From 241632aaa118610077646ad59b3f9eda25d298ea Mon Sep 17 00:00:00 2001
From: Yegor Jbanov <yjbanov@google.com>
Date: Tue, 15 Sep 2015 12:11:26 -0700
Subject: [PATCH] feat(code size): make assertionsEnabled() statically
 computable by dart2js

Our existing implementation prevented dart2js from statically deducing the
return value. This fix does not yet result in better tree-shaking due to the
following dart2js bugs:

https://github.com/dart-lang/sdk/issues/24354
https://github.com/dart-lang/sdk/issues/24355

Closes #4198
---
 modules/angular2/src/core/facade/lang.dart | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/modules/angular2/src/core/facade/lang.dart b/modules/angular2/src/core/facade/lang.dart
index 3939834ec5..9ff4b23fd9 100644
--- a/modules/angular2/src/core/facade/lang.dart
+++ b/modules/angular2/src/core/facade/lang.dart
@@ -243,17 +243,11 @@ bool isJsObject(o) {
   return false;
 }
 
-var _assertionsEnabled = null;
 bool assertionsEnabled() {
-  if (_assertionsEnabled == null) {
-    try {
-      assert(false);
-      _assertionsEnabled = false;
-    } catch (e) {
-      _assertionsEnabled = true;
-    }
-  }
-  return _assertionsEnabled;
+  // TODO(yjbanov): verify that this is inlined after https://github.com/dart-lang/sdk/issues/24355
+  bool k = false;
+  assert((k = true));
+  return k;
 }
 
 // Can't be all uppercase as our transpiler would think it is a special directive...