Add more reject-unconstrained tests

Author: philderbeast

cabal-install/tests/UnitTests/Distribution/Solver/Modular/Solver.hs

@@ -243,15 +243,32 @@ tests =
               solverFailure (isInfixOf "rejecting: base-1 (constraint from non-reinstallable package requires >=4.22)")
       ]
   , testGroup
+      -- reject-unconstrained-dependencies=all requires all non-goals to be
+      -- version constrained. Goals don't need constraints and flag constraints
+      -- are not enough.
       "reject-unconstrained"
       [ runTest $
           onlyConstrained $
             mkTest db12 "missing syb" ["E"] $
               solverFailure (isInfixOf "not a user-provided goal")
+      , runTest $
+            onlyConstrained $
+              mkTest db12 "all goals, no other dependencies" ["base", "E", "syb"] $
+                solverSuccess [("E", 1), ("syb", 2)]
       , runTest $
           onlyConstrained $
-            mkTest db12 "all goals" ["E", "syb"] $
-              solverSuccess [("E", 1), ("syb", 2)]
+            mkTest db12 "non-goal dependencies are unconstrained" ["E", "syb"] $
+              solverFailure (isInfixOf "not a user-provided goal")
+      , runTest $
+          constraints [ExFlagConstraint (ScopeAnyQualifier "base") "flag" True] $
+            onlyConstrained $
+              mkTest db12 "non-goal dependencies are only flag-constrained" ["E", "syb"] $
+                solverFailure (isInfixOf "not a user-provided goal")
+      , runTest $
+          constraints [ExVersionConstraint (ScopeAnyQualifier "base") (V.thisVersion (V.mkVersion [4]))] $
+            onlyConstrained $
+              mkTest db12 "non-goal dependencies are version-constrained" ["E", "syb"] $
+                solverSuccess [("E", 1), ("syb", 2)]
       , runTest $
           onlyConstrained $
             mkTest db17 "backtracking" ["A", "B"] $