callagent: Add testcase for the allocation FSM of an endpoint

Verify the legal transitions and the non-legal ones (exceptions
are thrown in that case).

callagent/MGCPEndpoint.st

@@ -91,7 +91,7 @@ Object subclass: MGCPEndpoint [
     free [
         <category: 'allocation'>
         self requireState: self class stateUsed.
-        state := self class stateUsed.
+        state := self class stateUnused.
     ]
 
     tryBlock [

callagent/Tests.st

@@ -185,3 +185,49 @@ TestCase subclass: MGCPTransactionTest [
         self dropAgent stop.
     ]
 ]
+
+TestCase subclass: MGCPEndpointAllocTest [
+    testStateTransition [
+        | trunk endp |
+
+        trunk := MGCPVirtualTrunk createWithDest: '127.0.0.1' numberPorts: 32.
+        endp := trunk endpointAt: 1.
+
+        "Initial..."
+        self assert: endp isUnused.
+
+        "Reserve..."
+        endp reserve.
+        self assert: endp isReserved.
+        self should: [endp reserve] raise: Error.
+        self should: [endp free] raise: Error.
+        self should: [endp unblock] raise: Error.
+        self deny: endp tryBlock.
+
+        "Move to used..."
+        endp used.
+        self assert: endp isUsed.
+        self should: [endp reserve] raise: Error.
+        self should: [endp used] raise: Error.
+        self should: [endp unblock] raise: Error.
+        self deny: endp tryBlock.
+
+        "Move to free..."
+        endp free.
+        self assert: endp isUnused.
+        self should: [endp used] raise: Error.
+        self should: [endp unblock] raise: Error.
+        self assert: endp tryBlock.
+
+        "Now try to block it..."
+        self assert: endp isBlocked.
+        self should: [endp reserve] raise: Error.
+        self should: [endp free] raise: Error.
+        self should: [endp used] raise: Error.
+        self deny: endp tryBlock.
+
+        "Now unblock and restore"
+        endp unblock.
+        self assert: endp isUnused.
+    ]
+]

package.xml

@@ -16,6 +16,7 @@
     <test>
         <sunit>Osmo.MGCPGrammarTest</sunit>
         <sunit>Osmo.MGCPCommandTest</sunit>
+        <sunit>Osmo.MGCPEndpointAllocTest</sunit>
         <sunit>Osmo.MGCPTransactionTest</sunit>
         <filein>grammar/MGCPGrammarTest.st</filein>
         <filein>callagent/Tests.st</filein>