Add a maximum depth parameter to Promise#trace

meh · meh · commit ed483ce30f3e · 2014-09-16T20:07:21.000+02:00
diff --git a/stdlib/promise.rb b/stdlib/promise.rb
@@ -174,8 +174,8 @@ def always(&block)
   alias finally always
   alias ensure always
 
-  def trace(&block)
-    self ^ Trace.new(block)
+  def trace(depth = nil, &block)
+    self ^ Trace.new(depth, block)
   end
 
   def inspect
@@ -209,9 +209,17 @@ def self.it(promise)
       end
     end
 
-    def initialize(block)
+    def initialize(depth, block)
+      @depth = depth
+
       super -> {
-        block.call(*Trace.it(self).reverse)
+        trace = Trace.it(self).reverse
+
+        if depth && depth <= trace.length
+          trace.shift(trace.length - depth)
+        end
+
+        block.call(*trace)
       }
     end
   end
