From a9702991100ef8fc485ec47aed3d854c45e19dac Mon Sep 17 00:00:00 2001
From: Jaro <jaro@argonaut-constellation.org>
Date: Tue, 6 Jun 2023 10:25:19 +0200
Subject: [PATCH] Test unions of lists of rectangles.

---
 test/Data/Text/ParagraphLayout/RectSpec.hs | 78 +++++++++++++++++++---
 1 file changed, 70 insertions(+), 8 deletions(-)

diff --git a/test/Data/Text/ParagraphLayout/RectSpec.hs b/test/Data/Text/ParagraphLayout/RectSpec.hs
index 012b854..e5236e2 100644
--- a/test/Data/Text/ParagraphLayout/RectSpec.hs
+++ b/test/Data/Text/ParagraphLayout/RectSpec.hs
@@ -1,6 +1,7 @@
 module Data.Text.ParagraphLayout.RectSpec (spec) where
 
 import Data.Int (Int32)
+import Data.List.NonEmpty (NonEmpty ((:|)))
 
 import Test.Hspec
 import Data.Text.ParagraphLayout.Internal.Rect
@@ -13,14 +14,75 @@ negativeRect = Rect 80 (-75) (-15) (-15)
 
 spec :: Spec
 spec = do
-    describe "union of two rects (low X, low Y)" $
-        llSpec $ union LL positiveRect negativeRect
-    describe "union of two rects (low X, high Y)" $
-        lhSpec $ union LH positiveRect negativeRect
-    describe "union of two rects (high X, low Y)" $
-        hlSpec $ union HL positiveRect negativeRect
-    describe "union of two rects (high X, high Y)" $
-        hhSpec $ union HH positiveRect negativeRect
+
+    describe "union of two rects" $ do
+
+        describe "low X, low Y" $
+            llSpec $ union LL positiveRect negativeRect
+
+        describe "low X, high Y" $
+            lhSpec $ union LH positiveRect negativeRect
+
+        describe "high X, low Y" $
+            hlSpec $ union HL positiveRect negativeRect
+
+        describe "high X, high Y" $
+            hhSpec $ union HH positiveRect negativeRect
+
+    describe "union of list" $ do
+
+        describe "when empty" $
+            it "should be Nothing" $ do
+                unionMany LL []
+                    `shouldBe` (Nothing :: Maybe (Rect Int32))
+
+        describe "with single item" $ do
+
+            describe "matching LL origin" $
+                it "should be identity" $
+                    unionMany LL [positiveRect]
+                        `shouldBe` Just positiveRect
+
+            describe "matching HH origin" $
+                it "should be identity" $
+                    unionMany HH [negativeRect]
+                        `shouldBe` Just negativeRect
+
+        describe "with single item repeated" $ do
+
+            describe "matching LL origin" $
+                it "should be equal to item" $
+                    unionMany LL (replicate 2 positiveRect)
+                        `shouldBe` Just positiveRect
+
+            describe "matching HH origin" $
+                it "should be equal to item" $
+                    unionMany HH (replicate 7 negativeRect)
+                        `shouldBe` Just negativeRect
+
+        describe "with two items" $
+            it "should behave the same as binary function" $
+                unionMany LL [positiveRect, negativeRect]
+                    `shouldBe` Just (union LL positiveRect negativeRect)
+
+    describe "union of non-empty list" $ do
+
+        describe "with single item" $ do
+
+            describe "matching LL origin" $
+                it "should be identity" $
+                    unionMany1 LL (positiveRect :| [])
+                        `shouldBe` positiveRect
+
+            describe "matching HH origin" $
+                it "should be identity" $
+                    unionMany1 HH (negativeRect :| [])
+                        `shouldBe` negativeRect
+
+        describe "with two items" $
+            it "should behave the same as binary function" $
+                unionMany1 LL (positiveRect :| [negativeRect])
+                    `shouldBe` union LL positiveRect negativeRect
 
 llSpec :: Rect Int32 -> SpecWith ()
 llSpec r = do
-- 
2.30.2