Test v1 completion protocol

(cherry picked from commit 9934680)

src/Options/Applicative.hs

@@ -215,6 +215,7 @@ module Options.Applicative (
   Completer,
   mkCompleter,
   CompletionItem(..),
+  CompletionItemOptions(..),
   mkCompleterWithOptions,
   listIOCompleter,
 

src/Options/Applicative/BashCompletion.hs

@@ -31,6 +31,12 @@ data Features = Features
   , protocolVersion :: Int
   }
 
+-- | Version of the output format that the shell integration script
+-- expects optparse-applicative to write to stdout.
+--
+-- Version increases should be rare, because most changes
+-- can be handled by adding a new % keyword. Unknown keywords
+-- are ignored by the shell integration scripts.
 currentProtocolVerson :: Int
 currentProtocolVerson = 1
 

tests/test.hs

@@ -468,6 +468,36 @@ prop_completion_rich_lengths = once . ioProperty $
     Failure _   -> return $ counterexample "unexpected failure" failed
     Success val -> return $ counterexample ("unexpected result " ++ show val) failed
 
+prop_completion_v1_default :: Property
+prop_completion_v1_default = once . ioProperty $
+  let p :: Parser String
+      p = strArgument (completer (mkCompleterWithOptions (pure (pure [CompletionItem mempty "reachable"]))))
+      i = info p idm
+      result = run i [ "--optparse-completion-version", "1"
+                     , "--bash-completion-index=0"
+                     ]
+  in case result of
+    CompletionInvoked (CompletionResult err) -> do
+      completions <- lines <$> err "test"
+      return $ ["%addspace", "%files", "%value", "reachable"] === completions
+    Failure _   -> return $ counterexample "unexpected failure" failed
+    Success val -> return $ counterexample ("unexpected result " ++ show val) failed
+
+prop_completion_v1_minimal :: Property
+prop_completion_v1_minimal = once . ioProperty $
+  let p :: Parser String
+      p = strArgument (completer (mkCompleterWithOptions (pure (pure [CompletionItem (mempty { cioAddSpace = False, cioFiles = False }) "reachable"]))))
+      i = info p idm
+      result = run i [ "--optparse-completion-version", "1"
+                     , "--bash-completion-index=0"
+                     ]
+  in case result of
+    CompletionInvoked (CompletionResult err) -> do
+      completions <- lines <$> err "test"
+      return $ ["%value", "reachable"] === completions
+    Failure _   -> return $ counterexample "unexpected failure" failed
+    Success val -> return $ counterexample ("unexpected result " ++ show val) failed
+
 prop_bind_usage :: Property
 prop_bind_usage = once $
   let p :: Parser [String]