Do not build the js assets if the static directory is populated.

In making the conda-forge package, we realized when building a wheel from the sdist package did not work. NodeJS compilation really only works in the context of this repo.

This change makes it so that static assets are not rebuilt in the setup.py commands if they already exist.

Author: jasongrout

jupyterlab_widgets/MANIFEST.in

@@ -8,8 +8,8 @@ include ts*.json
 graft jupyterlab_widgets/static
 
 # Javascript files
-graft src
-graft style
+prune src
+prune style
 prune **/node_modules
 prune lib
 

jupyterlab_widgets/setup.py

@@ -24,7 +24,6 @@
 
 # Representative files that should exist after a successful build
 jstargets = [
-    os.path.join(HERE, "lib", "index.js"),
     os.path.join(HERE, name, "static", "package.json"),
 ]
 
@@ -46,10 +45,15 @@
     data_files_spec=data_files_spec
 )
 
-cmdclass["jsdeps"] = combine_commands(
-    install_npm(HERE, build_cmd="build", npm=["jlpm"]),
-    ensure_targets(jstargets),
-)
+# if the static assets already exist, do not invoke npm so we can make a wheel
+# from the sdist package, since the npm build really only works from this
+# repo.
+jsbuild = []
+if all(os.path.exists(f) for f in jstargets):
+    jsbuild.append(install_npm(HERE, build_cmd="build", npm=["jlpm"]))
+jsbuild.append(ensure_targets(jstargets))
+
+cmdclass["jsdeps"] = combine_commands(*jsbuild)
 
 with open("README.md", "r") as fh:
     long_description = fh.read()