plugins/oil-git-status: improve signcolumn warning

The warning should trigger when a valid value is configured that
restricts the sign column to less than 2 columns.

plugins/by-name/oil-git-status/default.nix

@@ -58,29 +58,46 @@ lib.nixvim.plugins.mkNeovimPlugin {
           ${options.plugins.oil.enable} = true;
         '';
       }
-      {
+      (
-        when =
+        # The plugin requires the oil configuration allow at least 2 sign columns.
+        # They suggest `win_options.signcolumn = "yes:2"`, but valid options include
+        # any "yes" or "auto" with a max > 1: E.g. "auto:2", "auto:1-2", "yes:3", …
+        # See also `:h 'signcolumn'`
         let
+          # Get `signcolumn` setting value
           value = config.plugins.oil.settings.win_options.signcolumn or null;
-            isKnownBadStr = lib.lists.elem value [
+
+          # These valid values do not allow the sign column to use more than one column,
+          # So they are incompatible with oil-git-status.
+          badValue = builtins.elem value [
+            "no"
+            "number"
+            "auto"
+            "auto:1"
             "yes"
-              "yes:"
-              "yes:0"
             "yes:1"
           ];
-            hasYes = lib.strings.hasInfix "yes" value;
-          in
-          !(lib.strings.isString value && hasYes && !isKnownBadStr);
 
+          currentValueNote =
+            lib.optionalString (value != null)
+              "\n`${options.plugins.oil.settings}.win_options.signcolumn` is currently set to ${
+                lib.generators.toPretty { } value
+              }.";
+        in
+        {
+          when = builtins.isString value -> badValue;
           message = ''
-          This plugin requires the following `plugins.oil` setting:
+            This plugin requires `plugins.oil` is configured to allow at least 2 sign columns.${currentValueNote}
+            E.g:
               ${options.plugins.oil.settings} = {
                 win_options = {
                   signcolumn = "yes:2";
                 };
               };`
+            See :h 'signcolumn' for more options
           '';
         }
+      )
     ];
   };
 

tests/test-sources/plugins/by-name/oil-git-status/default.nix

@@ -31,4 +31,19 @@
     plugins.oil-git-status.enable = true;
   };
 
+  bad-signcolumn_yes = {
+    test.buildNixvim = false;
+    test.warnings = expect: [
+      (expect "count" 1)
+      (expect "any" "Nixvim (plugins.oil-git-status): This plugin requires `plugins.oil` is configured to allow at least 2 sign columns.")
+      (expect "any" "`plugins.oil.settings.win_options.signcolumn` is currently set to \"yes\".")
+    ];
+
+    plugins.oil = {
+      enable = true;
+      # Should trigger the warning
+      settings.win_options.signcolumn = "yes";
+    };
+    plugins.oil-git-status.enable = true;
+  };
 }