chore: add helm tests and update ci to check for changes

.github/workflows/ci.yaml

@@ -76,12 +76,31 @@ jobs:
       - name: Run integration tests
         run: go test -tags=integration -v -timeout=8m ./...
 
+  helm-test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
+      - name: Setup Go
+        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6
+        with:
+          go-version: "~1.26"
+      - name: Setup Helm
+        uses: azure/setup-helm@f0accbfd55e3332a28f721b8202b1016cecf90d5 # v5
+        with:
+          version: "v3.18.3"
+      - name: Run Helm chart tests
+        run: go test ./helm/tests/...
+      - name: Check for unstaged files
+        run: ./scripts/check_unstaged.sh
+
   required:
     runs-on: ubuntu-latest
     needs:
       - test
       - lint
       - integration-test
+      - helm-test
     # Allow this job to run even if the needed jobs fail, are skipped or
     # cancelled.
     if: always()

helm/tests/chart_test.go

@@ -0,0 +1,198 @@
+package tests // nolint: testpackage
+
+import (
+	"bytes"
+	"flag"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"golang.org/x/xerrors"
+)
+
+// These tests run `helm template` with the values file specified in each test
+// and compare the output to the contents of the corresponding golden file.
+// All values and golden files are located in the `testdata` directory.
+// To update golden files, run `go test . -update`.
+
+// updateGoldenFiles is a flag that can be set to update golden files.
+var updateGoldenFiles = flag.Bool("update", false, "Update golden files")
+
+var namespaces = []string{
+	"default",
+	"coder",
+}
+
+var testCases = []testCase{
+	{
+		name:          "default_values",
+		expectedError: "",
+	},
+	{
+		name:          "all_values",
+		expectedError: "",
+	},
+}
+
+type testCase struct {
+	name          string // Name of the test case. This is used to control which values and golden file are used.
+	namespace     string // Namespace is the name of the namespace the resources should be generated within
+	expectedError string // Expected error from running `helm template`.
+}
+
+func (tc testCase) valuesFilePath() string {
+	return filepath.Join("./testdata", tc.name+".yaml")
+}
+
+func (tc testCase) goldenFilePath() string {
+	if tc.namespace == "default" {
+		return filepath.Join("./testdata", tc.name+".golden")
+	}
+
+	return filepath.Join("./testdata", tc.name+"_"+tc.namespace+".golden")
+}
+
+func inCI() bool { return os.Getenv("CI") != "" }
+
+func TestRenderChart(t *testing.T) {
+	t.Parallel()
+	if *updateGoldenFiles {
+		t.Skip("Golden files are being updated. Skipping test.")
+	}
+	if inCI() {
+		switch runtime.GOOS {
+		case "windows", "darwin":
+			t.Skip("Skipping tests on Windows and macOS in CI")
+		}
+	}
+
+	// Ensure that Helm is available in $PATH
+	helmPath := lookupHelm(t)
+	err := updateHelmDependencies(t, helmPath, "..")
+	require.NoError(t, err, "failed to build Helm dependencies")
+
+	for _, tc := range testCases {
+		for _, ns := range namespaces {
+			tc.namespace = ns
+
+			t.Run(tc.namespace+"/"+tc.name, func(t *testing.T) {
+				t.Parallel()
+
+				// Ensure that the values file exists.
+				valuesFilePath := tc.valuesFilePath()
+				if _, err := os.Stat(valuesFilePath); os.IsNotExist(err) {
+					t.Fatalf("values file %q does not exist", valuesFilePath)
+				}
+
+				// Run helm template with the values file.
+				templateOutput, err := runHelmTemplate(t, helmPath, "..", valuesFilePath, tc.namespace)
+				if tc.expectedError != "" {
+					require.Error(t, err, "helm template should have failed")
