[ci,dx] Add unit tests for cozy-lib (#1643)

## What this PR does

The cozy-lib library package got complicated enough to warrant its own
unit tests. Since unit tests are a "good thing" (tm), a somewhat generic
framework for running all kinds of unit tests was introduced into the CI
pipeline and Makefile targets. For now all it runs is `make test`
against the `packages/{library,apps,system,extra}/*` directories,
wherever a `test` target is present in the Makefile, and for now this is
only for the `cozy-lib` Helm library chart.

### Release note

```release-note
[ci,dx] Introduce a scaffold for running unit tests locally and in CI
and add the first unit tests for the cozy-lib helper Helm chart.
```


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Tests**
* Integrated Helm chart unit tests into the CI/CD pipeline for automated
validation.
* Established test infrastructure for cozy-lib package with test cases
for quota configuration and resource validation.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

.github/workflows/pull-requests.yaml

@@ -33,6 +33,9 @@ jobs:
           fetch-depth: 0
           fetch-tags: true
 
+      - name: Run unit tests
+        run: make unit-tests
+
       - name: Set up Docker config
         run: |
           if [ -d ~/.docker ]; then

Makefile

@@ -1,4 +1,4 @@
-.PHONY: manifests repos assets
+.PHONY: manifests repos assets unit-tests helm-unit-tests
 
 build-deps:
 	@command -V find docker skopeo jq gh helm > /dev/null
@@ -46,6 +46,11 @@ test:
 	make -C packages/core/testing apply
 	make -C packages/core/testing test
 
+unit-tests: helm-unit-tests
+
+helm-unit-tests:
+	hack/helm-unit-tests.sh
+
 prepare-env:
 	make -C packages/core/testing apply
 	make -C packages/core/testing prepare-cluster

hack/helm-unit-tests.sh

@@ -0,0 +1,59 @@
+#!/bin/sh
+set -eu
+
+# Script to run unit tests for all Helm charts.
+# It iterates through directories in packages/apps, packages/extra,
+# packages/system, and packages/library and runs the 'test' Makefile
+# target if it exists.
+
+FAILED_DIRS_FILE="$(mktemp)"
+trap 'rm -f "$FAILED_DIRS_FILE"' EXIT
+
+tests_found=0
+
+check_and_run_test() {
+    dir="$1"
+    makefile="$dir/Makefile"
+
+    if [ ! -f "$makefile" ]; then
+        return 0
+    fi
+
+    if make -C "$dir" -n test >/dev/null 2>&1; then
+        echo "Running tests in $dir"
+        tests_found=$((tests_found + 1))
+        if ! make -C "$dir" test; then
+            printf '%s\n' "$dir" >> "$FAILED_DIRS_FILE"
+            return 1
+        fi
+    fi
+
+    return 0
+}
+
+for package_dir in packages/apps packages/extra packages/system packages/library; do
+    if [ ! -d "$package_dir" ]; then
+        echo "Warning: Directory $package_dir does not exist, skipping..." >&2
+        continue
+    fi
+
+    for dir in "$package_dir"/*; do
+        [ -d "$dir" ] || continue
+        check_and_run_test "$dir" || true
+    done
+done
+
+if [ "$tests_found" -eq 0 ]; then
+    echo "No directories with 'test' Makefile targets found."
+    exit 0
+fi
+
+if [ -s "$FAILED_DIRS_FILE" ]; then
+    echo "ERROR: Tests failed in the following directories:" >&2
+    while IFS= read -r dir; do
+        echo "  - $dir" >&2
+    done < "$FAILED_DIRS_FILE"
+    exit 1
+fi
+
+echo "All Helm unit tests passed."

packages/library/cozy-lib/Makefile

@@ -4,3 +4,5 @@ include ../../../scripts/package.mk
 generate:
 	cozyvalues-gen -v values.yaml -s values.schema.json -r README.md
 
+test:
+	$(MAKE) -C ../../tests/cozy-lib-tests/ test

packages/tests/cozy-lib-tests/.helmignore

@@ -0,0 +1,23 @@
+# Patterns to ignore when building packages.
+# This supports shell glob matching, relative path matching, and
+# negation (prefixed with !). Only one pattern per line.
+.DS_Store
+# Common VCS dirs
+.git/
+.gitignore
+.bzr/
+.bzrignore
+.hg/
+.hgignore
+.svn/
+# Common backup files
+*.swp
+*.bak
+*.tmp
+*.orig
+*~
+# Various IDEs
+.project
+.idea/
+*.tmproj
+.vscode/

packages/tests/cozy-lib-tests/Chart.yaml

@@ -0,0 +1,24 @@
+apiVersion: v2
+name: quota
+description: Testing chart for cozy-lib
+
+# A chart can be either an 'application' or a 'library' chart.
+#
+# Application charts are a collection of templates that can be packaged into versioned archives
+# to be deployed.
+#
+# Library charts provide useful utilities or functions for the chart developer. They're included as
+# a dependency of application charts to inject those utilities and functions into the rendering
+# pipeline. Library charts do not define any templates and therefore cannot be deployed.
+type: application
+
+# This is the chart version. This version number should be incremented each time you make changes
+# to the chart and its templates, including the app version.
+# Versions are expected to follow Semantic Versioning (https://semver.org/)
+version: 0.1.0
+
+# This is the version number of the application being deployed. This version number should be
+# incremented each time you make changes to the application. Versions are not expected to
+# follow Semantic Versioning. They should reflect the version the application is using.
+# It is recommended to use it with quotes.
+appVersion: "1.16.0"

packages/tests/cozy-lib-tests/Makefile

@@ -0,0 +1,2 @@
+test:
+	helm unittest .

packages/tests/cozy-lib-tests/charts/cozy-lib

@@ -0,0 +1 @@
+../../../library/cozy-lib

packages/tests/cozy-lib-tests/templates/tests/quota.yaml

@@ -0,0 +1,8 @@
+apiVersion: v1
+kind: ResourceQuota
+metadata:
+  name: {{ .Release.Name }}
+spec:
+{{- with .Values.quota }}
+  hard: {{- include "cozy-lib.resources.flatten" (list . $) | nindent 4 }}
+{{- end }}

packages/tests/cozy-lib-tests/tests/quota_test.yaml

@@ -0,0 +1,30 @@
+# ./tests/quota_test.yaml
+suite: quota helper
+
+templates:
+  - templates/tests/quota.yaml
+
+tests:
+  - it: correctly interprets special kubernetes quota types
+    values:
+      - quota_values.yaml
+
+    release:
+      name: myrelease
+      namespace: default
+      revision: 1
+      isUpgrade: false
+
+    asserts:
+      - equal:
+          path: spec.hard["limits.cpu"]
+          value: "2"
+
+      - equal:
+          path: spec.hard["requests.cpu"]
+          value: "0.2"
+
+      - equal:
+          path: spec.hard["services.loadbalancers"]
+          value: "2"
+

packages/tests/cozy-lib-tests/tests/quota_values.yaml

@@ -0,0 +1,3 @@
+quota:
+  services.loadbalancers: "2"
+  cpu: "2"