Add test for custom selector; fix & enable custom SUM() test

Author: eemeli

fluent-bundle/test/functions_runtime_test.js

@@ -5,6 +5,7 @@ import ftl from "@fluent/dedent";
 
 import { FluentBundle } from "../esm/bundle.js";
 import { FluentResource } from "../esm/resource.js";
+import { FluentNumber } from "../esm/types.js";
 
 suite("Runtime-specific functions", function () {
   let bundle, args, errs;
@@ -19,13 +20,20 @@ suite("Runtime-specific functions", function () {
         useIsolating: false,
         functions: {
           CONCAT: (args, kwargs) => args.reduce((a, b) => `${a}${b}`, ""),
-          SUM: (args, kwargs) => args.reduce((a, b) => a + b, 0),
+          SUM: (args, kwargs) =>
+            new FluentNumber(args.reduce((a, b) => a + b, 0)),
+          PLATFORM: () => "windows",
         },
       });
       bundle.addResource(
         new FluentResource(ftl`
         foo = { CONCAT("Foo", "Bar") }
         bar = { SUM(1, 2) }
+        pref =
+          { PLATFORM() ->
+              [windows] Options
+             *[other] Preferences
+          }
         `)
       );
     });
@@ -37,9 +45,14 @@ suite("Runtime-specific functions", function () {
       assert.strictEqual(errs.length, 0);
     });
 
-    // XXX When they are passed as variables, convert JS types to FTL types
-    // https://bugzil.la/1307116
-    test.skip("works for numbers", function () {
+    test("works for selectors", function () {
+      const msg = bundle.getMessage("pref");
+      const val = bundle.formatPattern(msg.value, args, errs);
+      assert.strictEqual(val, "Options");
+      assert.strictEqual(errs.length, 0);
+    });
+
+    test("works for numbers", function () {
       const msg = bundle.getMessage("bar");
       const val = bundle.formatPattern(msg.value, args, errs);
       assert.strictEqual(val, "3");