cli: build out task lib a bit with command execution, adding deps

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

packages/cli/src/lib/tasks.ts

@@ -18,9 +18,14 @@ import chalk from 'chalk';
 import fs from 'fs-extra';
 import handlebars from 'handlebars';
 import ora from 'ora';
+import { promisify } from 'util';
 import { basename, dirname } from 'path';
 import recursive from 'recursive-readdir';
+import { exec as execCb } from 'child_process';
 import { paths } from './paths';
+import { assertError } from '@backstage/errors';
+
+const exec = promisify(execCb);
 
 const TASK_NAME_MAX_LENGTH = 14;
 
@@ -42,11 +47,11 @@ export class Task {
     process.exit(code);
   }
 
-  static async forItem(
+  static async forItem<T = void>(
     task: string,
     item: string,
-    taskFunc: () => Promise<void>,
-  ): Promise<void> {
+    taskFunc: () => Promise<T>,
+  ): Promise<T> {
     const paddedTask = chalk.green(task.padEnd(TASK_NAME_MAX_LENGTH));
 
     const spinner = ora({
@@ -56,13 +61,40 @@ export class Task {
     }).start();
 
     try {
-      await taskFunc();
+      const result = await taskFunc();
       spinner.succeed();
+      return result;
     } catch (error) {
       spinner.fail();
       throw error;
     }
   }
+
+  static async forCommand(
+    command: string,
+    options?: { cwd?: string; optional?: boolean },
+  ) {
+    try {
+      await Task.forItem('executing', command, async () => {
+        await exec(command, { cwd: options?.cwd });
+      });
+    } catch (error) {
+      assertError(error);
+      if (error.stderr) {
+        process.stdout.write(error.stderr as Buffer);
+      }
+      if (error.stdout) {
+        process.stdout.write(error.stdout as Buffer);
+      }
+      if (options?.optional) {
+        Task.error(`Warning: Failed to execute command ${chalk.cyan(command)}`);
+      } else {
+        throw new Error(
+          `Failed to execute command '${chalk.cyan(command)}', ${error}`,
+        );
+      }
+    }
+  }
 }
 
 export async function templatingTask(
@@ -122,3 +154,44 @@ export async function templatingTask(
     }
   }
 }
+
+export async function addPackageDependency(
+  path: string,
+  options: {
+    dependencies?: Record<string, string>;
+    devDependencies?: Record<string, string>;
+    peerDependencies?: Record<string, string>;
+  },
+) {
+  try {
+    const pkgJson = await fs.readJson(path);
+
+    const normalize = (obj: Record<string, string>) => {
+      if (Object.keys(obj).length === 0) {
+        return undefined;
+      }
+      return Object.fromEntries(
+        Object.keys(obj)
+          .sort()
+          .map(key => [key, obj[key]]),
+      );
+    };
+
+    pkgJson.dependencies = normalize({
+      ...pkgJson.dependencies,
+      ...options.dependencies,
+    });
+    pkgJson.devDependencies = normalize({
+      ...pkgJson.devDependencies,
+      ...options.devDependencies,
+    });
+    pkgJson.peerDependencies = normalize({
+      ...pkgJson.peerDependencies,
+      ...options.peerDependencies,
+    });
+
+    await fs.writeJson(path, pkgJson, { spaces: 2 });
+  } catch (error) {
+    throw new Error(`Failed to add package dependencies, ${error}`);
+  }
+}