Initial diamond text support in test suite

exercises/diamond/.meta/hints.md

@@ -0,0 +1,39 @@
+## Hints
+
+You need to implement the `diamond` function which prints a diamond starting at
+`A` with the given character at its widest points. You can use the provided
+signature if you are unsure about the types, but don't let it restrict your
+creativity:
+
+```haskell
+diamond :: Char -> Maybe [String]
+```
+
+This exercise works with textual data. For historical reasons, Haskell's
+`String` type is synonymous with `[Char]`, a list of characters. For more
+efficient handling of textual data, the `Text` type can be used.
+
+As an optional extension to this exercise, you can
+
+- Read about [string types](https://haskell-lang.org/tutorial/string-types) in
+  Haskell.
+- Add `- text` to your list of dependencies in package.yaml.
+- Import `Data.Text` in [the following
+  way](https://hackernoon.com/4-steps-to-a-better-imports-list-in-haskell-43a3d868273c):
+
+```haskell
+import qualified Data.Text as T
+import           Data.Text (Text)
+```
+
+- You can now write e.g. `diamond :: Char -> Maybe [Text]` and refer to
+  `Data.Text` combinators as e.g. `T.pack`,
+- Look up the documentation for
+  [`Data.Text`](https://hackage.haskell.org/package/text/docs/Data-Text.html),
+- You can then replace all occurrences of `String` with `Text` in Diamond.hs:
+
+```haskell
+diamond :: Char -> Maybe [Text]
+```
+
+This part is entirely optional.

exercises/diamond/README.md

@@ -52,6 +52,47 @@ E·······E
 ····A····
 ```
 
+## Hints
+
+You need to implement the `diamond` function which prints a diamond starting at
+`A` with the given character at its widest points. You can use the provided
+signature if you are unsure about the types, but don't let it restrict your
+creativity:
+
+```haskell
+diamond :: Char -> Maybe [String]
+```
+
+This exercise works with textual data. For historical reasons, Haskell's
+`String` type is synonymous with `[Char]`, a list of characters. For more
+efficient handling of textual data, the `Text` type can be used.
+
+As an optional extension to this exercise, you can
+
+- Read about [string types](https://haskell-lang.org/tutorial/string-types) in
+  Haskell.
+- Add `- text` to your list of dependencies in package.yaml.
+- Import `Data.Text` in [the following
+  way](https://hackernoon.com/4-steps-to-a-better-imports-list-in-haskell-43a3d868273c):
+
+```haskell
+import qualified Data.Text as T
+import           Data.Text (Text)
+```
+
+- You can now write e.g. `diamond :: Char -> Maybe [Text]` and refer to
+  `Data.Text` combinators as e.g. `T.pack`,
+- Look up the documentation for
+  [`Data.Text`](https://hackage.haskell.org/package/text/docs/Data-Text.html),
+- You can then replace all occurrences of `String` with `Text` in Diamond.hs:
+
+```haskell
+diamond :: Char -> Maybe [Text]
+```
+
+This part is entirely optional.
+
+
 
 ## Getting Started
 

exercises/diamond/examples/success-standard/package.yaml

@@ -15,3 +15,5 @@ tests:
       - diamond
       - hspec
       - QuickCheck
+      - text
+      - string-conversions

exercises/diamond/package.yaml

@@ -1,5 +1,5 @@
 name: diamond
-version: 1.1.0.5
+version: 1.1.0.6
 
 dependencies:
   - base
@@ -20,3 +20,5 @@ tests:
       - diamond
       - hspec
       - QuickCheck
+      - text
+      - string-conversions

exercises/diamond/test/Tests.hs

@@ -1,14 +1,17 @@
 {-# LANGUAGE RecordWildCards #-}
-
-import Data.Char         (isLetter, isPrint, isSpace)
-import Data.Foldable     (for_)
-import Data.List         (isSuffixOf)
-import Data.Maybe        (isJust, isNothing)
-import Test.Hspec        (Spec, describe, it, shouldBe)
-import Test.Hspec.Runner (configFastFail, defaultConfig, hspecWith)
-import Test.QuickCheck   (arbitraryASCIIChar, conjoin, counterexample,
-                          discard, elements, forAll, forAllShrink, Gen,
-                          Property, suchThat, Testable, (===))
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE FlexibleInstances #-}
+
+import Data.Char               (isLetter, isPrint, isSpace)
+import Data.Foldable           (for_)
+import Data.List               (isSuffixOf)
+import Data.Maybe              (isJust, isNothing)
+import Data.String.Conversions (convertString)
+import Test.Hspec              (Spec, describe, it, shouldBe)
+import Test.Hspec.Runner       (configFastFail, defaultConfig, hspecWith)
+import Test.QuickCheck         (arbitraryASCIIChar, conjoin, counterexample,
+                                discard, elements, forAll, forAllShrink, Gen,
+                                Property, suchThat, Testable, (===))
 
 import Diamond (diamond)
 
@@ -50,7 +53,7 @@ specs = describe "diamond" $ do
   where
     test Case{..} = it description assertion
       where
-        assertion = diamond input `shouldBe` Just expected
+        assertion = (fmap . fmap) convertString (diamond input) `shouldBe` Just expected
 
 
 data Case = Case { description :: String
@@ -151,7 +154,7 @@ genAlphaChar :: Gen Char
 genAlphaChar = elements ['A'..'Z']
 
 genDiamond :: Gen (Maybe [String])
-genDiamond = diamond <$> genAlphaChar
+genDiamond = (fmap . fmap . fmap) convertString $ diamond <$> genAlphaChar
 
 forAllDiamond :: Testable prop => ([String] -> prop) -> Property
 forAllDiamond p = forAll genDiamond $ maybe discard p