feat(client): add HttpRequest#url() method

Author: stainless-app[bot]

LICENSE

@@ -186,7 +186,7 @@
       same "printed page" as the copyright notice for easier
       identification within third-party archives.
 
-   Copyright 2025 Lithic
+   Copyright 2026 Lithic
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.

lithic-java-core/src/main/kotlin/com/lithic/api/core/http/HttpRequest.kt

@@ -2,6 +2,7 @@ package com.lithic.api.core.http
 
 import com.lithic.api.core.checkRequired
 import com.lithic.api.core.toImmutable
+import java.net.URLEncoder
 
 class HttpRequest
 private constructor(
@@ -13,6 +14,35 @@ private constructor(
     @get:JvmName("body") val body: HttpRequestBody?,
 ) {
 
+    fun url(): String = buildString {
+        append(baseUrl)
+
+        pathSegments.forEach { segment ->
+            if (!endsWith("/")) {
+                append("/")
+            }
+            append(URLEncoder.encode(segment, "UTF-8"))
+        }
+
+        if (queryParams.isEmpty()) {
+            return@buildString
+        }
+
+        append("?")
+        var isFirst = true
+        queryParams.keys().forEach { key ->
+            queryParams.values(key).forEach { value ->
+                if (!isFirst) {
+                    append("&")
+                }
+                append(URLEncoder.encode(key, "UTF-8"))
+                append("=")
+                append(URLEncoder.encode(value, "UTF-8"))
+                isFirst = false
+            }
+        }
+    }
+
     fun toBuilder(): Builder = Builder().from(this)
 
     override fun toString(): String =

lithic-java-core/src/test/kotlin/com/lithic/api/core/http/HttpRequestTest.kt

@@ -0,0 +1,110 @@
+package com.lithic.api.core.http
+
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.jupiter.params.ParameterizedTest
+import org.junit.jupiter.params.provider.EnumSource
+
+internal class HttpRequestTest {
+
+    enum class UrlTestCase(val request: HttpRequest, val expectedUrl: String) {
+        BASE_URL_ONLY(
+            HttpRequest.builder().method(HttpMethod.GET).baseUrl("https://api.example.com").build(),
+            expectedUrl = "https://api.example.com",
+        ),
+        BASE_URL_WITH_TRAILING_SLASH(
+            HttpRequest.builder()
+                .method(HttpMethod.GET)
+                .baseUrl("https://api.example.com/")
+                .build(),
+            expectedUrl = "https://api.example.com/",
+        ),
+        SINGLE_PATH_SEGMENT(
+            HttpRequest.builder()
+                .method(HttpMethod.GET)
+                .baseUrl("https://api.example.com")
+                .addPathSegment("users")
+                .build(),
+            expectedUrl = "https://api.example.com/users",
+        ),
+        MULTIPLE_PATH_SEGMENTS(
+            HttpRequest.builder()
+                .method(HttpMethod.GET)
+                .baseUrl("https://api.example.com")
+                .addPathSegments("users", "123", "profile")
+                .build(),
+            expectedUrl = "https://api.example.com/users/123/profile",
+        ),
+        PATH_SEGMENT_WITH_SPECIAL_CHARS(
+            HttpRequest.builder()
+                .method(HttpMethod.GET)
+                .baseUrl("https://api.example.com")
+                .addPathSegment("user name")
+                .build(),
+            expectedUrl = "https://api.example.com/user+name",
+        ),
+        SINGLE_QUERY_PARAM(
+            HttpRequest.builder()
+                .method(HttpMethod.GET)
+                .baseUrl("https://api.example.com")
+                .addPathSegment("users")
+                .putQueryParam("limit", "10")
+                .build(),
+            expectedUrl = "https://api.example.com/users?limit=10",
+        ),
+        MULTIPLE_QUERY_PARAMS(
+            HttpRequest.builder()
+                .method(HttpMethod.GET)
+                .baseUrl("https://api.example.com")
+                .addPathSegment("users")
+                .putQueryParam("limit", "10")
+                .putQueryParam("offset", "20")
+                .build(),
+            expectedUrl = "https://api.example.com/users?limit=10&offset=20",
+        ),
+        QUERY_PARAM_WITH_SPECIAL_CHARS(
+            HttpRequest.builder()
+                .method(HttpMethod.GET)
+                .baseUrl("https://api.example.com")
+                .addPathSegment("search")
+                .putQueryParam("q", "hello world")
+                .build(),
+            expectedUrl = "https://api.example.com/search?q=hello+world",
+        ),
+        MULTIPLE_VALUES_SAME_PARAM(
+            HttpRequest.builder()
+                .method(HttpMethod.GET)
+                .baseUrl("https://api.example.com")
+                .addPathSegment("users")
+                .putQueryParams("tags", listOf("admin", "user"))
+                .build(),
+            expectedUrl = "https://api.example.com/users?tags=admin&tags=user",
+        ),
+        BASE_URL_WITH_TRAILING_SLASH_AND_PATH(
+            HttpRequest.builder()
+                .method(HttpMethod.GET)
+                .baseUrl("https://api.example.com/")
+                .addPathSegment("users")
+                .build(),
+            expectedUrl = "https://api.example.com/users",
+        ),
+        COMPLEX_URL(
+            HttpRequest.builder()
+                .method(HttpMethod.POST)
+                .baseUrl("https://api.example.com")
+                .addPathSegments("v1", "users", "123")
+                .putQueryParams("include", listOf("profile", "settings"))
+                .putQueryParam("format", "json")
+                .build(),
+            expectedUrl =
+                "https://api.example.com/v1/users/123?include=profile&include=settings&format=json",
+        ),
+    }
+
+    @ParameterizedTest
+    @EnumSource
+    fun url(testCase: UrlTestCase) {
+        val actualUrl = testCase.request.url()
+
+        assertThat(actualUrl).isEqualTo(testCase.expectedUrl)
+    }
+}