Merge pull request #644 from drashland/feat/resource-loader

feat: add resource loader service (takes in paths and loads resources from it)

src/http/resource.ts

@@ -9,6 +9,11 @@ import * as Drash from "../../mod.ts";
  *     https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Identifying_resources_on_the_Web
  */
 export class Resource implements Drash.Interfaces.IResource {
+  /**
+   * Internal property used to identify this as a Drash resource.
+   */
+  protected drash_resource = true;
+
   public services: Drash.Interfaces.IResourceServices = {};
   public paths: string[] = [];
 

src/http/server.ts

@@ -172,15 +172,15 @@ export class Server {
   }
 
   //////////////////////////////////////////////////////////////////////////////
-  // FILE MARKER - METHODS - PRIVATE /////////////////////////////////////////////
+  // FILE MARKER - METHODS - PRIVATE ///////////////////////////////////////////
   //////////////////////////////////////////////////////////////////////////////
 
   /**
    * Add all resources to this server -- instantiating them so that they
    * are ready to handle requests at runtime.
    */
   #addResources(): void {
-    this.#options.resources.forEach((resourceClass: typeof Drash.Resource) => {
+    this.#options.resources?.forEach((resourceClass: typeof Drash.Resource) => {
       this.addResource(resourceClass);
     });
   }

src/interfaces.ts

@@ -147,7 +147,7 @@ export interface IServerOptions {
   key_file?: string;
   port: number;
   protocol: "http" | "https";
-  resources: typeof Resource[];
+  resources?: typeof Resource[];
   services?: IService[];
   // deno-lint-ignore no-explicit-any camelcase
   error_handler?: new (...args: any[]) => IErrorHandler;

src/services/resource_loader/deps.ts

@@ -0,0 +1,2 @@
+export { walkSync } from "https://deno.land/std@0.146.0/fs/mod.ts";
+export { join } from "https://deno.land/std@0.146.0/path/mod.ts";

src/services/resource_loader/resource_loader.ts

@@ -0,0 +1,122 @@
+import { Interfaces, Resource, Service } from "../../../mod.ts";
+import { join, walkSync } from "./deps.ts";
+
+interface IOptions {
+  /**
+   * The paths to the resources.
+   *
+   * @example
+   * ```typescript
+   * ["./resources/api", "./resources/ssr"]
+   * ```
+   */
+  paths_to_resources: string[];
+}
+
+export class ResourceLoaderService extends Service {
+  #options: IOptions;
+
+  /**
+   * Autoload resources in the provided `options.paths_to_resources` option.
+   * @param options - See `IOptions`. More information can be found at https://drash.land/drash.
+   *
+   * @example
+   * ```typescript
+   * const resourceLoader = new ResourceLoaderService({
+   *   paths_to_resources: [
+   *     "./resources/api", // Loads all resources in ./resources/api directory
+   *     "./resources/ssr", // Loads all resources in ./resources/ssr directory
+   *   ],
+   * });
+   *
+   * const server = new Drash.Server({
+   *   protocol: "http",
+   *   hostname: "localhost",
+   *   port: 1337,
+   *   services: [
+   *     resourceLoader, // Plug in the service to add the autoloaded resources
+   *   ],
+   * });
+   * ```
+   */
+  constructor(options: IOptions) {
+    super();
+    this.#options = options;
+  }
+
+  public async runAtStartup(
+    options: Interfaces.IServiceStartupOptions,
+  ): Promise<void> {
+    for (const basePath of this.#options.paths_to_resources) {
+      for (const entry of walkSync(basePath)) {
+        if (!entry.isFile) {
+          continue;
+        }
+
+        const fileAsModule = await import(
+          this.#getUrlWithFileScheme(entry.path)
+        );
+
+        if (!fileAsModule || typeof fileAsModule !== "object") {
+          continue;
+        }
+
+        const exportedMemberNames = Object.keys(fileAsModule);
+
+        if (!exportedMemberNames || exportedMemberNames.length <= 0) {
+          continue;
+        }
+
+        for (const exportedMemberName of exportedMemberNames) {
+          const exportedMember = (fileAsModule as { [k: string]: unknown })[
+            exportedMemberName as string
+          ];
+
+          if (typeof exportedMember !== "function") {
+            continue;
+          }
+
+          const typeSafeExportedMember =
+            exportedMember as unknown as typeof Resource;
+
+          try {
+            const obj = new typeSafeExportedMember();
+            const propertyNames = Object.getOwnPropertyNames(obj);
+            if (!propertyNames.includes("drash_resource")) {
+              continue;
+            }
+
+            options.server.addResource(typeSafeExportedMember);
+          } catch (_error) {
+            // If `obj` cannot be instantiated, then skip it
+          }
+        }
+      }
+    }
+  }
+
+  /**
+   * In some cases, the file:// scheme may be missing. To make sure it is always
+   * present when using dynamic imports, we check if it's missing and add it if
+   * so.
+   *
+   * @param path - The path that may have a missing file:// scheme.
+   *
+   * @returns The path if file:// exists or a new path with file:// added.
+   */
+  #getUrlWithFileScheme(path: string): string {
+    const scheme = "file://";
+
+    const url = new URL(join(Deno.cwd(), path), scheme + Deno.cwd());
+
+    let urlWithFileScheme = url.href;
+
+    // If the file:// scheme is not included during URL creation, then make sure
+    // it is added
+    if (!urlWithFileScheme.includes(scheme)) {
+      urlWithFileScheme = scheme + urlWithFileScheme;
+    }
+
+    return urlWithFileScheme;
+  }
+}

