write a snapshot test on new and migrate

guardian · Jan 22, 2021 · 4ad7c58 · 4ad7c58
1 parent 5c89afa
commit 4ad7c58
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Showing 8 changed files with 213 additions and 7 deletions.
diff --git a/src/commands/migrate.test.ts b/src/commands/migrate.test.ts
@@ -37,6 +37,7 @@ describe("The MigrateCommand class", () => {
         cfnFile: "template.ts",
         appPath: `/path/to/output/bin/app.ts`,
         stackPath: `/path/to/output/lib/stack-name.ts`,
+        testPath: `/path/to/output/lib/stack-name.test.ts`,
       });
     });
 
@@ -47,6 +48,7 @@ describe("The MigrateCommand class", () => {
         cfnFile: "template.ts",
         appPath: `/path/to/output/bin/app.ts`,
         stackPath: `/path/to/output/lib/app/stack-name.ts`,
+        testPath: `/path/to/output/lib/app/stack-name.test.ts`,
       });
     });
 

diff --git a/src/commands/migrate.ts b/src/commands/migrate.ts
@@ -8,8 +8,9 @@ import {
   getStackNameFromFileName,
 } from "../utils/args";
 import { parse } from "../utils/cfn";
-import { newAppImports } from "../utils/imports";
+import { newAppImports, newTestImports } from "../utils/imports";
 import { constructStack } from "../utils/stack";
+import { constructTest } from "../utils/snapshot";
 
 interface MigrateCommandConfig {
   cfnPath: string;
@@ -20,6 +21,7 @@ interface MigrateCommandConfig {
   appName: string;
   stackPath: string;
   stackName: string;
+  testPath: string;
 }
 
 interface MigrateCommandArgs {
@@ -91,6 +93,9 @@ export class MigrateCommand extends Command {
       stackPath: `${cdkDir}/lib/${
         flags["multi-app"] ? `${kebabAppName}/` : ""
       }${kebabStackName}.ts`,
+      testPath: `${cdkDir}/lib/${
+        flags["multi-app"] ? `${kebabAppName}/` : ""
+      }${kebabStackName}.test.ts`,
     };
 
     MigrateCommand.validateConfig(config);
@@ -140,5 +145,16 @@ export class MigrateCommand extends Command {
         config.stackPath
       )} using @guardian/cdk-cli\n// It is a starting point for migration to CDK *only*. Please check the output carefully before deploying`,
     });
+
+    await constructTest({
+      stackName: config.stackName,
+      appName: config.appName,
+      outputFile: basename(config.testPath),
+      outputDir: dirname(config.stackPath),
+      imports: newTestImports(config.stackName),
+      comment: `// This file was autogenerated from ${basename(
+        config.stackPath
+      )} using @guardian/cdk-cli\n// It is a starting point for migration to CDK *only*. Please check the output carefully before deploying`,
+    });
   }
 }
diff --git a/src/commands/new.test.ts b/src/commands/new.test.ts
@@ -34,6 +34,7 @@ describe("The NewCommand class", () => {
       expect(NewCommand.getConfig(args)).toMatchObject({
         appPath: `/path/to/output/bin/app.ts`,
         stackPath: `/path/to/output/lib/stack-name.ts`,
+        testPath: `/path/to/output/lib/stack-name.test.ts`,
       });
     });
 
@@ -43,6 +44,7 @@ describe("The NewCommand class", () => {
       ).toMatchObject({
         appPath: `/path/to/output/bin/app.ts`,
         stackPath: `/path/to/output/lib/app/stack-name.ts`,
+        testPath: `/path/to/output/lib/app/stack-name.test.ts`,
       });
     });
   });

diff --git a/src/commands/new.ts b/src/commands/new.ts
@@ -7,10 +7,15 @@ import { Command, flags } from "@oclif/command";
 import kebabCase from "lodash.kebabcase";
 import { constructApp } from "../utils/app";
 import { checkPathDoesNotExist, checkPathExists } from "../utils/args";
-import { newAppImports, newStackImports } from "../utils/imports";
+import {
+  newAppImports,
+  newStackImports,
+  newTestImports,
+} from "../utils/imports";
 import { cancellablePrompts } from "../utils/prompts";
 import type { StackTemplate } from "../utils/stack";
 import { constructStack } from "../utils/stack";
+import { constructTest } from "../utils/snapshot";
 
 interface NewCommandConfig {
   cdkDir: string;
@@ -19,6 +24,7 @@ interface NewCommandConfig {
   appName: string;
   stackPath: string;
   stackName: string;
+  testPath: string;
 }
 
 interface NewCommandArgs {
@@ -58,7 +64,7 @@ export class NewCommand extends Command {
     },
   ];
 
