🐛 improve key extraction and decoding logic for better clarity and performance

Author: techouse

.gitignore

@@ -16,6 +16,9 @@ out/
 !**/src/main/**/out/
 !**/src/test/**/out/
 
+## Gradle ###
+local.properties
+
 ### Kotlin ###
 .kotlin
 
@@ -42,4 +45,4 @@ bin/
 .vscode/
 
 ### Mac OS ###
-.DS_Store
+.DS_Store

qs-kotlin/src/main/kotlin/io/github/techouse/qskotlin/internal/Decoder.kt

@@ -113,7 +113,7 @@ internal object Decoder {
                 key = options.getDecoder(part, charset).toString()
                 value = if (options.strictNullHandling) null else ""
             } else {
-                key = options.getDecoder(part.substring(0, pos), charset).toString()
+                key = options.getDecoder(part.take(pos), charset).toString()
                 value =
                     Utils.apply<Any?>(
                         parseListValue(
@@ -210,7 +210,7 @@ internal object Decoder {
                     } else cleanRoot
 
                 val index: Int? =
-                    if (decodedRoot.isNotEmpty() && decodedRoot.all(Char::isDigit))
+                    if (decodedRoot.isNotEmpty() && decodedRoot.toIntOrNull() != null)
                         decodedRoot.toInt()
                     else null
 
@@ -312,7 +312,7 @@ internal object Decoder {
         val segments = ArrayList<String>(key.count { it == '[' } + 1)
 
         val first = key.indexOf('[')
-        val parent = if (first >= 0) key.substring(0, first) else key
+        val parent = if (first >= 0) key.take(first) else key
         if (parent.isNotEmpty()) segments.add(parent)
 
         var open = first

qs-kotlin/src/test/kotlin/io/github/techouse/qskotlin/unit/DecodeSpec.kt

@@ -523,9 +523,9 @@ class DecodeSpec :
                 decode("a[0]=b", DecodeOptions(listLimit = 0)) shouldBe mapOf("a" to listOf("b"))
 
                 decode("a[-1]=b", DecodeOptions(listLimit = -1)) shouldBe
-                    mapOf("a" to mapOf("-1" to "b"))
+                    mapOf("a" to mapOf(-1 to "b"))
                 decode("a[-1]=b", DecodeOptions(listLimit = 0)) shouldBe
-                    mapOf("a" to mapOf("-1" to "b"))
+                    mapOf("a" to mapOf(-1 to "b"))
 
                 decode("a[0]=b&a[1]=c", DecodeOptions(listLimit = -1)) shouldBe
                     mapOf("a" to mapOf(0 to "b", 1 to "c"))