+					require.Contains(t, templateOutput, tc.expectedError, "helm template output should contain expected error")
+				} else {
+					require.NoError(t, err, "helm template should not have failed")
+					require.NotEmpty(t, templateOutput, "helm template output should not be empty")
+					goldenFilePath := tc.goldenFilePath()
+					goldenBytes, err := os.ReadFile(goldenFilePath)
+					require.NoError(t, err, "failed to read golden file %q", goldenFilePath)
+
+					// Remove carriage returns to make tests pass on Windows.
+					goldenBytes = bytes.ReplaceAll(goldenBytes, []byte("\r"), []byte(""))
+					expected := string(goldenBytes)
+
+					require.NoError(t, err, "failed to load golden file %q")
+					require.Equal(t, expected, templateOutput)
+				}
+			})
+		}
+	}
+}
+
+func TestUpdateGoldenFiles(t *testing.T) {
+	t.Parallel()
+	if !*updateGoldenFiles {
+		t.Skip("Run with -update to update golden files")
+	}
+
+	helmPath := lookupHelm(t)
+	err := updateHelmDependencies(t, helmPath, "..")
+	require.NoError(t, err, "failed to build Helm dependencies")
+
+	for _, tc := range testCases {
+		if tc.expectedError != "" {
+			t.Logf("skipping test case %q with render error", tc.name)
+			continue
+		}
+
+		for _, ns := range namespaces {
+			tc.namespace = ns
+
+			valuesPath := tc.valuesFilePath()
+			templateOutput, err := runHelmTemplate(t, helmPath, "..", valuesPath, tc.namespace)
+			if err != nil {
+				t.Logf("error running `helm template -f %q`: %v", valuesPath, err)
+				t.Logf("output: %s", templateOutput)
+			}
+			require.NoError(t, err, "failed to run `helm template -f %q`", valuesPath)
+
+			goldenFilePath := tc.goldenFilePath()
+			err = os.WriteFile(goldenFilePath, []byte(templateOutput), 0o644) // nolint:gosec
+			require.NoError(t, err, "failed to write golden file %q", goldenFilePath)
+		}
+	}
+	t.Log("Golden files updated. Please review the changes and commit them.")
+}
+
+// updateHelmDependencies runs `helm dependency update .` on the given chartDir.
+func updateHelmDependencies(t testing.TB, helmPath, chartDir string) error {
+	// Remove charts/ from chartDir if it exists.
+	err := os.RemoveAll(filepath.Join(chartDir, "charts"))
+	if err != nil {
+		return xerrors.Errorf("failed to remove charts/ directory: %w", err)
+	}
+
+	// Regenerate the chart dependencies.
+	cmd := exec.Command(helmPath, "dependency", "update", "--skip-refresh", ".")
+	cmd.Dir = chartDir
+	t.Logf("exec command: %v", cmd.Args)
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return xerrors.Errorf("failed to run `helm dependency build`: %w\noutput: %s", err, out)
+	}
+
+	return nil
+}
+
+// runHelmTemplate runs helm template on the given chart with the given values and
+// returns the raw output.
+func runHelmTemplate(t testing.TB, helmPath, chartDir, valuesFilePath, namespace string) (string, error) {
+	// Ensure that valuesFilePath exists
+	if _, err := os.Stat(valuesFilePath); err != nil {
+		return "", xerrors.Errorf("values file %q does not exist: %w", valuesFilePath, err)
+	}
+
+	cmd := exec.Command(helmPath, "template", chartDir, "-f", valuesFilePath, "--namespace", namespace)
+	t.Logf("exec command: %v", cmd.Args)
+	out, err := cmd.CombinedOutput()
+	return string(out), err
+}
+
+// lookupHelm ensures that Helm is available in $PATH and returns the path to the
+// Helm executable.
+func lookupHelm(t testing.TB) string {
+	helmPath, err := exec.LookPath("helm")
+	if err != nil {
+		t.Fatalf("helm not found in $PATH: %v", err)
+		return ""
+	}
+	t.Logf("Using helm at %q", helmPath)
+	return helmPath
+}
+
+func TestMain(m *testing.M) {
+	flag.Parse()
+	os.Exit(m.Run())
+}