chore(common): add makefile for test scripts

Author: nickchecan

Makefile

@@ -0,0 +1,27 @@
+APP_DIR := test/my-app
+BUILD_DIR := /tmp/uv-bp-build
+CACHE_DIR := /tmp/uv-bp-cache
+ENV_DIR := /tmp/uv-bp-env
+ROOT_DIR := $(CURDIR)
+BUILDPACK_DIR := $(ROOT_DIR)
+PYTHON_BIN ?= python3
+
+.PHONY: test-buildpack clean-test-buildpack start-local
+
+# Reset the temporary staging directories used for local buildpack testing.
+clean-test-buildpack:
+	rm -rf $(BUILD_DIR) $(CACHE_DIR) $(ENV_DIR)
+
+# Run the sample app through detect, compile, and release using the same
+# temporary directories each time so local testing is repeatable.
+test-buildpack: clean-test-buildpack
+	mkdir -p $(BUILD_DIR) $(CACHE_DIR) $(ENV_DIR)
+	cp -R $(APP_DIR)/. $(BUILD_DIR)
+	cd $(APP_DIR) && ../../bin/detect
+	$(BUILDPACK_DIR)/bin/compile $(BUILD_DIR) $(CACHE_DIR) $(ENV_DIR)
+	cd $(BUILD_DIR) && /bin/bash -lc 'source .profile.d/python.sh && $(PYTHON_BIN) -c "import fastapi; print(fastapi.__version__)"'
+	cd $(BUILD_DIR) && $(BUILDPACK_DIR)/bin/release
+
+# Start the staged sample app locally using the dependencies prepared by `test-buildpack`.
+start-local:
+	cd $(BUILD_DIR) && /bin/bash -lc 'source .profile.d/python.sh && $(PYTHON_BIN) main.py'

README.md

@@ -2,3 +2,32 @@
 
 The current cloud foundry [python-buildpack](https://github.com/cloudfoundry/python-buildpack) doesn't support modern python tools, such as [uv](https://docs.astral.sh/uv/), so I created this custom buildpack to bridge the gap.
 
+## Testing Locally
+
+Run the buildpack test flow from the repository root:
+
+```sh
+make test-buildpack
+```
+
+This command:
+
+- stages `test/my-app` into a temporary build directory
+- runs `bin/detect`
+- runs `bin/compile`
+- verifies the staged dependencies can be imported
+- prints the `bin/release` output
+
+If you want to remove the temporary staging directories before or after a run:
+
+```sh
+make clean-test-buildpack
+```
+
+If you want to start the staged sample app locally after `make test-buildpack` succeeds:
+
+```sh
+make start-local
+```
+
+Then open `http://127.0.0.1:8000/`.