fix(observable): readonly and non-configurable property should return…

… the actual value

.changeset/spotty-boxes-applaud.md

@@ -0,0 +1,12 @@
+---
+'@difizen/mana-observable': patch
+'@difizen/mana-syringe': patch
+'@difizen/mana-common': patch
+'@difizen/mana-react': patch
+'@difizen/mana-core': patch
+'@difizen/mana-l10n': patch
+'@difizen/mana-app': patch
+'@difizen/mana-docs': patch
+---
+
+Readonly & non-configurable property should return the actual value

packages/mana-observable/src/tracker.spec.ts

@@ -596,4 +596,36 @@ describe('Tracker', () => {
 
     assert(!!tryInvokeGetter(proxyBaz.bar, proxyBaz, baz));
   });
+
+  it('#get readonly & non-configurable property', () => {
+    class Foo {}
+
+    class Bar {
+      name = 'Bar';
+    }
+    const foo = new Foo();
+    const bar = new Bar();
+
+    Object.defineProperty(foo, 'prop', {
+      value: bar,
+      writable: false,
+      configurable: false,
+    });
+
+    try {
+      let changeCount = 0;
+      const reaction = () => {
+        const trackable = Tracker.track(foo, reaction);
+        if ('prop' in trackable) {
+          const b = trackable['prop'] as Bar;
+          b.name;
+        }
+        changeCount += 1;
+      };
+      reaction(); // 1
+      assert(changeCount === 1);
+    } catch (e) {
+      assert(!e);
+    }
+  });
 });

packages/mana-observable/src/tracker.ts

@@ -153,6 +153,10 @@ export namespace Tracker {
             return track(value, act, true);
           }
           const descriptor = getPropertyDescriptor(target, property);
+          if (descriptor?.configurable === false && descriptor?.writable === false) {
+            // non-configurable and non-writable property should return the actual value
+            return target[property];
+          }
           if (descriptor?.get) {
             return tryInvokeGetter(descriptor.get, proxy, target);
           }