-  imports = newStackImports();
+  stackImports = newStackImports();
 
   template: StackTemplate = {
     Parameters: {},
@@ -85,6 +91,9 @@ export class NewCommand extends Command {
       stackPath: `${cdkDir}/lib/${
         flags["multi-app"] ? `${kebabAppName}/` : ""
       }${kebabStackName}.ts`,
+      testPath: `${cdkDir}/lib/${
+        flags["multi-app"] ? `${kebabAppName}/` : ""
+      }${kebabStackName}.test.ts`,
     };
 
     NewCommand.validateConfig(config);
@@ -122,13 +131,22 @@ export class NewCommand extends Command {
     });
 
     await constructStack({
-      imports: this.imports,
+      imports: this.stackImports,
       template: this.template,
       stackName: config.stackName,
       outputFile: basename(config.stackPath),
       outputDir: dirname(config.stackPath),
       comment: "// This file was autogenerated using @guardian/cdk-cli",
     });
+
+    await constructTest({
+      imports: newTestImports(config.stackName),
+      stackName: config.stackName,
+      appName: config.appName,
+      outputFile: basename(config.testPath),
+      outputDir: dirname(config.stackPath),
+      comment: "// This file was autogenerated using @guardian/cdk-cli",
+    });
   }
 
   async getParameters(): Promise<void> {
@@ -159,7 +177,7 @@ export class NewCommand extends Command {
           parameterType: "GuStringParameter",
         };
 
-        this.imports.addImport("@guardian/cdk/lib/constructs/core", [
+        this.stackImports.addImport("@guardian/cdk/lib/constructs/core", [
           "GuStringParameter",
         ]);
       } else {
@@ -168,7 +186,7 @@ export class NewCommand extends Command {
           type,
         };
 
-        this.imports.addImport("@guardian/cdk/lib/constructs/core", [
+        this.stackImports.addImport("@guardian/cdk/lib/constructs/core", [
           "GuParameter",
         ]);
       }

diff --git a/src/utils/imports.test.ts b/src/utils/imports.test.ts
@@ -1,5 +1,10 @@
 import { MockCodeMaker } from "../../test/utils/codemaker";
-import { Imports, newAppImports, newStackImports } from "./imports";
+import {
+  Imports,
+  newAppImports,
+  newStackImports,
+  newTestImports,
+} from "./imports";
 
 describe("The Imports class", () => {
   describe("addImport function", () => {
@@ -288,3 +293,32 @@ describe("The newAppImports function", () => {
     });
   });
 });
+
+describe("The newTestImports function", () => {
+  test("adds the correct initial imports", () => {
+    const imports = newTestImports("stack");
+    expect(imports.imports["@aws-cdk/assert"]).toEqual({
+      types: [],
+      components: ["SynthUtils"],
+    });
+
+    expect(imports.imports["@aws-cdk/core"]).toEqual({
+      types: [],
+      components: ["App"],
+    });
+
+    expect(imports.imports["@aws-cdk/assert/jest"]).toEqual({
+      basic: true,
+      types: [],
+      components: [],
+    });
+  });
+
+  test("adds the correct stack import", () => {
+    const imports = newTestImports("StackName");
+    expect(imports.imports["./stack-name"]).toEqual({
+      types: [],
+      components: ["StackName"],
+    });
+  });
+});
diff --git a/src/utils/imports.ts b/src/utils/imports.ts
@@ -116,3 +116,25 @@ export const newAppImports = (
 
