From 02dd1cf2360cb2a650cb61c5e6ae2ca573eb5125 Mon Sep 17 00:00:00 2001
From: samgd <sam@samgd.com>
Date: Fri, 22 Jul 2016 16:39:22 +0200
Subject: [PATCH] Add Trim_ data constructors. Add If test for Trim

---
 src/Hakyll/Web/Template/Internal.hs | 16 ++++++++++------
 tests/Hakyll/Web/Template/Tests.hs  | 15 +++++++++++++++
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/src/Hakyll/Web/Template/Internal.hs b/src/Hakyll/Web/Template/Internal.hs
index 45db2e4..2f702f9 100644
--- a/src/Hakyll/Web/Template/Internal.hs
+++ b/src/Hakyll/Web/Template/Internal.hs
@@ -64,6 +64,8 @@ data TemplateElement
     | If TemplateExpr Template (Maybe Template)   -- expr, then, else
     | For TemplateExpr Template (Maybe Template)  -- expr, body, separator
     | Partial TemplateExpr                        -- filename
+    | TrimL
+    | TrimR
     deriving (Show, Eq, Typeable)
 
 
@@ -71,10 +73,12 @@ data TemplateElement
 instance Binary TemplateElement where
     put (Chunk string) = putWord8 0 >> put string
     put (Expr e)       = putWord8 1 >> put e
-    put (Escaped)      = putWord8 2
-    put (If e t f  )   = putWord8 3 >> put e >> put t >> put f
+    put  Escaped       = putWord8 2
+    put (If e t f)     = putWord8 3 >> put e >> put t >> put f
     put (For e b s)    = putWord8 4 >> put e >> put b >> put s
     put (Partial e)    = putWord8 5 >> put e
+    put  TrimL         = putWord8 6
+    put  TrimR         = putWord8 7
 
     get = getWord8 >>= \tag -> case tag of
         0 -> Chunk <$> get
@@ -83,8 +87,9 @@ instance Binary TemplateElement where
         3 -> If <$> get <*> get <*> get
         4 -> For <$> get <*> get <*> get
         5 -> Partial <$> get
-        _ -> error $
-            "Hakyll.Web.Template.Internal: Error reading cached template"
+        6 -> pure TrimL
+        7 -> pure TrimR
+        _ -> error "Hakyll.Web.Template.Internal: Error reading cached template"
 
 
 --------------------------------------------------------------------------------
@@ -114,8 +119,7 @@ instance Binary TemplateExpr where
         0 -> Ident         <$> get
         1 -> Call          <$> get <*> get
         2 -> StringLiteral <$> get
-        _ -> error $
-            "Hakyll.Web.Tamplte.Internal: Error reading cached template"
+        _ -> error "Hakyll.Web.Template.Internal: Error reading cached template"
 
 
 --------------------------------------------------------------------------------
diff --git a/tests/Hakyll/Web/Template/Tests.hs b/tests/Hakyll/Web/Template/Tests.hs
index 7d5d6ec..453cd49 100644
--- a/tests/Hakyll/Web/Template/Tests.hs
+++ b/tests/Hakyll/Web/Template/Tests.hs
@@ -39,6 +39,21 @@ tests = testGroup "Hakyll.Core.Template.Tests" $ concat
                 (Template [Chunk "foo"])
                 Nothing]
             @=?  readTemplate "$if(a(\"bar\"))$foo$endif$"
+        -- 'If' 'Trim_' test.
+        , Template
+            [ TrimL
+            , If (Ident (TemplateKey "body"))
+                 (Template [ TrimR
+                           , Expr (Ident (TemplateKey "body"))
+                           ])
+                 (Just (Template [ TrimL
+                                 , TrimR
+                                 , Expr (Ident (TemplateKey "body"))
+                                 ]))
+            , TrimL
+            , TrimR
+            ]
+            @=? readTemplate "$-if(body)-$\n$body$\n$-else-$\n$body$\n$-endif-$"
         ]
     ]