Stop early when coverage has been assured to be satisfied

This also fixes an issue where tests would give false negatives when
coverage was below the specified percentages.

What was happening was that we would check if the result was verified -
it would say no and thus give us an incorrect error message:

"Insufficent coverage."

hedgehog/src/Hedgehog/Internal/Runner.hs

@@ -168,9 +168,7 @@ checkReport cfg size0 seed0 test0 updateUI =
       -- If the user wants a statistically significant result, this function
       -- will run a confidence check. Otherwise, it will default to checking
       -- the percentage of encountered labels
-      maybe
-        (coverageSuccess count coverage)
-        (\c -> confidenceSuccess count c coverage) confidence
+      maybe False (\c -> confidenceSuccess count c coverage) confidence
 
     failureVerified count coverage =
       -- Will be true if we can statistically verify that our coverage was
@@ -191,6 +189,10 @@ checkReport cfg size0 seed0 test0 updateUI =
         -- size has reached limit, reset to 0
         loop tests discards 0 seed coverage0
 
+      else if tests > 0 && successVerified tests coverage0 then
+        -- tests have been verified to reach coverage for all labels
+        pure $ Report tests discards coverage0 OK
+
       else if failureVerified tests coverage0 then
         -- tests have been verified to not reach coverage for at least one label
         pure . Report tests discards coverage0 . Failed $
@@ -206,7 +208,7 @@ checkReport cfg size0 seed0 test0 updateUI =
 
       else if tests >= fromIntegral (propertyTestLimit cfg) then
         -- we've hit the test limit
-        if successVerified tests coverage0 then
+        if coverageSuccess tests coverage0 then
           -- all classifiers satisfied, test was successful
           pure $ Report tests discards coverage0 OK