Fix SelectorHelpers.computeAbsoluteUrl

part of #1117

app/shared/app-data/src/commonMain/kotlin/domain/mediasource/web/format/SelectorFormat.kt

@@ -10,6 +10,8 @@
 package me.him188.ani.app.domain.mediasource.web.format
 
 import androidx.compose.runtime.Immutable
+import io.ktor.http.URLBuilder
+import io.ktor.http.appendPathSegments
 import kotlinx.serialization.Serializable
 import kotlin.jvm.JvmInline
 
@@ -48,15 +50,8 @@ fun Regex.Companion.parseOrNull(regex: String): Regex? {
 
 object SelectorHelpers {
     fun computeAbsoluteUrl(baseUrl: String, relativeUrl: String): String {
-        @Suppress("NAME_SHADOWING")
-        var baseUrl = baseUrl
-        if (baseUrl.endsWith('/')) {
-            baseUrl = baseUrl.dropLast(1)
-        }
-        return when {
-            relativeUrl.startsWith("http") -> relativeUrl
-            relativeUrl.startsWith('/') -> baseUrl + relativeUrl
-            else -> "$baseUrl/$relativeUrl"
-        }
+        return URLBuilder(baseUrl)
+            .appendPathSegments(relativeUrl, encodeSlash = false)
+            .buildString()
     }
 }

app/shared/app-data/src/commonTest/kotlin/domain/mediasource/web/format/SelectorHelpersTest.kt

@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2024 OpenAni and contributors.
+ *
+ * 此源代码的使用受 GNU AFFERO GENERAL PUBLIC LICENSE version 3 许可证的约束, 可以在以下链接找到该许可证.
+ * Use of this source code is governed by the GNU AGPLv3 license, which can be found at the following link.
+ *
+ * https://github.com/open-ani/ani/blob/main/LICENSE
+ */
+
+package me.him188.ani.app.domain.mediasource.web.format
+
+import me.him188.ani.test.TestContainer
+import me.him188.ani.test.TestFactory
+import me.him188.ani.test.runDynamicTests
+import kotlin.test.assertEquals
+
+/**
+ * @see SelectorHelpers.computeAbsoluteUrl
+ */
+@TestContainer
+class ComputeAbsoluteUrlTest {
+    @TestFactory
+    fun computeAbsoluteUrlTest() = runDynamicTests {
+        fun case(
+            expected: String,
+            baseUrl: String,
+            relativeUrl: String,
+        ) = add("$baseUrl + $relativeUrl = $expected") {
+            assertEquals(
+                expected,
+                SelectorHelpers.computeAbsoluteUrl(baseUrl, relativeUrl),
+            )
+        }
+
+        case(
+            "https://example.com/relative",
+            "https://example.com", "relative",
+        )
+
+        case(
+            "https://example.com/relative",
+            "https://example.com", "/relative",
+        )
+
+        case(
+            "https://example.com/relative",
+            "https://example.com/", "/relative",
+        )
+
+        case(
+            "https://example.com/relative/",
+            "https://example.com/", "/relative/",
+        )
+
+        case(
+            "https://example.com/relative/foo",
+            "https://example.com/", "/relative/foo",
+        )
+
+        case(
+            "https://example.com/relative/foo/../bar",
+            "https://example.com/", "/relative/foo/../bar",
+        )
+
+        case(
+            "https://example.com/",
+            "https://example.com/", "",
+        )
+
+        case(
+            "http://localhost/",
+            "", "",
+        )
+
+        case(
+            "http://localhost/test",
+            "", "/test",
+        )
+
+        case(
+            "http://localhost/test",
+            "", "test",
+        )
+    }
+}