   return imports;
 };
+
+export const newTestImports = (name: string): Imports => {
+  const imports = new Imports({
+    "@aws-cdk/assert/jest": {
+      types: [],
+      components: [],
+      basic: true,
+    },
+    "@aws-cdk/assert": {
+      types: [],
+      components: ["SynthUtils"],
+    },
+    "@aws-cdk/core": {
+      types: [],
+      components: ["App"],
+    },
+  });
+
+  imports.addImport(`./${kebabCase(name)}`, [name]);
+
+  return imports;
+};
diff --git a/src/utils/snapshot.test.ts b/src/utils/snapshot.test.ts
@@ -0,0 +1,47 @@
+import { MockCodeMaker } from "../../test/utils/codemaker";
+import { Imports } from "./imports";
+import { TestBuilder } from "./snapshot";
+
+describe("The TestBuilder class", () => {
+  describe("addTest function", () => {
+    const builder = new TestBuilder({
+      outputDir: "",
+      outputFile: "",
+      stackName: "StackName",
+      appName: "AppName",
+      imports: new Imports(),
+    });
+    const codemaker = new MockCodeMaker();
+    builder.code = codemaker.codemaker;
+
+    beforeEach(() => {
+      codemaker.clear();
+    });
+
+    test("adds a snapshot test", () => {
+      builder.addTest();
+      expect(codemaker._codemaker.openBlock).toHaveBeenNthCalledWith(
+        1,
+        `describe("The StackName stack", () =>`
+      );
+      expect(codemaker._codemaker.openBlock).toHaveBeenNthCalledWith(
+        2,
+        `it("matches the snapshot", () =>`
+      );
+      expect(codemaker._codemaker.line).toHaveBeenNthCalledWith(
+        1,
+        `const app = new App();`
+      );
+      expect(codemaker._codemaker.line).toHaveBeenNthCalledWith(
+        2,
+        `const stack = new StackName(app, "stack-name", { app: "app-name" });`
+      );
+      expect(codemaker._codemaker.line).toHaveBeenNthCalledWith(
+        3,
+        `expect(SynthUtils.toCloudFormation(stack)).toMatchSnapshot();`
+      );
+      expect(codemaker._codemaker.closeBlock).toHaveBeenNthCalledWith(1, `});`);
+      expect(codemaker._codemaker.closeBlock).toHaveBeenNthCalledWith(2, `});`);
+    });
+  });
+});
diff --git a/src/utils/snapshot.ts b/src/utils/snapshot.ts
@@ -0,0 +1,65 @@
+import { CodeMaker } from "codemaker";
+import kebabCase from "lodash.kebabcase";
+import type { Imports } from "./imports";
+
+export interface TestBuilderProps {
+  imports: Imports;
+  appName: string;
+  stackName: string;
+  outputFile: string;
+  outputDir: string;
+  comment?: string;
+}
+
+export class TestBuilder {
+  config: TestBuilderProps;
+  imports: Imports;
+
+  code: CodeMaker;
+
+  constructor(props: TestBuilderProps) {
+    this.config = props;
+    this.imports = props.imports;
+
+    this.code = new CodeMaker({ indentationLevel: 2 });
+    this.code.closeBlockFormatter = (s?: string): string => s ?? "}";
+  }
+
+  async constructCdkFile(): Promise<void> {
+    this.code.openFile(this.config.outputFile);
+    if (this.config.comment) {
+      this.code.line(this.config.comment);
+      this.code.line();
+    }
+
+    this.config.imports.render(this.code);
+
+    this.addTest();
+
+    this.code.closeFile(this.config.outputFile);
+    await this.code.save(this.config.outputDir);
+  }
+
+  addTest(): void {
+    this.code.openBlock(`describe("The ${this.config.stackName} stack", () =>`);
+    this.code.openBlock(`it("matches the snapshot", () =>`);
+
+    this.code.line("const app = new App();");
+    this.code.line(
+      `const stack = new ${this.config.stackName}(app, "${kebabCase(
+        this.config.stackName
+      )}", { app: "${kebabCase(this.config.appName)}" });`
+    );
+    this.code.line(
+      "expect(SynthUtils.toCloudFormation(stack)).toMatchSnapshot();"
+    );
+
+    this.code.closeBlock("});");
+    this.code.closeBlock("});");
+  }
+}
+
+export const constructTest = async (props: TestBuilderProps): Promise<void> => {
+  const builder = new TestBuilder(props);
+  await builder.constructCdkFile();
+};