test(pandoc): add more tests for pandoc helper functions

test/PandocSpec.hs

@@ -11,17 +11,28 @@ import Text.Pandoc.Arbitrary
 
 
 spec :: Spec
-spec = describe "addMeta" $ do
-  it "should overwrite existing settings" $ do
-    metaOverwrite <- arbitrary
-    pd <- arbitrary
-    let (Pandoc newMeta _) = addMeta metaOverwrite pd
-    Map.toList newMeta `shouldContain` Map.toList metaOverwrite
+spec = do
+  describe "addMeta" $ do
+    it "should overwrite existing settings" $ do
+      metaOverwrite <- arbitrary
+      pd <- arbitrary
+      let (Pandoc newMeta _) = addMeta metaOverwrite pd
+      Map.toList newMeta `shouldContain` Map.toList metaOverwrite
 
-  it "should preserve untouched settings" $ do
-    metaOverwrite <- arbitrary
-    pd <- arbitrary
-    let
-      (Pandoc keptMeta _) = pd
-      (Pandoc newMeta  _) = addMeta metaOverwrite pd
-    Map.toList newMeta `shouldContain` Map.toList (keptMeta `Map.difference` metaOverwrite)
+    it "should preserve untouched settings" $ do
+      metaOverwrite <- arbitrary
+      pd <- arbitrary
+      let
+        (Pandoc keptMeta _) = pd
+        (Pandoc newMeta  _) = addMeta metaOverwrite pd
+      Map.toList newMeta `shouldContain` Map.toList (keptMeta `Map.difference` metaOverwrite)
+  
+    it "should preserve document block" $ do
+      metaOverwrite <- arbitrary
+      pd <- arbitrary
+      let
+        (Pandoc _ oldBlocks) = pd
+        (Pandoc - newBlocks) = addMeta metaOverwrite pd
+      oldBlocks `shouldBe` newBlocks
+      
+  describe "_Meta" . it "is a lens" . property $ isLens _Meta