make param matcher slightly nicer

http4k · Oct 15, 2020 · 8674132 · 8674132
1 parent 04d40f2
commit 8674132
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Showing 3 changed files with 28 additions and 9 deletions.
diff --git a/http4k-core/src/main/kotlin/org/http4k/routing/ParameterMatchRoutingHttpHandler.kt b/http4k-core/src/main/kotlin/org/http4k/routing/ParameterMatchRoutingHttpHandler.kt
@@ -5,6 +5,8 @@ import org.http4k.core.HttpHandler
 import org.http4k.core.Request
 import org.http4k.core.Response
 import org.http4k.core.then
+import org.http4k.routing.RouterMatch.MatchingHandler
+import org.http4k.routing.RouterMatch.Unmatched
 
 sealed class ParameterMatch(private val predicate: (Request) -> Boolean) : (Request) -> Boolean by predicate {
     infix fun bind(handler: HttpHandler): RoutingHttpHandler = PredicatedHandler(predicate, handler)
@@ -18,12 +20,20 @@ sealed class ParameterMatch(private val predicate: (Request) -> Boolean) : (Requ
 }
 
 internal class PredicatedHandler(private val predicate: (Request) -> Boolean, private val handler: HttpHandler) : RoutingHttpHandler {
-    override fun withFilter(new: Filter) = throw UnsupportedOperationException("Not available at the top level")
-    override fun withBasePath(new: String) = throw UnsupportedOperationException("Not available at the top level")
-    override fun match(request: Request) = if (predicate(request)) RouterMatch.MatchingHandler(handler) else RouterMatch.Unmatched
+    override fun withFilter(new: Filter) = PredicatedHandler(predicate, when(handler) {
+        is RoutingHttpHandler -> handler.withFilter(new)
+        else -> new.then(handler)
+    })
+
+    override fun withBasePath(new: String) = when(handler) {
+        is RoutingHttpHandler -> handler.withBasePath(new)
+        else -> throw UnsupportedOperationException("Cannot apply new base path without binding to an HTTP verb")
+    }
+
+    override fun match(request: Request) = if (predicate(request)) MatchingHandler(handler) else Unmatched
 
     override fun invoke(request: Request): Response = when (val matchResult = match(request)) {
-        is RouterMatch.MatchingHandler -> matchResult(request)
+        is MatchingHandler -> matchResult(request)
         else -> routeNotFoundHandler(request)
     }
 }
@@ -34,17 +44,17 @@ internal data class ParameterMatchRoutingHttpHandler(
     private val notFoundHandler: HttpHandler = routeNotFoundHandler,
     private val methodNotAllowedHandler: HttpHandler = routeMethodNotAllowedHandler) : RoutingHttpHandler {
 
-    override fun match(request: Request) = if (!matched(request)) RouterMatch.Unmatched else httpHandler.match(request)
+    override fun match(request: Request) = if (!matched(request)) Unmatched else httpHandler.match(request)
 
     override fun invoke(request: Request): Response = when (val matchResult = match(request)) {
-        is RouterMatch.MatchingHandler -> matchResult(request)
+        is MatchingHandler -> matchResult(request)
         is RouterMatch.MethodNotMatched -> methodNotAllowedHandler(request)
-        is RouterMatch.Unmatched -> notFoundHandler(request)
+        is Unmatched -> notFoundHandler(request)
     }
 
     override fun withFilter(new: Filter): RoutingHttpHandler = ParameterMatchRoutingHttpHandler(
         matched,
-        new.then(httpHandler),
+        httpHandler.withFilter(new),
         new.then(notFoundHandler),
         new.then(methodNotAllowedHandler)
     )

diff --git a/http4k-core/src/main/kotlin/org/http4k/routing/TemplateRoutingHttpHandler.kt b/http4k-core/src/main/kotlin/org/http4k/routing/TemplateRoutingHttpHandler.kt
@@ -30,7 +30,10 @@ internal data class TemplateRoutingHttpHandler(
     }
 
     override fun withFilter(new: Filter): RoutingHttpHandler =
-        copy(httpHandler = new.then(httpHandler), notFoundHandler = new.then(notFoundHandler), methodNotAllowedHandler = new.then(methodNotAllowedHandler))
+        copy(httpHandler = new.then(httpHandler),
+            notFoundHandler = new.then(notFoundHandler),
+            methodNotAllowedHandler = new.then(methodNotAllowedHandler)
+        )
 
     override fun withBasePath(new: String): RoutingHttpHandler = copy(template = UriTemplate.from("$new/$template"))
 }
diff --git a/http4k-core/src/test/kotlin/org/http4k/routing/ParameterMatchRoutingHttpHandlerTest.kt b/http4k-core/src/test/kotlin/org/http4k/routing/ParameterMatchRoutingHttpHandlerTest.kt
@@ -3,6 +3,7 @@ package org.http4k.routing
 import com.natpryce.hamkrest.and
 import com.natpryce.hamkrest.assertion.assertThat
 import com.natpryce.hamkrest.present
+import com.natpryce.hamkrest.throws
 import org.http4k.core.Method.GET
 import org.http4k.core.Request
 import org.http4k.core.Response
@@ -31,6 +32,11 @@ class ParameterMatchRoutingHttpHandlerTest : RoutingHttpHandlerContract() {
         assertThat(withBasePath.matchAndInvoke(prefixReq), criteria)
         assertThat(withBasePath(prefixReq), criteria)
     }
+
+    @Test
+    fun `attempt to bind param handler without a verb`() {
+        assertThat({ routes(prefix bind (headers("host") bind { Response(OK) })) }, throws<UnsupportedOperationException>())
+    }
 }
 
 class ParameterMatchRoutingHttpHandlerAlternateTest : RoutingHttpHandlerContract() {