Throw exception if decisions is empty

src/main/kotlin/io/github/flecomte/AccessKontrol.kt

@@ -27,9 +27,13 @@ abstract class AccessKontrol {
 
     /**
      * A helper to convert a list of subject into one response
+     *
+     * @throws [NoDecision] if the list of responses is empty
      */
     protected fun <S : List<T>, T> canAll(items: S, action: (T) -> AccessResponse): AccessResponses = items
-        .map { action(it) }.let { responses ->
+        .ifEmpty { throw NoDecision() }
+        .map { action(it) }
+        .let { responses ->
             if (responses.any { it is DeniedResponse }) {
                 DeniedResponses(responses)
             } else {
@@ -50,9 +54,12 @@ typealias AccessResponses = List<AccessResponse>
 /**
  * Check all responses and return DENIED if one is DENIED
  *
- * If the list of responses is empty, return GRANTED
+ * @throws [NoDecision] if the list of responses is empty
  */
-fun AccessResponses.getFirstDecisionResponse(): AccessResponse = this.firstOrNull { it.decision == AccessDecision.DENIED } ?: this.first { it.decision == AccessDecision.GRANTED }
+fun AccessResponses.getFirstDecisionResponse(): AccessResponse {
+    ifEmpty { throw NoDecision() }
+    return firstOrNull { it.decision == AccessDecision.DENIED } ?: first()
+}
 
 /**
  * Throw an Exception if one response is DENIED
@@ -62,8 +69,8 @@ fun AccessResponses.assert() {
         throw AccessDeniedException(this)
     }
 }
-val AccessResponses.grantedResponses get(): AccessResponses = this.filterIsInstance<GrantedResponse>()
+val AccessResponses.grantedResponses get(): List<GrantedResponse> = this.filterIsInstance<GrantedResponse>()
-val AccessResponses.deniedResponses get(): AccessResponses = this.filterIsInstance<DeniedResponse>()
+val AccessResponses.deniedResponses get(): List<DeniedResponse> = this.filterIsInstance<DeniedResponse>()
 
 /**
  * Convert responses as boolean
@@ -78,6 +85,9 @@ class AccessDeniedException(val accessResponses: AccessResponses) : Throwable(ac
      */
     fun first(): AccessResponse = accessResponses.deniedResponses.first()
 
+    val deniedResponses: List<DeniedResponse>
+        get() = this.accessResponses.deniedResponses
+
     /**
      * Check if the error code is present into the responses
      */
@@ -97,12 +107,12 @@ class AccessDeniedException(val accessResponses: AccessResponses) : Throwable(ac
      */
     fun getMessages(): List<String> = accessResponses
         .deniedResponses
-        .map { it.message!! }
+        .map { it.message }
 
     /**
      * Get the first message
      */
-    fun getFirstMessage(): String? = accessResponses
+    fun getFirstMessage(): String = accessResponses
         .deniedResponses
         .first()
         .message
@@ -116,8 +126,8 @@ class AccessDeniedException(val accessResponses: AccessResponses) : Throwable(ac
 sealed class AccessResponse(
     val decision: AccessDecision,
     val accessControl: AccessKontrol,
-    val message: String?,
+    open val message: String?,
-    val code: String?
+    open val code: String?
 ) {
     /**
      * Convert response as boolean
@@ -142,8 +152,8 @@ open class GrantedResponse(
 
 open class DeniedResponse(
     accessControl: AccessKontrol,
-    message: String,
+    override val message: String,
-    code: String
+    override val code: String
 ) : AccessResponse(AccessDecision.DENIED, accessControl, message, code)
 
 class GrantedResponses(
@@ -159,7 +169,9 @@ class DeniedResponses(
     accessResponses: List<AccessResponse>
 ) : AccessResponses by accessResponses,
     DeniedResponse(
-        accessResponses.deniedResponses.first().accessControl,
+        accessResponses.deniedResponses.firstOrNull()?.accessControl ?: error("DeniedResponses cannot be empty"),
-        accessResponses.deniedResponses.firstOrNull()?.message ?: error("DeniedResponses cannot be empty"),
+        accessResponses.deniedResponses.first().message,
-        accessResponses.deniedResponses.firstOrNull()?.code ?: error("DeniedResponses cannot be empty")
+        accessResponses.deniedResponses.first().code
     )
+
+class NoDecision : RuntimeException("No decision has been taken")

src/test/kotlin/io/github/flecomte/AccessKontrolTest.kt

@@ -59,6 +59,14 @@ class AccessKontrolTest {
         }
     }
 
+    @Test
+    fun `test empty canAllGranted`() {
+        assertThrows(NoDecision::class.java) {
+            AccessControlSample()
+                .canView(listOf(), User(""))
+        }
+    }
+
     @Test
     fun `test CanAllDenied`() {
         AccessControlSample().run {
@@ -98,6 +106,7 @@ class AccessKontrolTest {
             assertEquals(null, getErrorCode("notExists")?.code)
             assertEquals("KO2", getMessages().last())
             assertEquals("KO", getFirstMessage())
+            assertEquals("ko", deniedResponses.firstOrNull()?.code)
         }
     }
 
@@ -128,6 +137,14 @@ class AccessKontrolTest {
             }
     }
 
+    @Test
+    fun `test getFirstDecisionResponse on empty`() {
+        assertThrows(NoDecision::class.java) {
+            listOf<AccessResponse>()
+                .getFirstDecisionResponse()
+        }
+    }
+
     @Test
     fun `GrantedResponse instantiation test`() {
         assertEquals(AccessDecision.GRANTED, GrantedResponse(AccessControlSample()).decision)