Make update-template.sh more robust to deletions and changes to files (#217)

## Ticket

Resolves #196

## Changes

- Copies the changes made in
navapbc/template-infra#352

Author: sawyerh

template-only-bin/download-and-install-template.sh

@@ -7,5 +7,10 @@ git clone --single-branch --branch main --depth 1 [email protected]:navapbc/templat
 echo "Install template"
 ./template-application-flask/template-only-bin/install-template.sh
 
+# Store template version in a file
+cd template-application-flask
+git rev-parse HEAD >../.template-flask-version
+cd -
+
 echo "Clean up template-application-flask folder"
 rm -fr template-application-flask

template-only-bin/install-template.sh

@@ -1,15 +1,16 @@
 #!/bin/bash
 #
-# This script installs template-application-flask to your project. Run
+# This script installs the template-application-flask to your project. Run
 # This script from your project's root directory.
-set -euo pipefail
+set -euox pipefail
 
 CUR_DIR=$(pwd)
 SCRIPT_DIR=$(dirname $0)
 TEMPLATE_DIR="$SCRIPT_DIR/.."
 
 echo "Copy files from template-application-flask"
 cd $TEMPLATE_DIR
+# Note: Keep this list of paths in sync with INCLUDE_PATHS in update-template.sh
 cp -r \
   .github \
   .dockleconfig \
@@ -21,4 +22,5 @@ cp -r \
 cd -
 
 echo "Remove files relevant only to template development"
+# Note: Keep this list of paths in sync with EXCLUDE_OPT in update-template.sh
 rm .github/workflows/template-only-*

template-only-bin/update-template.sh

@@ -1,10 +1,46 @@
 #!/bin/bash
-#
+# -----------------------------------------------------------------------------
 # This script updates template-application-flask in your project. Run
 # This script from your project's root directory.
+#
+# Positional parameters:
+#   TARGET_VERSION (optional) – the version of template-application-flask to upgrade to.
+#     Defaults to main.
+# -----------------------------------------------------------------------------
 set -euo pipefail
 
-SCRIPT_DIR=$(dirname $0)
+TARGET_VERSION=${1:-"main"}
+
+CURRENT_VERSION=$(cat .template-flask-version)
+
+echo "Clone template-application-flask"
+git clone https://github.com/navapbc/template-application-flask.git
+
+echo "Creating patch"
+cd template-application-flask
+git checkout $TARGET_VERSION
+
+# Get version hash to update .template-flask-version after patch is successful
+TARGET_VERSION_HASH=$(git rev-parse HEAD)
+
+# Note: Keep this list in sync with the files copied in install-template.sh
+INCLUDE_PATHS=" \
+  github \
+  .dockleconfig \
+  .hadolint.yaml \
+  app \
+  docker-compose.yml \
+  docs"
+git diff $CURRENT_VERSION $TARGET_VERSION -- $INCLUDE_PATHS >patch
+cd -
+
+echo "Applying patch"
+# Note: Keep this list in sync with the removed files in install-template.sh
+EXCLUDE_OPT="--exclude=.github/workflows/template-only-*"
+git apply $EXCLUDE_OPT --allow-empty template-application-flask/patch
+
+echo "Saving new template version to .template-application-flask"
+echo $TARGET_VERSION_HASH >.template-flask-version
 
-echo "Install template"
-$SCRIPT_DIR/install-template.sh
+echo "Clean up template-application-flask folder"
+rm -fr template-application-flask