Improve parity between Java and Kotlin router DSL

This commit adds variants with pattern + predicate to
Kotlin router DSLs, and vararg where necessary.

Closes gh-23524

spring-webmvc/src/main/kotlin/org/springframework/web/servlet/function/RouterFunctionDsl.kt

@@ -145,13 +145,25 @@ class RouterFunctionDsl(private val init: (RouterFunctionDsl.() -> Unit)) {
 	fun String.nest(r: (RouterFunctionDsl.() -> Unit)) = path(this).nest(r)
 
 	/**
-	 * Route to the given handler function if the given request predicate applies.
-	 * @see RouterFunctions.route
+	 * Adds a route to the given handler function that handles all HTTP `GET` requests
+	 * that match the given pattern.
+	 * @param pattern the pattern to match to
 	 */
 	fun GET(pattern: String, f: (ServerRequest) -> ServerResponse) {
 		builder.GET(pattern, HandlerFunction(f))
 	}
 
+	/**
+	 * Adds a route to the given handler function that handles all HTTP `GET` requests
+	 * that match the given pattern.
+	 * @param pattern the pattern to match to
+	 * @param predicate additional predicate to match
+	 * @since 5.2
+	 */
+	fun GET(pattern: String, predicate: RequestPredicate, f: (ServerRequest) -> ServerResponse) {
+		builder.GET(pattern, predicate, HandlerFunction(f))
+	}
+
 	/**
 	 * Return a [RequestPredicate] that matches if request's HTTP method is `GET`
 	 * and the given `pattern` matches against the request path.
@@ -160,13 +172,25 @@ class RouterFunctionDsl(private val init: (RouterFunctionDsl.() -> Unit)) {
 	fun GET(pattern: String): RequestPredicate = RequestPredicates.GET(pattern)
 
 	/**
-	 * Route to the given handler function if the given request predicate applies.
-	 * @see RouterFunctions.route
+	 * Adds a route to the given handler function that handles all HTTP `HEAD` requests
+	 * that match the given pattern.
+	 * @param pattern the pattern to match to
 	 */
 	fun HEAD(pattern: String, f: (ServerRequest) -> ServerResponse) {
 		builder.HEAD(pattern, HandlerFunction(f))
 	}
 
+	/**
+	 * Adds a route to the given handler function that handles all HTTP `HEAD` requests
+	 * that match the given pattern.
+	 * @param pattern the pattern to match to
+	 * @param predicate additional predicate to match
+	 * @since 5.2
+	 */
+	fun HEAD(pattern: String, predicate: RequestPredicate, f: (ServerRequest) -> ServerResponse) {
+		builder.HEAD(pattern, predicate, HandlerFunction(f))
+	}
+
 	/**
 	 * Return a [RequestPredicate] that matches if request's HTTP method is `HEAD`
 	 * and the given `pattern` matches against the request path.
@@ -175,13 +199,25 @@ class RouterFunctionDsl(private val init: (RouterFunctionDsl.() -> Unit)) {
 	fun HEAD(pattern: String): RequestPredicate = RequestPredicates.HEAD(pattern)
 
 	/**
-	 * Route to the given handler function if the given `POST` predicate applies.
-	 * @see RouterFunctions.route
+	 * Adds a route to the given handler function that handles all HTTP `POST` requests
+	 * that match the given pattern.
+	 * @param pattern the pattern to match to
 	 */
 	fun POST(pattern: String, f: (ServerRequest) -> ServerResponse) {
 		builder.POST(pattern, HandlerFunction(f))
 	}
 
+	/**
+	 * Adds a route to the given handler function that handles all HTTP `POST` requests
+	 * that match the given pattern.
+	 * @param pattern the pattern to match to
+	 * @param predicate additional predicate to match
+	 * @since 5.2
+	 */
+	fun POST(pattern: String, predicate: RequestPredicate, f: (ServerRequest) -> ServerResponse) {
+		builder.POST(pattern, predicate, HandlerFunction(f))
+	}
+
 	/**
 	 * Return a [RequestPredicate] that matches if request's HTTP method is `POST`
 	 * and the given `pattern` matches against the request path.
@@ -190,13 +226,25 @@ class RouterFunctionDsl(private val init: (RouterFunctionDsl.() -> Unit)) {
 	fun POST(pattern: String): RequestPredicate = RequestPredicates.POST(pattern)
 
 	/**
-	 * Route to the given handler function if the given `PUT` predicate applies.
-	 * @see RouterFunctions.route
+	 * Adds a route to the given handler function that handles all HTTP `PUT` requests
+	 * that match the given pattern.
+	 * @param pattern the pattern to match to
 	 */
 	fun PUT(pattern: String, f: (ServerRequest) -> ServerResponse) {
 		builder.PUT(pattern, HandlerFunction(f))
 	}
 
+	/**
+	 * Adds a route to the given handler function that handles all HTTP `PUT` requests
+	 * that match the given pattern.
+	 * @param pattern the pattern to match to
+	 * @param predicate additional predicate to match
+	 * @since 5.2
+	 */
+	fun PUT(pattern: String, predicate: RequestPredicate, f: (ServerRequest) -> ServerResponse) {
+		builder.PUT(pattern, predicate, HandlerFunction(f))
+	}
+
 	/**
 	 * Return a [RequestPredicate] that matches if request's HTTP method is `PUT`
 	 * and the given `pattern` matches against the request path.
@@ -205,13 +253,25 @@ class RouterFunctionDsl(private val init: (RouterFunctionDsl.() -> Unit)) {
 	fun PUT(pattern: String): RequestPredicate = RequestPredicates.PUT(pattern)
 
