Add ElixirScript.JS.mutate

bryanjos · bryanjos · commit 2425a563cb57 · 2017-07-15T23:44:57.000-05:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -8,6 +8,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 - ElixirScript now has an FFI layer for interoperability with JavaScript. For more details, see documentation at `ElixirScript.FFI`
+- ElixirScript.JS.mutate/2
+- ElixirScript.JS.mutate/3
 
 ### Changed
 - Compiler has been completely rewritten. ElixirScript now requires Erlang 20+ and Elixir 1.5+
diff --git a/lib/elixir_script/lib/js.ex b/lib/elixir_script/lib/js.ex
@@ -37,4 +37,18 @@ defmodule ElixirScript.JS do
   The current JavaScript context
   """
   defmacro this()
+
+  @doc """
+  Mutates an existing JavaScript object.
+  ex:
+    ElixirScript.JS.mutate elem, %{"width" => 100}
+  """
+  defmacro update(object, map)
+
+  @doc """
+  Mutates an existing JavaScript object.
+  ex:
+    ElixirScript.JS.mutate elem, "width", 100
+  """
+  defmacro update(object, key, value)
 end
diff --git a/lib/elixir_script/passes/translate/forms/js.ex b/lib/elixir_script/passes/translate/forms/js.ex
@@ -16,16 +16,6 @@ defmodule ElixirScript.Translate.Forms.JS do
     )
   end
 
-  def global() do
-    J.member_expression(
-      J.member_expression(
-        J.identifier("Bootstrap"),
-        J.identifier("Core")
-      ),
-      J.identifier("global")
-    )
-  end
-
   def compile({{:., _, [ElixirScript.JS, :debugger]}, _, _}, state) do
     ast = J.debugger_statement()
     {ast, state}
@@ -77,4 +67,35 @@ defmodule ElixirScript.Translate.Forms.JS do
 
     {ast, state}
   end
+
+  def compile({{:., _, [ElixirScript.JS, :mutate]}, _, [object, map]}, state) do
+    ast = J.call_expression(
+      J.member_expression(
+        J.identifier("Object"),
+        J.identifier("assign")
+      ),
+      [
+        Form.compile!(object, state),
+        Form.compile!(map, state)
+      ]
+    )
+
+    {ast, state}
+  end
+
+  def compile({{:., _, [ElixirScript.JS, :mutate]}, _, [object, key, value]}, state) do
+    ast = J.assignment_expression(
+      :=,
+      J.member_expression(
+        Form.compile!(object, state),
+        Form.compile!(key, state),
+        true
+      ),
+      [
+        Form.compile!(value, state)
+      ]
+    )
+
+    {ast, state}
+  end
 end
diff --git a/test/passes/translate/forms/js_test.exs b/test/passes/translate/forms/js_test.exs
@@ -64,4 +64,55 @@ defmodule ElixirScript.Translate.Forms.JS.Test do
       [J.literal("react")]
     )
   end
+
+  test "mutate/2" do
+    properties = [{"a", 1}]
+    map_ast = {:%{}, [], properties}
+
+    ast = {{:., [], [ElixirScript.JS, :mutate]}, [], [{:%{}, [], []}, map_ast]}
+    state = %{function: {:each, nil}, module: Enum, vars: %{:_ => 0, "entry" => 0, "enumerable" => 0, "fun" => 0}}
+
+    {js_ast, _} = Form.compile(ast, state)
+    assert js_ast == J.call_expression(
+      J.member_expression(
+        J.identifier("Object"),
+        J.identifier("assign")
+      ),
+      [
+        J.object_expression([]),
+        J.object_expression([
+          J.property(
+            J.identifier("a"),
+            J.literal(1)
+          )
+        ])
+      ]
+    )
+  end
+
+  test "mutate/3" do
+    properties = [{"a", 1}]
+    map_ast = {:%{}, [], properties}
+
+    ast = {{:., [], [ElixirScript.JS, :mutate]}, [], [map_ast, "a", 2]}
+    state = %{function: {:each, nil}, module: Enum, vars: %{:_ => 0, "entry" => 0, "enumerable" => 0, "fun" => 0}}
+
+    {js_ast, _} = Form.compile(ast, state)
+    assert js_ast == J.assignment_expression(
+      :=,
+      J.member_expression(
+        J.object_expression([
+          J.property(
+            J.identifier("a"),
+            J.literal(1)
+          )
+        ]),
+        J.literal("a"),
+        true
+      ),
+      [
+        J.literal(2)
+      ]
+    )
+  end
 end
