global: allow setting of copy instructions per bundle

* because copy instructions may vary based on the exact JS code in
  question (e.g. TinyMCE and PDF.js), they are placed in bundles

pywebpack/bundle.py

@@ -21,6 +21,7 @@ def __init__(
         devDependencies=None,
         peerDependencies=None,
         aliases=None,
+        copy=None,
     ):
         """Initialize webpack bundle.
 
@@ -32,6 +33,7 @@ def __init__(
         :param devDependencies: npm dev dependencies.
         :param peerDependencies: npm peer dependencies.
         :param aliases: Webpack resolver aliases.
+        :param copy: Instructions to copy assets somewhere else.
         """
         self.path = path
         self.entry = entry or {}
@@ -41,3 +43,4 @@ def __init__(
             "peerDependencies": peerDependencies or {},
         }
         self.aliases = aliases or {}
+        self.copy = copy or []

pywebpack/project.py

@@ -238,11 +238,28 @@ def entry(self):
             entries["entries"].update(bundle.entry)
         return entries["entries"]
 
+    @property
+    def copy(self):
+        """Get instructions for copying assets around."""
+        copy_instructions = []
+        for bundle in self.bundles:
+            for copy in bundle.copy:
+                if set(copy.keys()) != {"from", "to"}:
+                    raise RuntimeError(
+                        f"Invalid copy instruction: {copy}. "
+                        "Requires exactly 'to' and 'from' keys to be present."
+                    )
+
+                # NOTE: the validation check is performed in the JS build step
+                copy_instructions.append(copy)
+
+        return copy_instructions
+
     @property
     def config(self):
         """Inject webpack entry points from bundles."""
         config = super(WebpackBundleProject, self).config
-        config.update({"entry": self.entry, "aliases": self.aliases})
+        config.update({"entry": self.entry, "aliases": self.aliases, "copy": self.copy})
         return config
 
     @property

tests/test_pywebpack.py

@@ -226,13 +226,15 @@ def test_bundleproject(builddir, bundledir, destdir):
     """Test bundle project."""
     entry = {"app": "./index.js"}
     aliases = {"@app": "index.js"}
+    copy = [{"from": "./source/", "to": "./target/"}]
     bundle = WebpackBundle(
         bundledir,
         entry=entry,
         dependencies={
             "lodash": "~4",
         },
         aliases=aliases,
+        copy=copy,
     )
     project = WebpackBundleProject(
         working_dir=destdir,
@@ -243,7 +245,12 @@ def test_bundleproject(builddir, bundledir, destdir):
 
     assert project.bundles == [bundle]
     assert project.entry == entry
-    assert project.config == {"entry": entry, "test": True, "aliases": aliases}
+    assert project.config == {
+        "entry": entry,
+        "test": True,
+        "aliases": aliases,
+        "copy": copy,
+    }
     assert project.dependencies == {
         "dependencies": {
             "lodash": "~4",