildResponsesSection(PathOperationComponent.java:227)
	at io.github.swagger2markup.internal.component.PathOperationComponent.apply(PathOperationComponent.java:106)
	at io.github.swagger2markup.internal.document.PathsDocument.applyPathOperationComponent(PathsDocument.java:223)
	at io.github.swagger2markup.internal.document.PathsDocument.buildOperation(PathsDocument.java:207)
	at io.github.swagger2markup.internal.document.PathsDocument.lambda$null$1(PathsDocument.java:133)
	at java.lang.Iterable.forEach(Iterable.java:75)
	at io.github.swagger2markup.internal.document.PathsDocument.lambda$buildsPathsSection$2(PathsDocument.java:133)
	at java.util.TreeMap.forEach(TreeMap.java:1001)
	at io.github.swagger2markup.internal.document.PathsDocument.buildsPathsSection(PathsDocument.java:127)
	at io.github.swagger2markup.internal.document.PathsDocument.apply(PathsDocument.java:103)
	at io.github.swagger2markup.Swagger2MarkupConverter.applyPathsDocument(Swagger2MarkupConverter.java:197)
	at io.github.swagger2markup.Swagger2MarkupConverter.toFolder(Swagger2MarkupConverter.java:182)
	at io.github.swagger2markup.Swagger2MarkupMojo.execute(Swagger2MarkupMojo.java:69)
	... 22 more

[fooinha]

Maybe a duplicate of Swagger2Markup/swagger2markup#213

[RobWin]

Hi, could you please provide a minimal Swagger Spec to reproduce this issue?
Btw if you use and like Swagger2markup, we would love to get your GitHub Star.

[fooinha]

Hi, here you go. Thanx.

{
  "swagger" : "2.0",
  "info" : {
    "description" : "description",
    "version" : "v1",
    "title" : "title",
    "contact" : {
      "name" : "contact",
      "url" : "foo.tld",
      "email" : "noone@foo.tld"
    }
  },
  "host" : "localhost:8000",
  "basePath" : "/",
  "tags" : [ {
    "name" : "stuff",
    "description" : "workers Operations"
  }, {
    "name" : "things",
    "description" : "things Operations"
  }, {
    "name" : "choices",
    "description" : "choices Operations"
  } ],
  "schemes" : [ "http", "https" ],
  "paths" : {
    "/stuff" : {
      "get" : {
        "tags" : [ "stuff" ],
        "summary" : "Lists a page for Stuff stored in the Database",
        "description" : "",
        "operationId" : "listBotnets",
        "consumes" : [ "application/json" ],
        "produces" : [ "application/json" ],
        "parameters" : [ {
          "name" : "page",
          "in" : "query",
          "description" : "page",
          "required" : false,
          "type" : "integer",
          "default" : 1,
          "format" : "int32"
        } ],
        "responses" : {
          "200" : {
            "description" : "Lists a page for Stuff stored in the Database",
            "schema" : {
              "type" : "array",
              "items" : {
                "$ref" : "#/definitions/workersData"
              }
            },
            "headers" : {
              "Link" : {
                "type" : "array",
                "description" : "Links for pagination (RFC5899)",
                "items" : {
                  "$ref" : "#/definitions/Link"
                }
              }
            }
          }
        }
      },
      "post" : {
        "tags" : [ "stuff" ],
        "summary" : "Creates a new workers entry and returning it's ID",
        "description" : "",
        "operationId" : "createworkers",
        "consumes" : [ "application/json" ],
        "produces" : [ "application/json" ],
        "parameters" : [ {
          "in" : "body",
          "name" : "workers",
          "description" : "workers Data for creation",
          "required" : true,
          "schema" : {
            "$ref" : "#/definitions/workersData"
          }
        } ],
        "responses" : {
          "303" : {
            "description" : "Redirects to created workers URL"
          },
          "400" : {
            "description" : "Invalid data"
          },
          "500" : {
            "description" : "If an internal error happens"
          }
        }
      }
    }
  },
  "definitions" : {
    "workersData" : {
      "type" : "object",
      "properties" : {
        "links" : {
          "type" : "array",
          "xml" : {
            "name" : "_links"
          },
          "items" : {
            "$ref" : "#/definitions/Link"
          }
        },
        "id" : {
          "type" : "string",
          "format" : "uuid"
        },
        "name" : {
          "type" : "string"
        },
        "variantId" : {
          "type" : "string",
          "format" : "uuid"
        },
        "active" : {
          "type" : "boolean",
          "default" : false
        },
        "description" : {
          "type" : "string"
        }
      }
    },
    "UriBuilder" : {
      "type" : "object"
    },
    "Link" : {
      "type" : "object",
      "properties" : {
        "params" : {
          "type" : "object",
          "additionalProperties" : {
            "type" : "string"
          }
        },
        "title" : {
          "type" : "string"
        },
        "uriBuilder" : {
          "$ref" : "#/definitions/UriBuilder"
        },
        "uri" : {
          "type" : "string",
          "format" : "uri"
        },
        "rel" : {
          "type" : "string"
        },
        "rels" : {
          "type" : "array",
          "items" : {
            "type" : "string"
          }
        },
        "type" : {
          "type" : "string"
        }
      }
    }
  }
}

[RobWin]

The definitions section is missing. Is this by mistake?

[fooinha]

Yes. sorry. I made that mistake by creating the minimal version. I'll try to do it again. Thanx.

[RobWin]

You can edit the existing comment.

[fooinha]

Debugging it further, i see that this happens while processing response headers

https://github.com/Swagger2Markup/swagger2markup/blob/v1.2.0/src/main/java/io/github/swagger2markup/internal/component/ResponseComponent.java#L106

-->

https://github.com/Swagger2Markup/swagger2markup/blob/v1.2.0/src/main/java/io/github/swagger2markup/internal/adapter/PropertyAdapter.java#L123

definitionDocumentResolver == null ?

---

It works if we remove the $ from ref

 "$ref" : "#/definitions/Link"

Thanx