feat: implement no-content verification strategy

package.json

@@ -61,6 +61,7 @@
     "@resvg/resvg-js": "^2.4.1",
     "class-transformer": "^0.5.1",
     "class-validator": "^0.14.0",
+    "fastify": "^4.15.0",
     "nestjs-pino": "^3.1.2",
     "octokit": "^2.0.14",
     "pino-http": "^8.3.3",
@@ -81,13 +82,12 @@
     "@open-sauced/conventional-commit": "^1.0.1",
     "@swc/core": "^1.3.32",
     "@types/eslint": "^8.21.0",
-    "@types/express": "^4.17.17",
     "@types/jest": "29.5.0",
     "@types/node": "18.15.11",
     "@types/rimraf": "^3.0.2",
     "@types/semver": "^7.3.13",
+    "@types/source-map-support": "^0.5.6",
     "@types/supertest": "^2.0.12",
-    "@types/validator": "^13.7.11",
     "@typescript-eslint/eslint-plugin": "^5.57.0",
     "@typescript-eslint/parser": "^5.57.0",
     "eslint": "^8.37.0",

src/s3-file-storage/s3-file-storage.service.ts

@@ -61,8 +61,6 @@ export class S3FileStorageService {
 
       return response.LastModified ?? null;
     } catch (error) {
-      console.error(error);
-
       if (error instanceof Error) {
         if (error.name === "NotFound") {
           return null;
@@ -77,6 +75,7 @@ export class S3FileStorageService {
     fileContent: Buffer | Readable,
     hash: string,
     contentType: string,
+    metadata?: Record<string, string>,
   ): Promise<void> {
     await this.s3Client.send(
       new PutObjectCommand({
@@ -85,6 +84,7 @@ export class S3FileStorageService {
         Body: fileContent,
         ContentType: contentType,
         ACL: "public-read",
+        Metadata: metadata,
       }),
     );
   }

src/social-card/social-card.controller.ts

@@ -1,5 +1,12 @@
-import { Controller, Get, Header, Param, Redirect, StreamableFile } from "@nestjs/common";
-import { ApiNotFoundResponse, ApiOkResponse, ApiOperation, ApiTags } from "@nestjs/swagger";
+import { Controller, Get, Head, Header, HttpStatus, Param, Redirect, Res, StreamableFile } from "@nestjs/common";
+import {
+  ApiNoContentResponse,
+  ApiNotFoundResponse,
+  ApiOkResponse,
+  ApiOperation, ApiResponse,
+  ApiTags,
+} from "@nestjs/swagger";
+import { FastifyReply } from "fastify";
 
 import { SocialCardService } from "./social-card.service";
 
@@ -10,20 +17,40 @@ export class SocialCardController {
     private readonly socialCardService: SocialCardService,
   ) {}
 
+  @Head("/:username")
+  @ApiNoContentResponse({ description: "User social card image is up to date", status: HttpStatus.NO_CONTENT })
+  @ApiResponse({ description: "User social card image needs regeneration", status: HttpStatus.NOT_MODIFIED })
+  @ApiNotFoundResponse({ description: "User social card image not found", status: HttpStatus.NOT_FOUND })
+  async checkUserSocialCard (
+    @Param("username") username: string,
+      @Res() res: FastifyReply,
+  ): Promise<void> {
+    const { fileUrl, hasFile, needsUpdate, lastModified } = await this.socialCardService.checkRequiresUpdate(username);
+
+    return res
+      .headers({
+        "x-amz-meta-last-modified": lastModified?.toISOString() ?? "",
+        "x-amz-meta-location": fileUrl,
+      })
+      .status(hasFile ? needsUpdate ? HttpStatus.NOT_MODIFIED : HttpStatus.NO_CONTENT : HttpStatus.NOT_FOUND)
+      .send();
+  }
+
   @Get("/:username")
   @ApiOperation({
     operationId: "generateUserSocialCard",
     summary: "Gets latest cache aware social card link for :username or generates a new one",
   })
   @Header("Content-Type", "image/png")
-  @ApiOkResponse({ type: StreamableFile })
+  @ApiOkResponse({ type: StreamableFile, description: "Social card image" })
   @ApiNotFoundResponse({ description: "User not found" })
   @Redirect()
   async generateUserSocialCard (
     @Param("username") username: string,
-  ): Promise<{ url: string }> {
+      @Res() res: FastifyReply,
+  ): Promise<void> {
     const url = await this.socialCardService.getUserCard(username);
 