tests/integration/services/resource_loader/resource_loader_test.ts

@@ -0,0 +1,82 @@
+import { assertEquals, Drash } from "../../../deps.ts";
+import { ResourceLoaderService } from "../../../../src/services/resource_loader/resource_loader.ts";
+
+/**
+ * Helper function to start the server in a test that can close it to prevent
+ * leaking async ops. The server needs to start and stop in the same test.
+ * @returns The server so it can be closed in the test.
+ */
+async function startServer(port: number) {
+  const resourceLoader = new ResourceLoaderService({
+    paths_to_resources: [
+      "./tests/integration/services/resource_loader/resources/api",
+      "./tests/integration/services/resource_loader/resources/ssr",
+    ],
+  });
+
+  const server = new Drash.Server({
+    protocol: "http",
+    hostname: "localhost",
+    port: port,
+    services: [
+      resourceLoader,
+    ],
+  });
+
+  await server.run();
+
+  return server;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// FILE MARKER - TESTS /////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+
+Deno.test("resource_loader_test.ts", async (t) => {
+  await t.step("GET /home", async (t) => {
+    await t.step("should return the homepage", async () => {
+      const server = await startServer(3000);
+      const res = await fetch(`${server.address}/home`);
+      await server.close();
+      const actual = await res.text();
+      assertEquals(res.headers.get("content-type"), "text/html");
+      assertEquals(actual, "<div>Homepage</div>");
+    });
+  });
+
+  await t.step("GET /api/users", async (t) => {
+    await t.step("should return a users array", async () => {
+      const server = await startServer(3001);
+
+      const resGet = await fetch(`${server.address}/api/users`);
+      assertEquals(resGet.headers.get("content-type"), "application/json");
+      assertEquals(await resGet.json(), [
+        {
+          id: 1,
+          name: "Ed",
+        },
+        {
+          id: 2,
+          name: "Breno",
+        },
+      ]);
+
+      const resPost = await fetch(`${server.address}/api/users`, {
+        method: "POST",
+      });
+      assertEquals(resPost.headers.get("content-type"), "application/json");
+      assertEquals(await resPost.json(), [
+        {
+          id: 1,
+          name: "Eric",
+        },
+        {
+          id: 2,
+          name: "Sara",
+        },
+      ]);
+
+      await server.close();
+    });
+  });
+});

tests/integration/services/resource_loader/resources/api/users_resource.ts

@@ -0,0 +1,31 @@
+import { Drash } from "../../../../../deps.ts";
+
+export class UsersResource extends Drash.Resource {
+  paths = ["/api/users"];
+
+  public GET(_request: Drash.Request, response: Drash.Response) {
+    response.json([
+      {
+        id: 1,
+        name: "Ed",
+      },
+      {
+        id: 2,
+        name: "Breno",
+      },
+    ]);
+  }
+
+  public POST(_request: Drash.Request, response: Drash.Response) {
+    response.json([
+      {
+        id: 1,
+        name: "Eric",
+      },
+      {
+        id: 2,
+        name: "Sara",
+      },
+    ]);
+  }
+}

tests/integration/services/resource_loader/resources/ssr/home_resource.ts

@@ -0,0 +1,9 @@
+import { Drash } from "../../../../../deps.ts";
+
+export class HomeResource extends Drash.Resource {
+  paths = ["/home"];
+
+  public GET(_request: Drash.Request, response: Drash.Response) {
+    response.html("<div>Homepage</div>");
+  }
+}