Phase 4: Recipe references + all 4 example file validation

- Fix pRecipeRef to include ./ prefix in stored path
- Add recipe reference test
- Add parse-validation tests for all 4 example .cook files
  (EasyPancakes, FriedRice, CoffeeSouffle, OlivierSalad)
- All 24 tests passing, all examples parse without error

src/Roux/Parser.hs

@@ -131,11 +131,12 @@ pLineBreak = do
 pRecipeRef :: Parser StepItem
 pRecipeRef = do
     _ <- P.char '@'
+    -- Consume @ and store ./ as part of the path
     _ <- P.char '.'
     _ <- P.char '/'
     path <- P.many (P.noneOf "{(\n\\")
     mqty <- P.optionMaybe (P.between (P.char '{') (P.char '}') pQuantityBody)
-    return (StepRecipeRef (RecipeRef path (join mqty)))
+    return (StepRecipeRef (RecipeRef ("./" <> path) (join mqty)))
 
 -- | Ingredient: @name{quantity%unit}(preparation)
 pIngredient :: Parser StepItem

test/Roux/ParserSpec.hs

@@ -2,6 +2,7 @@ module Roux.ParserSpec (spec) where
 
 import Data.List.NonEmpty (NonEmpty ((:|)))
 import qualified Data.List.NonEmpty as NE
+import qualified Data.Text.IO as TIO
 import Test.Hspec (Spec, describe, expectationFailure, it, shouldBe)
 
 import Roux.Parser (parseCookFile)
@@ -369,3 +370,44 @@ spec = do
                         _ ->
                             expectationFailure
                                 ("expected SecStep as third body item, got body=" <> show body)
+
+    describe "Recipe references" $ do
+        it "parses a recipe reference" $ do
+            let input = "Pour over with @./sauces/Hollandaise{150%g}."
+            case parseCookFile input of
+                Left err -> expectationFailure ("parse failed: " <> err)
+                Right recipe -> do
+                    let items = stepItems recipe
+                    let expected =
+                            [ StepText "Pour over with "
+                            , StepRecipeRef (RecipeRef "./sauces/Hollandaise" (Just (Quantity 150 (Just "g") False)))
+                            , StepText "."
+                            ]
+                    items `shouldBe` expected
+
+    describe "Full recipe files" $ do
+        let readExample name = do
+                content <- TIO.readFile ("cooklang-examples/" <> name <> ".cook")
+                case parseCookFile content of
+                    Left err -> expectationFailure (name <> ": " <> err)
+                    Right _ -> pure ()
+
+        it "EasyPancakes parses without error" $ do
+            readExample "EasyPancakes"
+
+        it "FriedRice parses without error" $ do
+            readExample "FriedRice"
+
+        it "CoffeeSouffle parses without error" $ do
+            readExample "CoffeeSouffle"
+
+        it "OlivierSalad parses without error" $ do
+            readExample "OlivierSalad"
+
+-- | Extract step items from the first step of an unnamed section.
+stepItems :: Recipe -> [StepItem]
+stepItems r =
+    let s = NE.head (recipeSections r)
+     in case NE.head (sectionBody s) of
+            SecStep step -> unStep step
+            _ -> []