Add integration scaffolding script (#26777)

* Add integration scaffolding script

* Make easier to develop

* Update py.test -> pytest

script/scaffold/__main__.py

@@ -0,0 +1,56 @@
+"""Validate manifests."""
+from pathlib import Path
+import subprocess
+import sys
+
+from . import gather_info, generate, error, model
+
+
+def main():
+    """Scaffold an integration."""
+    if not Path("requirements_all.txt").is_file():
+        print("Run from project root")
+        return 1
+
+    print("Creating a new integration for Home Assistant.")
+
+    if "--develop" in sys.argv:
+        print("Running in developer mode. Automatically filling in info.")
+        print()
+
+        info = model.Info(
+            domain="develop",
+            name="Develop Hub",
+            codeowner="@developer",
+            requirement="aiodevelop==1.2.3",
+        )
+    else:
+        try:
+            info = gather_info.gather_info()
+        except error.ExitApp as err:
+            print()
+            print(err.reason)
+            return err.exit_code
+
+    generate.generate(info)
+
+    print("Running hassfest to pick up new codeowner and config flow.")
+    subprocess.run("python -m script.hassfest", shell=True)
+    print()
+
+    print("Running tests")
+    print(f"$ pytest tests/components/{info.domain}")
+    if (
+        subprocess.run(f"pytest tests/components/{info.domain}", shell=True).returncode
+        != 0
+    ):
+        return 1
+    print()
+
+    print(f"Successfully created the {info.domain} integration!")
+
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())