Stories and comments (demo)

Author: koistya

api/schema.graphql

@@ -19,6 +19,8 @@ type Root {
   me: User
   user(username: String!): User
   users(after: String, first: Int): UserConnection
+  story(slug: String!): Story
+  stories: [Story]
 }
 
 # An object with an ID
@@ -114,6 +116,32 @@ type UserEdge {
   cursor: String!
 }
 
+type Story implements Node {
+  # The ID of an object
+  id: ID!
+  author: User!
+  slug: String!
+  title: String!
+  text(truncate: Int): String!
+  isURL: Boolean!
+  comments: [Comment]
+  pointsCount: Int!
+  pointGiven: Boolean!
+  commentsCount: Int!
+  createdAt(format: String): String
+  updatedAt(format: String): String
+}
+
+type Comment implements Node {
+  # The ID of an object
+  id: ID!
+  parent: Comment
+  author: User!
+  text: String
+  createdAt(format: String): String
+  updatedAt(format: String): String
+}
+
 type Mutation {
   # Authenticates user with an ID token or email and password.
   signIn(idToken: String, email: String, password: String): SignInPayload
@@ -123,6 +151,12 @@ type Mutation {
 
   # Updates a user.
   updateUser(input: UpdateUserInput!): UpdateUserPayload
+
+  # Creates or updates a story.
+  upsertStory(input: UpsertStoryInput!): UpsertStoryPayload
+
+  # Marks the story as "liked".
+  likeStory(input: LikeStoryInput!): LikeStoryPayload
 }
 
 type SignInPayload {
@@ -146,3 +180,28 @@ input UpdateUserInput {
   validateOnly: Boolean
   clientMutationId: String
 }
+
+type UpsertStoryPayload {
+  story: Story
+  errors: [[String!]!]
+  clientMutationId: String
+}
+
+input UpsertStoryInput {
+  id: ID
+  title: String
+  text: String
+  approved: Boolean
+  validateOnly: Boolean
+  clientMutationId: String
+}
+
+type LikeStoryPayload {
+  story: Story
+  clientMutationId: String
+}
+
+input LikeStoryInput {
+  id: ID!
+  clientMutationId: String
+}

api/src/context.ts

@@ -7,8 +7,8 @@
 import DataLoader from "dataloader";
 import { Request } from "express";
 
-import db, { User, Identity } from "./db";
-import { mapTo, mapToMany } from "./utils";
+import db, { User, Identity, Story, Comment } from "./db";
+import { mapTo, mapToMany, mapToValues } from "./utils";
 import { UnauthorizedError, ForbiddenError } from "./error";
 
 export class Context {
@@ -89,4 +89,107 @@ export class Context {
       .select()
       .then((rows) => mapToMany(rows, keys, (x) => x.user_id)),
   );
+
+  storyById = new DataLoader<string, Story | null>((keys) =>
+    db
+      .table<Story>("stories")
+      .whereIn("id", keys)
+      .select()
+      .then((rows) => {
+        rows.forEach((x) => this.storyBySlug.prime(x.slug, x));
+        return rows;
+      })
+      .then((rows) => mapTo(rows, keys, (x) => x.id)),
+  );
+
+  storyBySlug = new DataLoader<string, Story | null>((keys) =>
+    db
+      .table<Story>("stories")
+      .whereIn("slug", keys)
+      .select()
+      .then((rows) => {
+        rows.forEach((x) => this.storyById.prime(x.id, x));
+        return rows;
+      })
+      .then((rows) => mapTo(rows, keys, (x) => x.slug)),
+  );
+
+  storyCommentsCount = new DataLoader<string, number>((keys) =>
+    db
+      .table<Comment>("comments")
+      .whereIn("story_id", keys)
+      .groupBy("story_id")
+      .select<{ story_id: string; count: string }[]>(
+        "story_id",
+        db.raw("count(story_id)"),
+      )
+      .then((rows) =>
+        mapToValues(
+          rows,
+          keys,
+          (x) => x.story_id,
+          (x) => (x ? Number(x.count) : 0),
+        ),
+      ),
+  );
+
+  storyPointsCount = new DataLoader<string, number>((keys) =>
+    db
+      .table("stories")
+      .leftJoin("story_points", "story_points.story_id", "stories.id")
+      .whereIn("stories.id", keys)
+      .groupBy("stories.id")
+      .select("stories.id", db.raw("count(story_points.user_id)::int"))
+      .then((rows) =>
+        mapToValues(
+          rows,
+          keys,
+          (x) => x.id,
+          (x) => (x ? parseInt(x.count, 10) : 0),
+        ),
+      ),
+  );
+
+  storyPointGiven = new DataLoader<string, boolean>((keys) => {
+    const currentUser = this.user;
+    const userId = currentUser ? currentUser.id : "";
+
+    return db
+      .table("stories")
+      .leftJoin("story_points", function join() {
+        this.on("story_points.story_id", "stories.id").andOn(
+          "story_points.user_id",
+          db.raw("?", [userId]),
+        );
+      })
+      .whereIn("stories.id", keys)
+      .select<{ id: string; given: boolean }[]>(
+        "stories.id",
+        db.raw("(story_points.user_id IS NOT NULL) AS given"),
+      )
+      .then((rows) =>
+        mapToValues(
+          rows,
+          keys,
+          (x) => x.id,
+          (x) => x?.given || false,
+        ),
+      );
+  });
+
+  commentById = new DataLoader<string, Comment | null>((keys) =>
+    db
+      .table<Comment>("comments")
+      .whereIn("id", keys)
+      .select()
+      .then((rows) => mapTo(rows, keys, (x) => x.id)),
+  );
+
+  commentsByStoryId = new DataLoader<string, Comment[]>((keys) =>
+    db
+      .table<Comment>("comments")
+      .whereIn("story_id", keys)
+      .select()
+      .then((rows) => mapToMany(rows, keys, (x) => x.story_id)),
+  );
 }

api/src/db.ts

@@ -49,6 +49,21 @@ export enum IdentityProvider {
   playgames = "playgames",
 }
 
+export type CommentPoint = {
+  comment_id: string;
+  user_id: string;
+};
+
+export type Comment = {
+  id: string;
+  story_id: string;
+  parent_id: string | null;
+  author_id: string;
+  text: string | null;
+  created_at: Date;
+  updated_at: Date;
+};
+
 export type Identity = {
   provider: IdentityProvider;
   id: string;
@@ -71,6 +86,23 @@ export type Identity = {
   expires_at: Date | null;
 };
 
+export type Story = {
+  id: string;
+  author_id: string;
+  slug: string;
+  title: string;
+  text: string | null;
+  is_url: boolean;
+  approved: boolean;
+  created_at: Date;
+  updated_at: Date;
+};
+
+export type StoryPoint = {
+  story_id: string;
+  user_id: string;
+};
+
 export type User = {
   id: string;
   username: string;

api/src/mutations/index.ts

@@ -6,3 +6,4 @@
 
 export * from "./auth";
 export * from "./user";
+export * from "./story";