GH-161 Check if WebJarHandler is already registered (#166)

* Resolved #161 by checking first if a webjarhandler is registered

* Addressed PR comment and expanded unit test

* GH-166 Code review

---------

Co-authored-by: dzikoysk <[email protected]>

Author: sauterl

javalin-plugins/javalin-swagger-plugin/src/main/kotlin/io/javalin/openapi/plugin/swagger/SwaggerPlugin.kt

@@ -1,6 +1,7 @@
 package io.javalin.openapi.plugin.swagger
 
 import io.javalin.Javalin
+import io.javalin.http.HandlerType
 import io.javalin.plugin.Plugin
 import io.javalin.security.RouteRole
 
@@ -61,14 +62,19 @@ open class SwaggerPlugin @JvmOverloads constructor(private val configuration: Sw
             customStylesheetFiles = configuration.customStylesheetFiles,
             customJavaScriptFiles = configuration.customJavaScriptFiles
         )
+        /** Register handler for swagger ui */
+        app.get(configuration.uiPath, swaggerHandler, *configuration.roles)
 
-        val swaggerWebJarHandler = SwaggerWebJarHandler(
-            swaggerWebJarPath = configuration.webJarPath
-        )
-
-        app
-            .get(configuration.uiPath, swaggerHandler, *configuration.roles)
-            .get("${configuration.webJarPath}/*", swaggerWebJarHandler, *configuration.roles)
+        /** Register webjar handler if and only if there isn't already a [SwaggerWebJarHandler] at configured route */
+        app.javalinServlet().matcher
+            .findEntries(HandlerType.GET, "${configuration.webJarPath}/*")
+            .takeIf { routes -> routes.none { it.handler is SwaggerWebJarHandler } }
+            ?.run {
+                val swaggerWebJarHandler = SwaggerWebJarHandler(
+                    swaggerWebJarPath = configuration.webJarPath
+                )
+                app.get("${configuration.webJarPath}/*", swaggerWebJarHandler, *configuration.roles)
+            }
     }
 
-}
+}

javalin-plugins/javalin-swagger-plugin/src/test/kotlin/io/javalin/openapi/plugin/swagger/SwaggerPluginTest.kt

@@ -68,4 +68,100 @@ internal class SwaggerPluginTest {
             }
     }
 
-}
+    @Test
+    fun `should not fail if second swagger plugin is registered`(){
+        val swaggerConfiguration = SwaggerConfiguration();
+        val otherConfiguration = ExampleSwaggerPlugin();
+        Javalin.create{
+            it.plugins.register(SwaggerPlugin(swaggerConfiguration))
+            it.plugins.register(otherConfiguration)
+        }
+            .start(8080)
+            .use{
+                val javalinHost = "http://localhost:8080"
+                val webjarJsRoute = "/webjars/swagger-ui/${swaggerConfiguration.version}/swagger-ui-bundle.js"
+
+                val response = Unirest.get("$javalinHost/swagger")
+                    .asString()
+                    .body
+
+                assertThat(response).contains("""src="$webjarJsRoute"""")
+                assertThat(response).contains("""url: '/openapi?v=test'""")
+                assertThat(response).doesNotContain("""url: '/example-docs?v=test'""")
+
+                val resourceResponse = Unirest.get("$javalinHost$webjarJsRoute")
+                    .asString()
+                    .body
+
+                assertThat(resourceResponse).isNotBlank
+
+                val otherResponse = Unirest.get("$javalinHost/example-ui")
+                    .asString()
+                    .body
+
+                assertThat(otherResponse).contains("""url: '/example-docs?v=test'""")
+                assertThat(otherResponse).doesNotContain("""url: '/openapi?v=test'""")
+            }
+    }
+
+    @Test
+    fun `should not fail if second swagger plugin is registered with routes`(){
+        val swaggerConfiguration = SwaggerConfiguration();
+        val otherConfiguration = ExampleSwaggerPlugin();
+        Javalin.create{
+            it.plugins.register(SwaggerPlugin(swaggerConfiguration))
+            it.plugins.register(otherConfiguration)
+        }.get("/some/route/"){ ctx -> ctx.result("Hello World")}
+            .start(8080)
+            .use{
+                val javalinHost = "http://localhost:8080"
+
+                val webjarCssRoute = "/webjars/swagger-ui/${swaggerConfiguration.version}/swagger-ui.css"
+                val webjarJsRoute = "/webjars/swagger-ui/${swaggerConfiguration.version}/swagger-ui-bundle.js"
+                val webjarJsStandaloneRoute = "/webjars/swagger-ui/${swaggerConfiguration.version}/swagger-ui-standalone-preset.js"
+
+                val response = Unirest.get("$javalinHost/swagger")
+                    .asString()
+                    .body
+
+                assertThat(response).contains("""href="$webjarCssRoute"""")
+                assertThat(response).contains("""src="$webjarJsRoute"""")
+                assertThat(response).contains("""src="$webjarJsStandaloneRoute"""")
+                assertThat(response).contains("""url: '/openapi?v=test'""")
+                assertThat(response).doesNotContain("""url: '/example-docs?v=test'""")
+
+                var resourceResponse = Unirest.get("$javalinHost$webjarCssRoute")
+                    .asString()
+                    .body
+
+                assertThat(resourceResponse).isNotBlank
+
+                resourceResponse = Unirest.get("$javalinHost$webjarJsRoute")
+                    .asString()
+                    .body
+
+                assertThat(resourceResponse).isNotBlank
+
+                resourceResponse = Unirest.get("$javalinHost$webjarJsStandaloneRoute")
+                    .asString()
+                    .body
+
+                assertThat(resourceResponse).isNotBlank
+
+                val otherResponse = Unirest.get("$javalinHost/example-ui")
+                    .asString()
+                    .body
+
+                assertThat(otherResponse).contains("""url: '/example-docs?v=test'""")
+                assertThat(otherResponse).doesNotContain("""url: '/openapi?v=test'""")
+            }
+    }
+
+    class ExampleSwaggerPlugin : SwaggerPlugin(
+        SwaggerConfiguration().apply {
+            this.documentationPath = "/example-docs"
+            this.uiPath = "/example-ui"
+        }
+    )
+
+}