feat: DevContainer component (projen#391)

Fixes projen#362 

BREAKING CHANGES:
- Deprecated `GitpodDocker` for `DevEnvironmentDockerImage`.
- Renamed `gitpod.addCustomDocker()` to `gitpod.addDockerImage`
- Changed `gitpod.addTasks` to take `Task` instances as inputs. Tasks can be created via `const task = project.addTask('name', { ...options })`.

Other changes:

- Creates an abstract interface for configuring container-based developer environments like Gitpod and GitHub Codespaces.
- Adds `addTaskWithOptions`, `addPorts`, `addPrebuilds`, and `addVscodeExtensions` methods to `Gitpod`.
- Adds the `DevContainer` component which emits `.devcontainer.json` files.
- Fix bug where `YAMLFile` can synthesize incorrectly because `JsonFileOptions` get ignored.
- Refactored several unit tests

Author: Chriscbr

.devcontainer.json

@@ -0,0 +1,3 @@
+{
+  "postCreateCommand": "( npx projen devenv:setup )"
+}

.gitignore

@@ -46,6 +46,7 @@ tsconfig.json
 !/.projen/tasks.json
 !/.projen/deps.json
 !/.gitpod.yml
+!/.devcontainer.json
 !/package.json
 !/LICENSE
 !/.npmignore

.gitpod.yml

@@ -2,6 +2,6 @@
 
 tasks:
   - name: Setup
+    command: npx projen build
     init: yarn install
     prebuild: bash ./projen.bash
-    command: npx projen build

.projen/tasks.json

@@ -212,6 +212,17 @@
           "exec": "rm README.md.bak"
         }
       ]
+    },
+    "devenv:setup": {
+      "name": "devenv:setup",
+      "steps": [
+        {
+          "exec": "yarn install"
+        },
+        {
+          "spawn": "build"
+        }
+      ]
     }
   },
   "env": {

.projenrc.js

@@ -35,6 +35,7 @@ const project = new JsiiProject({
   codeCov: true,
   compileBeforeTest: true, // since we want to run the cli in tests
   gitpod: true,
+  devContainer: true,
   // since this is projen, we need to always compile before we run
   projenCommand: '/bin/bash ./projen.bash',
 });
@@ -100,11 +101,16 @@ project.github.addMergifyRules({
   ],
 });
 
-project.gitpod.addTasks({
+project.gitpod.addCustomTask({
   name: 'Setup',
   init: 'yarn install',
   prebuild: 'bash ./projen.bash',
   command: 'npx projen build',
 });
 
+const setup = project.addTask('devenv:setup');
+setup.exec('yarn install');
+setup.spawn(project.buildTask);
+project.devContainer.addTasks(setup);
+
 project.synth();

API.md

@@ -26,7 +26,8 @@
     "eslint": "/bin/bash ./projen.bash eslint",
     "compat": "/bin/bash ./projen.bash compat",
     "docgen": "/bin/bash ./projen.bash docgen",
-    "readme-macros": "/bin/bash ./projen.bash readme-macros"
+    "readme-macros": "/bin/bash ./projen.bash readme-macros",
+    "devenv:setup": "/bin/bash ./projen.bash devenv:setup"
   },
   "author": {
     "name": "Elad Ben-Israel",

package.json

@@ -0,0 +1,97 @@
+import { Task } from './tasks';
+
+/**
+ * Base options for configuring a container-based development environemnt.
+ */
+export interface DevEnvironmentOptions {
+  /**
+   * A Docker image or Dockerfile for the container.
+   */
+  readonly dockerImage?: DevEnvironmentDockerImage;
+
+  /**
+   * An array of tasks that should be run when the container starts.
+   */
+  readonly tasks?: Task[];
+
+  /**
+   * An array of ports that should be exposed from the container.
+   */
+  readonly ports?: string[];
+
+  /**
+   * An array of extension IDs that specify the extensions that should be
+   * installed inside the container when it is created.
+   */
+  readonly vscodeExtensions?: string[];
+}
+
+/**
+ * Options for specifying the Docker image of the container.
+ */
+export class DevEnvironmentDockerImage {
+  /**
+   * A publicly available Docker image.
+   * @example 'ubuntu:latest'
+   * @param image a Docker image
+   */
+  public static fromImage(image: string): DevEnvironmentDockerImage {
+    return { image };
+  }
+
+  /**
+   * The relative path of a Dockerfile that defines the container contents.
+   * @example '.gitpod.Docker'
+   * @param dockerFile a relative path
+   */
+  public static fromFile(dockerFile: string): DevEnvironmentDockerImage {
+    return { dockerFile };
+  }
+
+  /**
+   * A publicly available Docker image.
+   */
+  public readonly image?: string;
+
+  /**
+   * The relative path of a Dockerfile that defines the container contents.
+   */
+  public readonly dockerFile?: string;
+
+  private constructor() { }
+}
+
+/**
+ * Abstract interface for container-based development environments, such as
+ * Gitpod and GitHub Codespaces.
+ */
+export interface IDevEnvironment {
+  /**
+   * Add a custom Docker image or Dockerfile for the container.
+   *
+   * @param image The Docker image
+   */
+  addDockerImage(image: DevEnvironmentDockerImage): void;
+
+  /**
+   * Adds tasks to run when the container starts.
+   *
+   * @param tasks The new tasks
+   */
+  addTasks(...tasks: Task[]): void;
+
+  /**
+   * Adds ports that should be exposed (forwarded) from the container.
+   *
+   * @param ports The new ports
+   */
+  addPorts(...ports: string[]): void;
+
+  /**
+   * Adds a list of VSCode extensions that should be automatically installed
+   * in the container.
+   *
+   * @param extensions The extension IDs
+   */
+  addVscodeExtensions(...extensions: string[]): void;
+}