From f6114fa5642389678f0935186cc66c2dde41849f Mon Sep 17 00:00:00 2001
From: niels <33730531+yndolg@users.noreply.github.com>
Date: Sat, 12 Oct 2024 17:35:30 +0200
Subject: [PATCH] Cabal ignore if for completions

If conditions were previously handled as normal sections, for which we
don't have any completion information. Now, we ignore the if section
and use the parent section for completion purposes.

Co-authored-by: Niels Glodny <33730531-yndolg@users.noreply.github.com>
---
 .../Plugin/Cabal/Completion/Completions.hs    |  2 ++
 plugins/hls-cabal-plugin/test/Context.hs      | 21 +++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/plugins/hls-cabal-plugin/src/Ide/Plugin/Cabal/Completion/Completions.hs b/plugins/hls-cabal-plugin/src/Ide/Plugin/Cabal/Completion/Completions.hs
index 04b6562270..83e809fb0f 100644
--- a/plugins/hls-cabal-plugin/src/Ide/Plugin/Cabal/Completion/Completions.hs
+++ b/plugins/hls-cabal-plugin/src/Ide/Plugin/Cabal/Completion/Completions.hs
@@ -140,6 +140,7 @@ findCursorContext cursor parentHistory prefixText fields =
     Just field@(Syntax.Field _ _) -> classifyFieldContext parentHistory cursor field
     Just section@(Syntax.Section _ args sectionFields)
       | inSameLineAsSectionName section -> (stanzaCtx, None) -- TODO: test whether keyword in same line is parsed correctly
+      | getFieldName section `elem` conditionalKeywords -> findCursorContext cursor parentHistory prefixText sectionFields -- Ignore if conditionals, they are not real sections
       | otherwise ->
           findCursorContext cursor
             (NE.cons (Syntax.positionCol (getAnnotation section) + 1, Stanza (getFieldName section) (getOptionalSectionName args)) parentHistory)
@@ -147,6 +148,7 @@ findCursorContext cursor parentHistory prefixText fields =
     where
         inSameLineAsSectionName section = Syntax.positionRow (getAnnotation section) == Syntax.positionRow cursor
         stanzaCtx = snd $ NE.head parentHistory
+        conditionalKeywords = ["if", "elif", "else"]
 
 -- | Finds the cursor's context, where the cursor is already found to be in a specific field
 --
diff --git a/plugins/hls-cabal-plugin/test/Context.hs b/plugins/hls-cabal-plugin/test/Context.hs
index 82d50ccf14..8e6176bc5b 100644
--- a/plugins/hls-cabal-plugin/test/Context.hs
+++ b/plugins/hls-cabal-plugin/test/Context.hs
@@ -154,6 +154,15 @@ getContextTests =
         , testCase "Top level - cursor in later line with partially written value" $ do
             ctx <- callGetContext (Position 5 13) "eee" topLevelData
             ctx @?= (TopLevel, KeyWord "name:")
+        , testCase "If is ignored" $ do
+            ctx <- callGetContext (Position 5 18) "" conditionalData
+            ctx @?= (Stanza "library" Nothing, None)
+        , testCase "Elif is ignored" $ do
+            ctx <- callGetContext (Position 7 18) "" conditionalData
+            ctx @?= (Stanza "library" Nothing, None)
+        , testCase "Else is ignored" $ do
+            ctx <- callGetContext (Position 9 18) "" conditionalData
+            ctx @?= (Stanza "library" Nothing, KeyWord "buildable:")
         , testCase "Named Stanza" $ do
             ctx <- callGetContext (Position 2 18) "" executableStanzaData
             ctx @?= (TopLevel, None)
@@ -237,6 +246,18 @@ name:
           eee
 |]
 
+conditionalData :: T.Text
+conditionalData = [trimming|
+cabal-version:      3.0
+name:               simple-cabal
+library
+    if os(windows)
+       buildable:
+    elif os(linux)
+       buildable:
+    else
+       buildable:
+|]
 multiLineOptsData :: T.Text
 multiLineOptsData = [trimming|
 cabal-version:      3.0