Add unit test for complex local logic

examples/named_cluster/main.tf

@@ -37,6 +37,15 @@ resource "azurerm_user_assigned_identity" "test" {
   resource_group_name = local.resource_group.name
 }
 
+# Just for demo purpose, not necessary to named cluster.
+resource "azurerm_log_analytics_workspace" "main" {
+  location            = local.resource_group.location
+  name                = "prefix-workspace"
+  resource_group_name = local.resource_group.name
+  retention_in_days   = 30
+  sku                 = "PerGB2018"
+}
+
 module "aks_cluster_name" {
   source = "../.."
 
@@ -50,6 +59,10 @@ module "aks_cluster_name" {
   identity_ids                         = [azurerm_user_assigned_identity.test.id]
   identity_type                        = "UserAssigned"
   log_analytics_workspace_enabled      = true
+  log_analytics_workspace = {
+    id   = azurerm_log_analytics_workspace.main.id
+    name = azurerm_log_analytics_workspace.main.name
+  }
   maintenance_window = {
     allowed = [
       {

locals.tf

@@ -0,0 +1,21 @@
+locals {
+  # Abstract the decision whether to create an Analytics Workspace or not.
+  create_analytics_solution  = var.log_analytics_workspace_enabled && var.log_analytics_solution_id == null
+  create_analytics_workspace = var.log_analytics_workspace_enabled && var.log_analytics_workspace == null
+  # Abstract the decision whether to use an Analytics Workspace supplied via vars, provision one ourselves or leave it null.
+  # This guarantees that local.log_analytics_workspace will contain a valid `id` and `name` IFF log_analytics_workspace_enabled
+  # is set to `true`.
+  log_analytics_workspace = var.log_analytics_workspace_enabled ? (
+    # The Log Analytics Workspace should be enabled:
+    var.log_analytics_workspace == null ? {
+      # `log_analytics_workspace_enabled` is `true` but `log_analytics_workspace` was not supplied.
+      # Create an `azurerm_log_analytics_workspace` resource and use that.
+      id   = local.azurerm_log_analytics_workspace_id
+      name = local.azurerm_log_analytics_workspace_name
+      } : {
+      # `log_analytics_workspace` is supplied. Let's use that.
+      id   = var.log_analytics_workspace.id
+      name = var.log_analytics_workspace.name
+    }
+  ) : null # Finally, the Log Analytics Workspace should be disabled.
+}

main.tf

@@ -1,27 +1,3 @@
-locals {
-
-  # Abstract the decision whether to create an Analytics Workspace or not.
-  create_analytics_solution  = var.log_analytics_workspace_enabled && var.log_analytics_solution_id == null
-  create_analytics_workspace = var.log_analytics_workspace_enabled && var.log_analytics_workspace == null
-  # Abstract the decision whether to use an Analytics Workspace supplied via vars, provision one ourselves or leave it null.
-  # This guarantees that local.log_analytics_workspace will contain a valid `id` and `name` IFF log_analytics_workspace_enabled
-  # is set to `true`.
-  log_analytics_workspace = var.log_analytics_workspace_enabled ? (
-    # The Log Analytics Workspace should be enabled:
-    var.log_analytics_workspace == null ? {
-      # `log_analytics_workspace_enabled` is `true` but `log_analytics_workspace` was not supplied.
-      # Create an `azurerm_log_analytics_workspace` resource and use that.
-      id   = azurerm_log_analytics_workspace.main[0].id
-      name = azurerm_log_analytics_workspace.main[0].name
-      } : {
-      # `log_analytics_workspace` is supplied. Let's use that.
-      id   = var.log_analytics_workspace.id
-      name = var.log_analytics_workspace.name
-    }
-  ) : null # Finally, the Log Analytics Workspace should be disabled.
-
-}
-
 data "azurerm_resource_group" "main" {
   name = var.resource_group_name
 }
@@ -255,6 +231,11 @@ resource "azurerm_log_analytics_workspace" "main" {
   tags                = var.tags
 }
 
+locals {
+  azurerm_log_analytics_workspace_id   = try(azurerm_log_analytics_workspace.main[0].id, null)
+  azurerm_log_analytics_workspace_name = try(azurerm_log_analytics_workspace.main[0].name, null)
+}
+
 resource "azurerm_log_analytics_solution" "main" {
   count = local.create_analytics_solution ? 1 : 0
 

