perf: Short-circuit deployment if ARM template hasn't changed (#239)

This checks the previously deployed template (including parameters/values) to see if the generated template has changed since the last deployment. If it has not changed, it will not deploy the ARM template. Since many cases will be code changes, this will drastically increase the speed of the average deployment.

Resolves [AB#789]

Author: tbarlow12

package-lock.json

@@ -47,6 +47,7 @@
     "@azure/ms-rest-nodeauth": "^1.0.1",
     "@azure/storage-blob": "^10.3.0",
     "axios": "^0.18.0",
+    "deep-equal": "^1.0.1",
     "js-yaml": "^3.13.1",
     "jsonpath": "^1.0.1",
     "lodash": "^4.16.6",

package.json

@@ -1,12 +1,13 @@
 import Serverless from "serverless";
 import { MockFactory } from "../test/mockFactory";
 import { ArmService } from "./armService";
-import { ArmResourceTemplate, ArmTemplateType } from "../models/armTemplates";
+import { ArmResourceTemplate, ArmTemplateType, ArmDeployment } from "../models/armTemplates";
 import { ArmTemplateConfig, ServerlessAzureOptions } from "../models/serverless";
 import mockFs from "mock-fs";
 import jsonpath from "jsonpath";
 import { Deployments } from "@azure/arm-resources";
 import { Deployment } from "@azure/arm-resources/esm/models";
+import { ResourceService } from "./resourceService";
 
 describe("Arm Service", () => {
   let sls: Serverless
@@ -29,6 +30,13 @@ describe("Arm Service", () => {
     };
 
     service = createService();
+    ResourceService.prototype.getDeployments = jest.fn(() => MockFactory.createTestDeployments()) as any;
+    ResourceService.prototype.getDeploymentTemplate = jest.fn(() => {
+      return {
+        template: MockFactory.createTestArmTemplate()
+      }
+    }) as any;
+
   })
 
   afterEach(() => {
@@ -151,6 +159,51 @@ describe("Arm Service", () => {
       Deployments.prototype.createOrUpdate = jest.fn(() => Promise.resolve(null));
     });
 
+    it("Does not deploy if previously deployed template is the same", async () => {
+      const deployment: ArmDeployment = {
+        parameters: MockFactory.createTestParameters(false),
+        template: MockFactory.createTestArmTemplate()
+      };
+      await service.deployTemplate(deployment);
+      expect(Deployments.prototype.createOrUpdate).not.toBeCalled()
+    });
+
+    it("Calls deploy if parameters have changed from deployed template", async () => {
+      const deployment: ArmDeployment = {
+        parameters: MockFactory.createTestParameters(false),
+        template: MockFactory.createTestArmTemplate()
+      };
+      deployment.parameters.param1 = "3"
+      await service.deployTemplate(deployment);
+      expect(Deployments.prototype.createOrUpdate).toBeCalled();
+    });
+
+    it("Calls deploy if previously deployed template is different", async () => {
+      ResourceService.prototype.getDeploymentTemplate = jest.fn(() => {
+        return {
+          template: {}
+        }
+      }) as any;
+      const deployment: ArmDeployment = {
+        parameters: MockFactory.createTestParameters(false),
+        template: MockFactory.createTestArmTemplate()
+      };
+      await service.deployTemplate(deployment);
+      expect(Deployments.prototype.createOrUpdate).toBeCalled()
+    });
+
+    it("Calls deploy if running first deployment", async () => {
+      ResourceService.prototype.getDeployments = jest.fn(() => {
+        return []
+      }) as any;
+      const deployment: ArmDeployment = {
+        parameters: MockFactory.createTestParameters(false),
+        template: MockFactory.createTestArmTemplate()
+      };
+      await service.deployTemplate(deployment);
+      expect(Deployments.prototype.createOrUpdate).toBeCalled()
+    });
+
     it("Appends environment variables into app settings of ARM template", async () => {
       const environmentConfig: any = {
         PARAM_1: "1",