Teach dart_package to understand the packages/ subdirectory

mojo/public/dart/rules.gni

Index: mojo/public/dart/rules.gni
diff --git a/mojo/public/dart/rules.gni b/mojo/public/dart/rules.gni
index 036c0733ec77ec9cb49b1b6116220cb093c5f011..94b50efa93d71202ef9430dd413bac468c7a0971 100644
--- a/mojo/public/dart/rules.gni
+++ b/mojo/public/dart/rules.gni
@@ -4,23 +4,64 @@
 
 # Rules to generate python packaged applications for Dart
 
-import("../mojo_sdk.gni")
+import("//build/module_args/mojo.gni")
 
 template("dart_package") {
   package_target_name = "$target_name"
   package_output = "$target_out_dir/$target_name.dartzip"
 
+  if (defined(invoker.uses_pub) && invoker.uses_pub) {
+    # Pull in any dependencies specified via pubspec.yaml and repackage them in
+    # a dartzip file.
+    action("${package_target_name}_pub_get") {
+      target_dir = get_label_info(":$target_name", "dir")
+      script = rebase_path("mojo/public/tools/gn/zip.py", ".", mojo_sdk_root)
+
+      # Run pub get and get a list of the pulled-in files as inputs.
+      pub_get_script =
+          rebase_path("mojo/public/tools/dart_pub_get.py", ".", mojo_sdk_root)
+      rebase_dart_sdk_root = rebase_path(mojo_dart_sdk_root, root_build_dir)
+      rebase_target_dir = rebase_path(target_dir, root_build_dir)
+      inputs = exec_script(pub_get_script,

[tonyg, 2015/04/08 13:52:38]

Curious about a couple of things:
1. Does pub get try to run every time, or does this rule know not to try if
there's a stamp file or something?
2. What does it look like to the user when they're offline and pub get has to
hit the network? I'd like to make sure the message is really clear.

[blundell, 2015/04/09 11:53:41]

The inputs to the inner script are (1) the script itself [by default] and (2)
the target dir's pubspec.lock file [specified in line 31]. So the script will
re-run if either it changes or the pubspec.lock file changes.
Fixed this by having "pub get" run at "gclient sync" time.

+                           [
+                             rebase_dart_sdk_root,
+                             rebase_target_dir,
+                           ],
+                           "list lines",
+                           [ target_dir + "/pubspec.lock" ])
+
+      # Zip up all the pulled-in files relative to their location in the
+      # packages dir.
+      output = "$target_out_dir/$target_name.dartzip"
+      outputs = [
+        output,
+      ]
+      rebase_base_dir = rebase_target_dir + "/packages"
+      rebase_inputs = rebase_path(inputs, root_build_dir)
+      rebase_output = rebase_path(output, root_build_dir)
+      args = [
+        "--base-dir=$rebase_base_dir",
+        "--inputs=$rebase_inputs",
+        "--output=$rebase_output",
+      ]
+    }
+  }
+
   action("${package_target_name}_package") {
-    script = rebase_path("mojo/public/tools/gn/zip.py", ".", mojo_root)
+    script = rebase_path("mojo/public/tools/gn/zip.py", ".", mojo_sdk_root)
 
     inputs = invoker.sources
 
     deps = []
     zip_inputs = []
 
+    if (defined(invoker.uses_pub) && invoker.uses_pub) {
+      deps += [ ":${package_target_name}_pub_get" ]
+    }
+
     if (defined(invoker.deps)) {
       deps += invoker.deps
-      foreach(d, invoker.deps) {
+      foreach(d, deps) {
         dep_name = get_label_info(d, "name")
         dep_target_out_dir = get_label_info(d, "target_out_dir")
         zip_inputs += [ "$dep_target_out_dir/$dep_name.dartzip" ]
@@ -54,7 +95,8 @@ template("dart_package") {
   }
 
   action(target_name) {
-    script = rebase_path("mojo/public/tools/dart_analyze.py", ".", mojo_root)
+    script =
+        rebase_path("mojo/public/tools/dart_analyze.py", ".", mojo_sdk_root)
 
     sources = [
       package_output,
@@ -103,6 +145,9 @@ template("dart_packaged_application") {
     if (defined(invoker.deps)) {
       deps = invoker.deps
     }
+    if (defined(invoker.uses_pub)) {
+      uses_pub = invoker.uses_pub
+    }
     if (defined(invoker.mojom_deps)) {
       mojom_deps = invoker.mojom_deps
     }
@@ -112,7 +157,7 @@ template("dart_packaged_application") {
   }
 
   action(target_name) {
-    script = rebase_path("mojo/public/tools/prepend.py", ".", mojo_root)
+    script = rebase_path("mojo/public/tools/prepend.py", ".", mojo_sdk_root)
 
     input = package_output
     inputs = [