implement first actual test case with hspec and run it

Hash2Pub/shell.nix

@@ -1 +1 @@
-(import ./. {}).shell
+(import ./default.nix {}).shell

Hash2Pub/src/Hash2Pub/FediChord.hs

@@ -11,6 +11,7 @@ Modernised EpiChord + k-choices load balancing
 
 module Hash2Pub.FediChord (
     NodeID -- abstract, but newtype constructors cannot be hidden
+  , getNodeID
   , mkNodeID
   , NodeState (..)
   , CacheEntry

Hash2Pub/test/MyLibTest.hs

@@ -1,6 +1,13 @@
 module Main (main) where
 
-import qualified Hash2Pub.FediChord as FC
+import Test.Hspec
+
+import Hash2Pub.FediChord
 
 main :: IO ()
-main = putStrLn "Test suite not yet implemented."
+main = hspec $ do
+    describe "NodeID" $ do
+        it "can store a numeral ID" $ do
+            getNodeID (mkNodeID 2342) `shouldBe` 2342
+        it "computes ID values within the modular bounds" $ do
+            getNodeID ((maxBound :: NodeID) + mkNodeID 2) < getNodeID (maxBound :: NodeID) `shouldBe` True