Update doctests test driver

templates/haskell/core/tests/doctests.hs

@@ -1,12 +1,28 @@
 {-# LANGUAGE Unsafe #-}
 
+-- |
+-- Copyright: 2017-2020 Oleg Grenrus, 2020- Max Ulidtko
+-- License: BSD-3-Clause
+--
+-- Test-suite driver, adapted from
+-- [cabal-doctest](https://hackage.haskell.org/package/cabal-doctest).
 module Main (main) where
 
+import safe "base" Control.Category ((.))
+import safe "base" Data.Foldable (fold)
 import safe "base" Data.Function (($))
+import safe "base" Data.Functor (fmap)
 import safe "base" Data.Semigroup ((<>))
-import safe "base" System.IO (IO)
+import safe "base" Data.Traversable (for)
+import safe "base" System.IO (IO, print, putStrLn)
 import "doctest" Test.DocTest (doctest)
-import "this" Build_doctests (flags, module_sources, pkgs)
+import "this" Build_doctests (Component (Component), components)
 
+-- | The doctest entry point.
+--
+-- @since 0.0.1
 main :: IO ()
-main = doctest $ flags <> pkgs <> module_sources
+main = fmap fold . for components $ \(Component name flags pkgs sources) -> do
+  print name
+  putStrLn "----------------------------------------"
+  doctest $ flags <> pkgs <> sources

templates/haskell/core/{{project.name}}.cabal

@@ -238,6 +238,10 @@ test-suite doctests
       -- to ensure it gets built before this test-suite, even though the package
       -- appears to be unused.
       -Wno-unused-packages
+  -- NB: Adjust this to contain any components that may have doctests (including
+  --     executables).
+  x-doctest-components:
+    lib
   -- TODO: The sections below here are necessary because we don’t have control
   --       over the generated `Build_doctests.hs` file. So we have to silence
   --       all of its warnings one way or another.