 	/**
-	 * Route to the given handler function if the given `PATCH` predicate applies.
-	 * @see RouterFunctions.route
+	 * Adds a route to the given handler function that handles all HTTP `PATCH` requests
+	 * that match the given pattern.
+	 * @param pattern the pattern to match to
 	 */
 	fun PATCH(pattern: String, f: (ServerRequest) -> ServerResponse) {
 		builder.PATCH(pattern, HandlerFunction(f))
 	}
 
+	/**
+	 * Adds a route to the given handler function that handles all HTTP `PATCH` requests
+	 * that match the given pattern.
+	 * @param pattern the pattern to match to
+	 * @param predicate additional predicate to match
+	 * @since 5.2
+	 */
+	fun PATCH(pattern: String, predicate: RequestPredicate, f: (ServerRequest) -> ServerResponse) {
+		builder.PATCH(pattern, predicate, HandlerFunction(f))
+	}
+
 	/**
 	 * Return a [RequestPredicate] that matches if request's HTTP method is `PATCH`
 	 * and the given `pattern` matches against the request path.
@@ -222,13 +282,25 @@ class RouterFunctionDsl(private val init: (RouterFunctionDsl.() -> Unit)) {
 	fun PATCH(pattern: String): RequestPredicate = RequestPredicates.PATCH(pattern)
 
 	/**
-	 * Route to the given handler function if the given `DELETE` predicate applies.
-	 * @see RouterFunctions.route
+	 * Adds a route to the given handler function that handles all HTTP `DELETE` requests
+	 * that match the given pattern.
+	 * @param pattern the pattern to match to
 	 */
 	fun DELETE(pattern: String, f: (ServerRequest) -> ServerResponse) {
 		builder.DELETE(pattern, HandlerFunction(f))
 	}
 
+	/**
+	 * Adds a route to the given handler function that handles all HTTP `DELETE` requests
+	 * that match the given pattern.
+	 * @param pattern the pattern to match to
+	 * @param predicate additional predicate to match
+	 * @since 5.2
+	 */
+	fun DELETE(pattern: String, predicate: RequestPredicate, f: (ServerRequest) -> ServerResponse) {
+		builder.DELETE(pattern, predicate, HandlerFunction(f))
+	}
+
 	/**
 	 * Return a [RequestPredicate] that matches if request's HTTP method is `DELETE`
 	 * and the given `pattern` matches against the request path.
@@ -239,13 +311,25 @@ class RouterFunctionDsl(private val init: (RouterFunctionDsl.() -> Unit)) {
 	fun DELETE(pattern: String): RequestPredicate = RequestPredicates.DELETE(pattern)
 
 	/**
-	 * Route to the given handler function if the given OPTIONS predicate applies.
-	 * @see RouterFunctions.route
+	 * Adds a route to the given handler function that handles all HTTP `OPTIONS` requests
+	 * that match the given pattern.
+	 * @param pattern the pattern to match to
 	 */
 	fun OPTIONS(pattern: String, f: (ServerRequest) -> ServerResponse) {
 		builder.OPTIONS(pattern, HandlerFunction(f))
 	}
 
+	/**
+	 * Adds a route to the given handler function that handles all HTTP `OPTIONS` requests
+	 * that match the given pattern.
+	 * @param pattern the pattern to match to
+	 * @param predicate additional predicate to match
+	 * @since 5.2
+	 */
+	fun OPTIONS(pattern: String, predicate: RequestPredicate, f: (ServerRequest) -> ServerResponse) {
+		builder.OPTIONS(pattern, predicate, HandlerFunction(f))
+	}
+
 	/**
 	 * Return a [RequestPredicate] that matches if request's HTTP method is `OPTIONS`
 	 * and the given `pattern` matches against the request path.

spring-webmvc/src/test/kotlin/org/springframework/web/servlet/function/RouterFunctionDslTests.kt

@@ -55,6 +55,15 @@ class RouterFunctionDslTests {
 		assertThat(sampleRouter().route(request).isPresent).isTrue()
 	}
 
+	@Test
+	fun acceptAndPOSTWithRequestPredicate() {
+		val servletRequest = MockHttpServletRequest("POST", "/api/bar/")
+		servletRequest.addHeader(ACCEPT, APPLICATION_JSON_VALUE)
+		servletRequest.addHeader(CONTENT_TYPE, APPLICATION_JSON_VALUE)
+		val request = DefaultServerRequest(servletRequest, emptyList())
+		assertThat(sampleRouter().route(request).isPresent).isTrue()
+	}
+
 	@Test
 	fun contentType() {
 		val servletRequest = MockHttpServletRequest("GET", "/content")
@@ -120,6 +129,7 @@ class RouterFunctionDslTests {
 		(GET("/foo/") or GET("/foos/")) { req -> handle(req) }
 		"/api".nest {
 			POST("/foo/", ::handleFromClass)
+			POST("/bar/", contentType(APPLICATION_JSON), ::handleFromClass)
 			PUT("/foo/", :: handleFromClass)
 			PATCH("/foo/") {
 				ok().build()
@@ -148,10 +158,10 @@ class RouterFunctionDslTests {
 		path("/baz", ::handle)
 		GET("/rendering") { RenderingResponse.create("index").build() }
 	}
+
+	@Suppress("UNUSED_PARAMETER")
+	private fun handleFromClass(req: ServerRequest) = ServerResponse.ok().build()
 }
 
-@Suppress("UNUSED_PARAMETER")
-private fun handleFromClass(req: ServerRequest) = ServerResponse.ok().build()
-
 @Suppress("UNUSED_PARAMETER")
 private fun handle(req: ServerRequest) = ServerResponse.ok().build()