Changed the allow parameter to also take a string

lib/build.gradle.kts

@@ -108,7 +108,7 @@ tasks {
         archiveBaseName.set(rootProject.name)
     }
 
-    "sonarqube" {
+    "sonar" {
         dependsOn(koverReport)
     }
 }

lib/detekt-baseline.xml

@@ -7,6 +7,6 @@
     <ID>MagicNumber:UrlEncoder.kt$UrlEncoder$16</ID>
     <ID>MagicNumber:UrlEncoder.kt$UrlEncoder$3</ID>
     <ID>MagicNumber:UrlEncoder.kt$UrlEncoder$4</ID>
-    <ID>NestedBlockDepth:UrlEncoder.kt$UrlEncoder$@JvmStatic fun encode(source: String, vararg allow: Char): String</ID>
+    <ID>NestedBlockDepth:UrlEncoder.kt$UrlEncoder$@JvmStatic fun encode(source: String, allow: String): String</ID>
   </CurrentIssues>
 </SmellBaseline>

lib/src/main/kotlin/net/thauvin/erik/urlencoder/UrlEncoder.kt

@@ -83,7 +83,7 @@ object UrlEncoder {
             ch = source[i]
             if (ch == '%') {
                 if (out == null) {
-                    out = StringBuilder(source.length)
+                    out = StringBuilder(length)
                     out.append(source, 0, i)
                 }
                 if (bytesBuffer == null) {
@@ -125,7 +125,7 @@ object UrlEncoder {
      * encoding. Letters, numbers, unreserved (`_-!.~'()*`) and allowed characters are left intact.
      */
     @JvmStatic
-    fun encode(source: String, vararg allow: Char): String {
+    fun encode(source: String, allow: String): String {
         if (source.isBlank()) {
             return source
         }
@@ -135,7 +135,7 @@ object UrlEncoder {
         var i = 0
         while (i < source.length) {
             ch = source[i]
-            if (ch.isUnreserved() || allow.contains(ch)) {
+            if (ch.isUnreserved() || allow.indexOf(ch) != -1) {
                 out?.append(ch)
                 i++
             } else {
@@ -165,4 +165,13 @@ object UrlEncoder {
 
         return out?.toString() ?: source
     }
+
+    /**
+     * Transforms a provided [String] object into a new string, containing only valid URL characters in the UTF-8
+     * encoding. Letters, numbers, unreserved (`_-!.~'()*`) and allowed characters are left intact.
+     */
+    @JvmStatic
+    fun encode(source: String, vararg allow: Char): String {
+        return encode(source, String(allow))
+    }
 }

lib/src/test/kotlin/net/thauvin/erik/urlencoder/UrlEncoderTest.kt

@@ -23,6 +23,7 @@ import org.junit.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFailsWith
 import kotlin.test.assertSame
+import kotlin.test.assertTrue
 
 
 class UrlEncoderTest {
@@ -53,10 +54,13 @@ class UrlEncoderTest {
     fun testEncode() {
         assertEquals("", encode(""))
         assertSame(same, encode(same))
+        assertSame(same, encode(same, ""))
+        assertTrue(encode("").isEmpty())
         validMap.forEach {
             assertEquals(it.value, encode(it.key))
         }
         assertEquals("?test=a%20test", encode("?test=a test", '=', '?'))
+        assertEquals("?test=a%20test", encode("?test=a test", "=?"))
         assertEquals("aaa", encode("aaa", 'a'))
     }
 }