Add more unit tests to helm chart (#10731)

* Add more unit tests to helm chart

Signed-off-by: Stavros Foteinopoulos <stafot@gmail.com>

* Apply suggestions from code review

Co-authored-by: Marco Ebert <marco_ebert@icloud.com>

* Apply suggestions from code review

Co-authored-by: Marco Ebert <marco_ebert@icloud.com>

* Apply suggestions from code review

Co-authored-by: Marco Ebert <marco_ebert@icloud.com>

* Use upstream helm-unittest repository

Signed-off-by: Stavros Foteinopoulos <stafot@gmail.com>

* Remove non existing value from controller unittest

Signed-off-by: Stavros Foteinopoulos <stafot@gmail.com>

* fix unit test

Signed-off-by: Stavros Foteinopoulos <stafot@gmail.com>

* Apply suggestions from code review

Co-authored-by: Marco Ebert <marco_ebert@icloud.com>

* Apply suggestions from code review

Co-authored-by: Marco Ebert <marco_ebert@icloud.com>

---------

Signed-off-by: Stavros Foteinopoulos <stafot@gmail.com>
Co-authored-by: Marco Ebert <marco_ebert@icloud.com>

charts/ingress-nginx/tests/controller-configmap-proxyheaders_test.yaml

@@ -0,0 +1,27 @@
+suite: Controller > ConfigMap > Proxy Headers
+templates:
+  - controller-configmap-proxyheaders.yaml
+
+tests:
+  - it: should not create a ConfigMap if `controller.proxySetHeaders` is not set
+    set:
+      controller.proxySetHeaders: null
+    asserts:
+      - hasDocuments:
+          count: 0
+
+  - it: should create a ConfigMap if `controller.proxySetHeaders` is set
+    set:
+      controller.proxySetHeaders:
+        X-Custom-Header: Value
+    asserts:
+      - hasDocuments:
+          count: 1
+      - isKind:
+          of: ConfigMap
+      - equal:
+          path: metadata.name
+          value: RELEASE-NAME-ingress-nginx-custom-proxy-headers
+      - equal:
+          path: data.X-Custom-Header
+          value: Value