document how to test unpublished charts

README.md

@@ -1,4 +1,27 @@
-### Run tests locally
+# Argo Helm Charts
+
+This repository contains Helm charts that we use in ArgoCD / Argus.
+
+The `stack` chart is the standard chart for used when deploying an Argus application.
+
+### Running tests locally
+
 1. `helm plugin install https://github.com/helm-unittest/helm-unittest.git`
 2. from the root: run `helm unittest stack`
 3. run `helm unittest -u stack --debugPlugin` to see the templates generated by the unit tests
+
+### Testing an un-published chart in Argus
+
+You can test a chart that has not been published.
+
+Suppose you want to test some local changes of the stack helm chart in the `argus-example-app`. To do so you would:
+
+1. Clone the `argus-example-app` repository
+1. Change the `.infra/rdev/Chart.yaml` in the `argus-example-app` to point to the local directory
+  - set the `repository` of the `stack` chart dependency to `file://<relative path to argo-helm-charts/stack/ directory>`
+1. Run `helm dependency update` from a terminal in the `argus-example-app` repository
+1. Create a new branch then commit and push the changes to the `argus-example-app` repository
+  - This should include your changes to `.infra/rdev/Chart.yaml`, the newly created `.infra/rdev/Chart.lock`, and the `.infra/rdev/charts/stack-<X.Y.Z>.tgz` file
+1. Create a PR in the `argus-example-app` repository and create a stack in Argus using the `stack` label on the PR
+
+NOTE: Do not merge `.infra/rdev/Chart.lock` or `.infra/rdev/charts/stack-<X.Y.Z>.tgz` into the main branch. These files should only be used for testing purposes.