misc: Improve the test coverage of the OsmoNetwork

Get the >>#parameterName/>>#spec out of the uncovered methods, this
is done by just finding the right classes and calling the selectors.
Add some simple tests for a MessageBuffer method that was not covered
yet.

Tests.st

@@ -236,6 +236,29 @@ TestCase subclass: MessageBufferTest [
         self assert: msg size = 0.
         self assert: msg toByteArray = #() asByteArray.
     ]
+
+    testPrependByteArray [
+        | msg |
+        msg := MessageBuffer new.
+        msg putByteArray: #(3 4 5) asByteArray.
+        msg prependByteArray: #(1 2) asByteArray.
+        self assert: msg toByteArray = #(1 2 3 4 5) asByteArray.
+
+        msg := MessageBuffer new.
+        msg prependByteArray: #(1 2) asByteArray.
+        msg putByteArray: #(3 4 5) asByteArray.
+        self assert: msg toByteArray = #(1 2 3 4 5) asByteArray.
+
+        msg := MessageBuffer new.
+        msg prependByteArray: #(1 2) asByteArray.
+        self assert: msg toByteArray = #(1 2) asByteArray.
+    ]
+
+    testIdentity [
+        | msg |
+        msg := MessageBuffer new.
+        self assert: msg toMessage == msg.
+    ]
 ]
 
 TestCase subclass: M2UAMSGTests [

isup/ISUPTests.st

@@ -66,4 +66,13 @@ TestCase subclass: ISUPGeneratedTest [
     testClassCount [
         self assert: ISUPMessage allSubclasses size = 46.
     ]
+
+    testSpecParmameterNameSmokeTest [
+        MSGField allSubclassesDo: [:class |
+            class category = 'OsmoNetwork-ISUP'
+                ifTrue: [
+                    self
+                        assert: class parameterName isString;
+                        assert: class spec isString]].
+    ]
 ]