refactor init logic into its own class

src/commands/init.ts

@@ -1,19 +1,8 @@
-import {
-  copyFileSync,
-  existsSync,
-  lstatSync,
-  mkdirSync,
-  readdirSync,
-} from "fs";
-import { join } from "path";
 import { Command, flags } from "@oclif/command";
-import { checkDirectoryIsEmpty } from "../utils/args";
+import { buildDirectory } from "../utils/init";
+import type { InitConfig } from "../utils/init";
 
-interface InitCommandConfig {
-  outputDir: string;
-}
-
-interface InitCommandArgs {
+export interface InitCommandArgs {
   output: string;
 }
 
@@ -37,67 +26,25 @@ export class InitCommand extends Command {
     },
   ];
 
-  static getConfig = ({
-    args,
-  }: {
-    args: InitCommandArgs;
-  }): InitCommandConfig => {
+  static getConfig = ({ args }: { args: InitCommandArgs }): InitConfig => {
     const config = {
       outputDir: args.output,
     };
 
-    InitCommand.validateConfig(config);
-
     return config;
   };
 
-  static validateConfig = (config: InitCommandConfig): void => {
-    checkDirectoryIsEmpty(config.outputDir);
-  };
-
-  templateDir = `${__dirname}/../template`;
-
   // eslint-disable-next-line @typescript-eslint/require-await -- The Command class requires Promise<any> but we don't do anything async here
   async run(): Promise<void> {
     this.log("Starting CDK generator");
 
     const config = InitCommand.getConfig(this.parse(InitCommand));
 
-    if (!existsSync(config.outputDir)) {
-      this.log(`Creating ${config.outputDir}`);
-      mkdirSync(config.outputDir);
-    }
-
-    this.log("Copying template files");
-    // TODO: Replace any params in files with .template extensions
-    this.copyFiles(this.templateDir, config.outputDir);
+    buildDirectory(config, this);
 
-    this.log("Success!");
-    // TODO: Can we do this here?
-    this.log("Run ./script/setup to get started");
     this.log(
       "To migrate existing stacks into your new directory you can run cdk-cli migrate"
     );
     this.log("To create a new stack run cdk-cli new");
   }
-
-  copyFiles(sourcePath: string, targetPath: string): void {
-    for (const file of readdirSync(sourcePath)) {
-      const path = join(sourcePath, file);
-
-      if (path.endsWith(".ignore")) {
-        continue;
-      } else if (lstatSync(path).isDirectory()) {
-        const nestedTargetPath = join(targetPath, file);
-        if (!existsSync(nestedTargetPath)) {
-          mkdirSync(nestedTargetPath);
-        }
-        this.copyFiles(path, nestedTargetPath);
-      } else if (path.endsWith(".template")) {
-        copyFileSync(path, join(targetPath, file.replace(".template", "")));
-      } else {
-        copyFileSync(path, join(targetPath, file));
-      }
-    }
-  }
 }

src/utils/init.test.ts

@@ -0,0 +1,17 @@
+import { ProjectBuilder } from "./init";
+
+describe("The ProjectBuilder class", () => {
+  describe("validateConfig function", () => {
+    test("throws an error if the directory is not empty", () => {
+      expect(() =>
+        ProjectBuilder.validateConfig({ outputDir: "./src" })
+      ).toThrow();
+    });
+
+    test("does not throw an error if the directory is empty", () => {
+      expect(() =>
+        ProjectBuilder.validateConfig({ outputDir: "./src/empty" })
+      ).not.toThrow();
+    });
+  });
+});

src/utils/init.ts

@@ -0,0 +1,73 @@
+import {
+  copyFileSync,
+  existsSync,
+  lstatSync,
+  mkdirSync,
+  readdirSync,
+} from "fs";
+import { join } from "path";
+import type Command from "@oclif/command";
+import { checkDirectoryIsEmpty } from "../utils/args";
+
+export interface InitConfig {
+  outputDir: string;
+}
+
+// TODO: Add yarn or npm flag
+// TODO: Add project name flag
+export class ProjectBuilder {
+  templateDir = `${__dirname}/../template`;
+  config: InitConfig;
+  command: Command;
+
+  static validateConfig = (config: InitConfig): void => {
+    checkDirectoryIsEmpty(config.outputDir);
+  };
+
+  constructor(config: InitConfig, command: Command) {
+    this.config = config;
+    this.command = command;
+  }
+
+  buildDirectory(): void {
+    ProjectBuilder.validateConfig(this.config);
+
+    if (!existsSync(this.config.outputDir)) {
+      this.command.log(`Creating ${this.config.outputDir}`);
+      mkdirSync(this.config.outputDir);
+    }
+
+    this.command.log("Copying template files");
+    // TODO: Replace any params in files with .template extensions
+    this.copyFiles(this.templateDir, this.config.outputDir);
+
+    this.command.log("Success!");
+    // TODO: Can we do this here?
+    this.command.log("Run ./script/setup to install dependencies");
+  }
+
+  copyFiles(sourcePath: string, targetPath: string): void {
+    for (const file of readdirSync(sourcePath)) {
+      const path = join(sourcePath, file);
+
+      if (path.endsWith(".ignore")) {
+        continue;
+      } else if (lstatSync(path).isDirectory()) {
+        const nestedTargetPath = join(targetPath, file);
+        if (!existsSync(nestedTargetPath)) {
+          mkdirSync(nestedTargetPath);
+        }
+        this.copyFiles(path, nestedTargetPath);
+      } else if (path.endsWith(".template")) {
+        copyFileSync(path, join(targetPath, file.replace(".template", "")));
+      } else {
+        copyFileSync(path, join(targetPath, file));
+      }
+    }
+  }
+}
+
+export const buildDirectory = (config: InitConfig, command: Command): void => {
+  const builder = new ProjectBuilder(config, command);
+  builder.buildDirectory();
+};