-    return { url };
+    return res.status(302).redirect(url);
   }
 }

src/social-card/social-card.service.ts

@@ -11,6 +11,13 @@ import { GithubService } from "../github/github.service";
 import { S3FileStorageService } from "../s3-file-storage/s3-file-storage.service";
 import tailwindConfig from "./templates/tailwind.config";
 
+interface RequiresUpdateMeta {
+  fileUrl: string,
+  hasFile: boolean;
+  needsUpdate: boolean;
+  lastModified: Date | null,
+}
+
 @Injectable()
 export class SocialCardService {
   private readonly logger = new Logger(this.constructor.name);
@@ -67,6 +74,32 @@ export class SocialCardService {
     };
   }
 
+  async checkRequiresUpdate (username: string): Promise<RequiresUpdateMeta> {
+    const hash = `users/${String(username)}.png`;
+    const fileUrl = `${this.s3FileStorageService.getCdnEndpoint()}${hash}`;
+    const hasFile = await this.s3FileStorageService.fileExists(hash);
+    const today3daysAgo = new Date((new Date).setDate((new Date).getDate() - 0.001));
+    const returnVal: RequiresUpdateMeta = {
+      fileUrl,
+      hasFile,
+      needsUpdate: true,
+      lastModified: null,
+    };
+
+    if (hasFile) {
+      const lastModified = await this.s3FileStorageService.getFileLastModified(hash);
+
+      returnVal.lastModified = lastModified;
+
+      if (lastModified && lastModified > today3daysAgo) {
+        this.logger.debug(`User ${username} exists in S3 with lastModified: ${lastModified.toISOString()} less than 3 days ago, redirecting to ${fileUrl}`);
+        returnVal.needsUpdate = true;
+      }
+    }
+
+    return returnVal;
+  }
+
   async getUserCard (username: string): Promise<string> {
     const { remaining } = await this.githubService.rateLimit();
 
@@ -81,15 +114,14 @@ export class SocialCardService {
     const hash = `users/${String(id)}.png`;
     const fileUrl = `${this.s3FileStorageService.getCdnEndpoint()}${hash}`;
     const hasFile = await this.s3FileStorageService.fileExists(hash);
-    const today = (new Date);
-    const today3daysAgo = new Date((new Date).setDate(today.getDate() - 3));
+    const today3daysAgo = new Date((new Date).setDate((new Date).getDate() - 0.001));
 
     if (hasFile) {
       // route to s3
       const lastModified = await this.s3FileStorageService.getFileLastModified(hash);
 
       if (lastModified && lastModified > today3daysAgo) {
-        this.logger.debug(`User ${username} exists in S3 with lastModified: ${lastModified.toISOString()} higher than 3 days ago, redirecting`);
+        this.logger.debug(`User ${username} exists in S3 with lastModified: ${lastModified.toISOString()} less than 3 days ago, redirecting`);
         return fileUrl;
       }
     }
@@ -118,7 +150,7 @@ export class SocialCardService {
 
     const pngBuffer = pngData.asPng();
 
-    await this.s3FileStorageService.uploadFile(pngBuffer, hash, "image/png");
+    await this.s3FileStorageService.uploadFile(pngBuffer, hash, "image/png", { "x-amz-meta-user-id": String(id) });
 
     this.logger.debug(`User ${username} did not exist in S3, generated image and uploaded to S3, redirecting`);