[gi-docgen/ebassi/deprecated-since: 2/3] gir: Simplify deprecation check

[Emmanuele Bassi <ebassi src gnome org>]

commit 8a3af64fe57d660ec7b326e1e14cc8217c83f592
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Mon Jan 31 00:04:44 2022 +0000

    gir: Simplify deprecation check
    
    Add a proxy for the deprecation bit, and return placeholder values in
    case version or message are missing.

 gidocgen/gir/ast.py | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
---
diff --git a/gidocgen/gir/ast.py b/gidocgen/gir/ast.py
index 621c241..fbac892 100644
--- a/gidocgen/gir/ast.py
+++ b/gidocgen/gir/ast.py
@@ -151,12 +151,18 @@ class GIRElement:
     def available_since(self) -> T.Optional[str]:
         return self.info.version
 
+    @property
+    def deprecated(self) -> bool:
+        return self.info.deprecated
+
     @property
     def deprecated_since(self) -> T.Optional[T.Tuple[str, str]]:
-        version = self.info.deprecated_version
-        if version is None:
+        if not self.info.deprecated:
             return None
+        version = self.info.deprecated_version
         message = self.info.deprecated_msg
+        if version is None:
+            version = "Unknown"
         if message is None:
             message = "Please do not use it in newly written code"
         return (version, message)