Ensure the lambda is rebuilt if, and only if, it needs to be.

Author: acerathereinspirative-nhs-nvir

Makefile

@@ -3,6 +3,8 @@
 # ==============================================================================
 include scripts/init.mk
 
+MAKE_DIR := $(abspath $(shell pwd))
+
 #Installs dependencies using poetry.
 install-python:
 	poetry install
@@ -39,13 +41,15 @@ publish: clean
 #Files to loop over in release
 _dist_include="pytest.ini poetry.lock poetry.toml pyproject.toml Makefile build/. tests"
 
-
 # Example CI/CD targets are: dependencies, build, publish, deploy, clean, etc.
 
 dependencies: # Install dependencies needed to build and test the project @Pipeline
 	scripts/dependencies.sh
 
-build: # Build lambda in dist
+.PHONY: build
+build: dist/lambda.zip # Build lambda.zip in dist/
+
+dist/lambda.zip: $(MAKE_DIR)/pyproject.toml $(MAKE_DIR)/poetry.lock $(shell find src -type f)
 	poetry build-lambda -vv
 
 deploy: # Deploy the project artefact to the target environment @Pipeline

tests/integration/conftest.py

@@ -1,6 +1,7 @@
 import json
 import logging
 import os
+import subprocess
 from collections.abc import Generator
 from pathlib import Path
 from typing import TYPE_CHECKING, Any
@@ -131,9 +132,16 @@ def iam_role(iam_client: BaseClient) -> Generator[str]:
 
 
 @pytest.fixture(scope="session")
-def flask_function(lambda_client: BaseClient, iam_role: str) -> Generator[str]:
+def lambda_zip() -> Path:
+    build_result = subprocess.run(["make", "build"], capture_output=True, text=True, check=False)
+    assert build_result.returncode == 0, f"'make build' failed: {build_result.stderr}"
+    return Path("dist/lambda.zip")
+
+
+@pytest.fixture(scope="session")
+def flask_function(lambda_client: BaseClient, iam_role: str, lambda_zip: Path) -> Generator[str]:
     function_name = "eligibility_signposting_api"
-    with Path("dist/lambda.zip").open("rb") as zipfile:
+    with lambda_zip.open("rb") as zipfile:
         lambda_client.create_function(
             FunctionName=function_name,
             Runtime="python3.13",