test/unit/unit_test.go

@@ -0,0 +1,113 @@
+package unit
+
+import (
+	"testing"
+
+	test_helper "github.com/Azure/terraform-module-test-helper"
+	"github.com/gruntwork-io/terratest/modules/terraform"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDisableLogAnalyticsWorkspaceShouldNotCreateWorkspaceNorSolution(t *testing.T) {
+	vars := dummyRequiredVariables()
+	vars["log_analytics_workspace_enabled"] = false
+	test_helper.RunE2ETest(t, "../../", "unit-test-fixture", terraform.Options{
+		Upgrade: false,
+		Vars:    vars,
+	}, func(t *testing.T, output test_helper.TerraformOutput) {
+		createSolution, ok := output["create_analytics_solution"].(bool)
+		assert.True(t, ok)
+		assert.False(t, createSolution)
+		createWorkspace, ok := output["create_analytics_workspace"].(bool)
+		assert.True(t, ok)
+		assert.False(t, createWorkspace)
+		_, ok = output["log_analytics_workspace"]
+		assert.False(t, ok)
+	})
+}
+
+func TestLogAnalyticsWorkspaceEnabledButWorkspaceIdProvidedShouldNotCreateWorkspace(t *testing.T) {
+	vars := dummyRequiredVariables()
+	dummyWorkspace := struct {
+		id   string
+		name string
+	}{
+		id:   "dummyId",
+		name: "dummyName",
+	}
+	vars["log_analytics_workspace_enabled"] = true
+	vars["log_analytics_workspace"] = map[string]interface{}{
+		"id":   dummyWorkspace.id,
+		"name": dummyWorkspace.name,
+	}
+	test_helper.RunE2ETest(t, "../../", "unit-test-fixture", terraform.Options{
+		Upgrade: false,
+		Vars:    vars,
+	}, func(t *testing.T, output test_helper.TerraformOutput) {
+		createWorkspace, ok := output["create_analytics_workspace"].(bool)
+		assert.True(t, ok)
+		assert.False(t, createWorkspace)
+		workspace, ok := output["log_analytics_workspace"].(map[string]interface{})
+		assert.True(t, ok)
+		assert.Equal(t, dummyWorkspace.id, workspace["id"])
+		assert.Equal(t, dummyWorkspace.name, workspace["name"])
+	})
+}
+
+func TestLogAnalyticsWorkspaceEnabledNoWorkspaceProvidedShouldCreateWorkspace(t *testing.T) {
+	vars := dummyRequiredVariables()
+	expected := struct {
+		id   string
+		name string
+	}{
+		id:   "azurerm_log_analytics_workspace_id",
+		name: "azurerm_log_analytics_workspace_name",
+	}
+	vars["log_analytics_workspace_enabled"] = true
+	test_helper.RunE2ETest(t, "../../", "unit-test-fixture", terraform.Options{
+		Upgrade: false,
+		Vars:    vars,
+	}, func(t *testing.T, output test_helper.TerraformOutput) {
+		createWorkspace, ok := output["create_analytics_workspace"].(bool)
+		assert.True(t, ok)
+		assert.True(t, createWorkspace)
+		workspace, ok := output["log_analytics_workspace"].(map[string]interface{})
+		assert.True(t, ok)
+		assert.Equal(t, expected.id, workspace["id"])
+		assert.Equal(t, expected.name, workspace["name"])
+	})
+}
+
+func TestLogAnalyticsWorkspaceEnabledNoSolutionProvidedShouldCreateSolution(t *testing.T) {
+	vars := dummyRequiredVariables()
+	vars["log_analytics_workspace_enabled"] = true
+	test_helper.RunE2ETest(t, "../../", "unit-test-fixture", terraform.Options{
+		Upgrade: false,
+		Vars:    vars,
+	}, func(t *testing.T, output test_helper.TerraformOutput) {
+		createSolution, ok := output["create_analytics_solution"].(bool)
+		assert.True(t, ok)
+		assert.True(t, createSolution)
+	})
+}
+
+func TestLogAnalyticsWorkspaceEnabledSolutionProvidedShouldNotCreateSolution(t *testing.T) {
+	vars := dummyRequiredVariables()
+	vars["log_analytics_workspace_enabled"] = true
+	vars["log_analytics_solution_id"] = "dummySolutionId"
+	test_helper.RunE2ETest(t, "../../", "unit-test-fixture", terraform.Options{
+		Upgrade: false,
+		Vars:    vars,
+	}, func(t *testing.T, output test_helper.TerraformOutput) {
+		createSolution, ok := output["create_analytics_solution"].(bool)
+		assert.True(t, ok)
+		assert.False(t, createSolution)
+	})
+}
+
+func dummyRequiredVariables() map[string]interface{} {
+	return map[string]interface{}{
+		"prefix":              "foo",
+		"resource_group_name": "bar",
+	}
+}

unit-test-fixture/alt_locals.tf

@@ -0,0 +1,4 @@
+locals {
+  azurerm_log_analytics_workspace_id   = "azurerm_log_analytics_workspace_id"
+  azurerm_log_analytics_workspace_name = "azurerm_log_analytics_workspace_name"
+}

unit-test-fixture/locals.tf

@@ -0,0 +1 @@
+../locals.tf

unit-test-fixture/outputs.tf

@@ -0,0 +1,11 @@
+output "create_analytics_solution" {
+  value = local.create_analytics_solution
+}
+
+output "create_analytics_workspace" {
+  value = local.create_analytics_workspace
+}
+
+output "log_analytics_workspace" {
+  value = local.log_analytics_workspace
+}

unit-test-fixture/variables.tf

@@ -0,0 +1 @@
+../variables.tf