opal · Dec 25, 2013 · Dec 25, 2013 · Dec 25, 2013 · Dec 25, 2013 · Dec 25, 2013
Showing with 113 additions and 29 deletions.

+16 −0 spec/opal/stdlib/promise/then_spec.rb

+15 −0 spec/opal/stdlib/promise/when_spec.rb

+82 −29 stdlib/promise.rb
diff --git a/spec/opal/stdlib/promise/then_spec.rb b/spec/opal/stdlib/promise/then_spec.rb
@@ -35,4 +35,20 @@
 
     x.should == 23
   end
+
+  it 'sends raised exceptions as rejections' do
+    x = nil
+
+    Promise.value(2).then { raise "hue" }.rescue { |v| x = v }
+
+    x.should be_kind_of(RuntimeError)
+  end
+
+  it 'sends raised exceptions inside rescue blocks as next errors' do
+    x = nil
+
+    Promise.value(2).then { raise "hue" }.rescue { raise "omg" }.rescue { |v| x = v }
+
+    x.should be_kind_of(RuntimeError)
+  end
 end
diff --git a/spec/opal/stdlib/promise/when_spec.rb b/spec/opal/stdlib/promise/when_spec.rb
@@ -16,4 +16,19 @@
 
     x.should == 3
   end
+
+  it 'can be built lazily' do
+    a = Promise.new
+    b = Promise.value(3)
+
+    x = 42
+
+    Promise.when(a).and(b).then {|c, d|
+      x = c + d
+    }
+
+    a.resolve(2)
+
+    x.should == 5
+  end
 end
diff --git a/stdlib/promise.rb b/stdlib/promise.rb
@@ -17,10 +17,11 @@ def initialize(success = nil, failure = nil)
     @success = success
     @failure = failure
 
-    @realized = nil
-    @value    = nil
-    @error    = nil
-    @delayed  = nil
+    @realized  = nil
+    @exception = false
+    @value     = nil
+    @error     = nil
+    @delayed   = nil
 
     @prev = nil
     @next = nil
@@ -30,16 +31,20 @@ def act?
     @success != nil
   end
 
+  def exception?
+    @exception
+  end
+
   def realized?
     @realized != nil
   end
 
   def resolved?
-    @realized == :value
+    @realized == :resolve
   end
 
   def rejected?
-    @realized == :error
+    @realized == :reject
   end
 
   def ^(promise)
@@ -58,7 +63,9 @@ def <<(promise)
   def >>(promise)
     @next = promise
 
-    if resolved?
+    if exception?
+      promise.reject(@delayed)
+    elsif resolved?
       promise.resolve(@delayed || value)
     elsif rejected? && (!@failure || Promise === (@delayed || @error))
       promise.reject(@delayed || error)
@@ -78,20 +85,28 @@ def resolve(value)
       return value ^ self
     end
 
-    @realized = :value
+    @realized = :resolve
     @value    = value
 
-    if @success
-      value = @success.call(value)
+    begin
+      if @success
+        value = @success.call(value)
+      end
+
+      resolve!(value)
+    rescue Exception => e
+      exception!(e)
     end
 
+    self
+  end
+
+  def resolve!(value)
     if @next
       @next.resolve(value)
     else
       @delayed = value
     end
-
-    self
   end
 
   def reject(value)
@@ -105,30 +120,40 @@ def reject(value)
       return value ^ self
     end
 
-    @realized = :error
+    @realized = :reject
     @error    = value
 
-    if @failure
-      value = @failure.call(value)
+    begin
+      if @failure
+        value = @failure.call(value)
 
-      if Promise === value
-        if @next
-          @next.reject(value)
-        else
-          @delayed = value
+        if Promise === value
+          reject!(value)
         end
-      end
-    else
-      if @next
-        @next.reject(value)
       else
-        @delayed = value
+        reject!(value)
       end
+    rescue Exception => e
+      exception!(e)
     end
 
     self
   end
 
+  def reject!(value)
+    if @next
+      @next.reject(value)
+    else
+      @delayed = value
+    end
+  end
+
+  def exception!(error)
+    @exception = true
+
+    reject!(error)
+  end
+
   def then(&block)
     self ^ Promise.new(block)
   end
@@ -202,7 +227,37 @@ def initialize(promises = [])
       }
     end
 
+    def each(&block)
+      raise ArgumentError, 'no block given' unless block
+
+      self.then {|values|
+        values.each(&block)
+      }
+    end
+
+    def collect(&block)
+      raise ArgumentError, 'no block given' unless block
+
+      self.then {|values|
+        Promise.when values.map(&block)
+      }
+    end
+
+    def inject(*args, &block)
+      self.then {|values|
+        values.reduce(*args, &block)
+      }
+    end
+
+    alias map collect
+
+    alias reduce inject
+
     def wait(promise)
+      unless Promise === promise
+        promise = Promise.value(promise)
+      end
+
       @wait << promise
 
       promise.always {
@@ -212,6 +267,8 @@ def wait(promise)
       self
     end
 
+    alias and wait
+
     def >>(*)
       super.tap {
         try
@@ -227,9 +284,5 @@ def try
         end
       end
     end
-
-    def and(&block)
-      wait Promise.new(block)
-    end
   end
 end