Add rate limit headers before returning response by default (#78)

* fix: rate limit headers not included in response

* docs: add rate limit headers before returning response

* test: add test for rate limit headers

* Bump minor version

---------

Co-authored-by: Ido Flax <[email protected]>

Author: king-phyte

documentation/mkdocs/docs/ktor-server-rate-limiting/index.md

@@ -43,8 +43,8 @@ routing {
       whiteListedHosts = setOf("trusted-host.com")
       blackListedAgents = setOf("malicious-agent")
       rateLimitExceededHandler = { rateLimiterResponse ->
+        ...
         respond(HttpStatusCode.TooManyRequests, rateLimiterResponse.message)
-          ...
       }
     }
 
@@ -92,10 +92,10 @@ routing {
 
     rateLimitExceededHandler = { limitedBy ->
         // Respond with a 429 status and appropriate headers for rate-limited callers
-        respond(HttpStatusCode.TooManyRequests, "Rate limit exceeded: ${limitedBy.message}")
         response.headers.append("X-RateLimit-Limit", "${limitedBy.rateLimiter.capacity}")
         response.headers.append("X-RateLimit-Measured-by", limitedBy.rateLimiter.callVolumeUnit.name)
         response.headers.append("X-RateLimit-Reset", "${limitedBy.resetIn.inWholeMilliseconds}")
+        respond(HttpStatusCode.TooManyRequests, "Rate limit exceeded: ${limitedBy.message}")
     }
 
 ```

gradle.properties

@@ -3,7 +3,7 @@ github.repository.name=extra-ktor-plugins
 kotlin.native.cacheKind.linuxX64=none
 kotlin.native.ignoreDisabledTargets=true
 gradle.publish.enable.module-metadata=true
-version=2.1.1
+version=2.1.2
 gpr.user=flaxoos
 org.gradle.jvmargs=-Xmx2g -XX:MaxMetaspaceSize=2g
-kotlin.mpp.applyDefaultHierarchyTemplate=false
+kotlin.mpp.applyDefaultHierarchyTemplate=false

ktor-server-rate-limiting/src/commonMain/kotlin/io/github/flaxoos/ktor/server/plugins/ratelimiter/RateLimitingConfiguration.kt

@@ -83,13 +83,13 @@ class RateLimitingConfiguration {
      */
     var rateLimitExceededHandler: suspend ApplicationCall.(RateLimiterResponse.LimitedBy) -> Unit =
         { rateLimiterResponse ->
-            respond(HttpStatusCode.TooManyRequests, "$RATE_LIMIT_EXCEEDED_MESSAGE: ${rateLimiterResponse.message}")
             this.response.headers.append("$X_RATE_LIMIT-Limit", "${rateLimiterResponse.rateLimiter.capacity}")
             this.response.headers.append(
                 "$X_RATE_LIMIT-Measured-by",
                 rateLimiterResponse.rateLimiter.callVolumeUnit.name,
             )
             this.response.headers.append("$X_RATE_LIMIT-Reset", "${rateLimiterResponse.resetIn.inWholeMilliseconds}")
+            respond(HttpStatusCode.TooManyRequests, "$RATE_LIMIT_EXCEEDED_MESSAGE: ${rateLimiterResponse.message}")
         }
 
     /**

ktor-server-rate-limiting/src/jvmTest/kotlin/io/github/flaxoos/ktor/server/plugins/ratelimiter/RateLimitingPluginTest.kt

@@ -11,6 +11,7 @@ import io.kotest.core.spec.style.scopes.FunSpecContainerScope
 import io.kotest.datatest.withData
 import io.kotest.inspectors.forAll
 import io.kotest.matchers.collections.shouldContain
+import io.kotest.matchers.collections.shouldContainAll
 import io.kotest.matchers.collections.shouldContainOnly
 import io.kotest.matchers.comparables.shouldBeLessThan
 import io.ktor.client.HttpClient
@@ -347,6 +348,7 @@ class RateLimitingPluginTest : FunSpec() {
         withClue("Should be limited") {
             logErrors()
             map { it.status } shouldContain TooManyRequests
+            flatMap { it.headers.names() } shouldContainAll listOf("X-RateLimit-Limit", "X-RateLimit-Measured-by", "X-RateLimit-Reset")
         }
     }