add wezterm.has_action

refs: https://github.com/wez/wezterm/issues/3454

config/src/lua.rs

@@ -346,6 +346,12 @@ end
         )?;
         wezterm_mod.set("hostname", lua.create_function(hostname)?)?;
         wezterm_mod.set("action", luahelper::enumctor::Enum::<KeyAssignment>::new())?;
+        wezterm_mod.set(
+            "has_action",
+            lua.create_function(|_lua, name: String| {
+                Ok(KeyAssignment::variants().contains(&name.as_str()))
+            })?,
+        )?;
 
         lua.set_named_registry_value(LUA_REGISTRY_USER_CALLBACK_COUNT, 0)?;
         wezterm_mod.set("action_callback", lua.create_function(action_callback)?)?;

docs/changelog.md

@@ -67,6 +67,8 @@ As features stabilize some brief notes about them will accumulate here.
 * [pane:get_tty_name()](config/lua/pane/get_tty_name.md) and
   [PaneInformation.tty_name](config/lua/PaneInformation.md) to reason about the
   tty name on local unix systems.
+* [wezterm.has_action()](config/lua/wezterm/has_action.md) makes it easier to
+  author a wezterm config that works across different wezterm versions. #3454
 
 #### Fixed
 * mux: Stale remote window mapping could prevent spawning new tabs in remote domain. #2759

docs/config/lua/wezterm/has_action.md

@@ -0,0 +1,21 @@
+# wezterm.has_action(NAME)
+
+{{since('nightly')}}
+
+Returns true if the string *NAME* is a valid key assignment action variant
+that can be used with [wezterm.action](action.md).
+
+This is useful when you want to use a wezterm configuration across multiple
+different versions of wezterm.
+
+```lua
+if wezterm.has_action 'PromptInputLine' then
+  table.insert(config.keys, {
+    key = 'p',
+    mods = 'LEADER',
+    action = wezterm.action.PromptInputLine {
+      -- other parameters here
+    },
+  })
+end
+```