User stories and comments (demo)

api/context.ts

@@ -6,10 +6,10 @@
 
 import DataLoader from "dataloader";
 import { Request } from "express";
-import type { User, Identity } from "db";
+import type { User, Identity, Story, Comment } from "db";
 
 import db from "./db";
-import { mapTo, mapToMany } from "./utils";
+import { mapTo, mapToMany, mapToValues } from "./utils";
 import { UnauthorizedError, ForbiddenError } from "./error";
 
 export class Context {
@@ -90,4 +90,107 @@ 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/mutations/index.ts

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

api/mutations/story.ts

@@ -0,0 +1,160 @@
+/**
+ * GraphQL API mutations related to stories.
+ *
+ * @copyright 2016-present Kriasoft (https://git.io/vMINh)
+ */
+
+import slugify from "slugify";
+import validator from "validator";
+import { v4 as uuid } from "uuid";
+import { mutationWithClientMutationId } from "graphql-relay";
+import {
+  GraphQLNonNull,
+  GraphQLID,
+  GraphQLString,
+  GraphQLBoolean,
+  GraphQLList,
+} from "graphql";
+
+import db, { Story } from "../db";
+import { Context } from "../context";
+import { StoryType } from "../types";
+import { fromGlobalId, validate } from "../utils";
+
+function slug(text: string) {
+  return slugify(text, { lower: true });
+}
+
+export const upsertStory = mutationWithClientMutationId({
+  name: "UpsertStory",
+  description: "Creates or updates a story.",
+
+  inputFields: {
+    id: { type: GraphQLID },
+    title: { type: GraphQLString },
+    text: { type: GraphQLString },
+    approved: { type: GraphQLBoolean },
+    validateOnly: { type: GraphQLBoolean },
+  },
+
+  outputFields: {
+    story: { type: StoryType },
+    errors: {
+      // TODO: Extract into a custom type.
+      type: new GraphQLList(
+        new GraphQLNonNull(new GraphQLList(new GraphQLNonNull(GraphQLString))),
+      ),
+    },
+  },
+
+  async mutateAndGetPayload(input, ctx: Context) {
+    const id = input.id ? fromGlobalId(input.id, "Story") : null;
+    const newId = uuid();
+
+    let story: Story | undefined;
+
+    if (id) {
+      story = await db.table<Story>("stories").where({ id }).first();
+
+      if (!story) {
+        throw new Error(`Cannot find the story # ${id}.`);
+      }
+
+      // Only the author of the story or admins can edit it
+      ctx.ensureAuthorized(
+        (user) => story?.author_id === user.id || user.admin,
+      );
+    } else {
+      ctx.ensureAuthorized();
+    }
+
+    // Validate and sanitize user input
+    const { data, errors } = validate(input, (x) =>
+      x
+        .field("title", { trim: true })
+        .isRequired()
+        .isLength({ min: 5, max: 80 })
+
+        .field("text", { alias: "URL or text", trim: true })
+        .isRequired()
+        .isLength({ min: 10, max: 1000 })
+
+        .field("text", {
+          trim: true,
+          as: "is_url",
+          transform: (x) =>
+            validator.isURL(x, { protocols: ["http", "https"] }),
+        })
+
+        .field("approved")
+        .is(() => Boolean(ctx.user?.admin), "Only admins can approve a story."),
+    );
+
+    if (errors.length > 0) {
+      return { errors };
+    }
+
+    if (data.title) {
+      data.slug = `${slug(data.title)}-${(id || newId).substr(29)}`;
+    }
+
+    if (id && Object.keys(data).length) {
+      [story] = await db
+        .table<Story>("stories")
+        .where({ id })
+        .update({
+          ...(data as Partial<Story>),
+          updated_at: db.fn.now(),
+        })
+        .returning("*");
+    } else {
+      [story] = await db
+        .table<Story>("stories")
+        .insert({
+          id: newId,
+          ...(data as Partial<Story>),
+          author_id: ctx.user?.id,
+          approved: ctx.user?.admin ? true : false,
+        })
+        .returning("*");
+    }
+
+    return { story };
+  },
+});
+
+export const likeStory = mutationWithClientMutationId({
+  name: "LikeStory",
+  description: 'Marks the story as "liked".',
+
+  inputFields: {
+    id: { type: new GraphQLNonNull(GraphQLID) },
+  },
+
+  outputFields: {
+    story: { type: StoryType },
+  },
+
+  async mutateAndGetPayload(input, ctx: Context) {
+    // Check permissions
+    ctx.ensureAuthorized();
+
+    const id = fromGlobalId(input.id, "Story");
+    const keys = { story_id: id, user_id: ctx.user.id };
+
+    const points = await db
+      .table("story_points")
+      .where(keys)
+      .select(db.raw("1"));
+
+    if (points.length) {
+      await db.table("story_points").where(keys).del();
+    } else {
+      await db.table("story_points").insert(keys);
+    }
+
+    const story = db.table("stories").where({ id }).first();
+
+    return { story };
+  },
+});

api/node.ts

@@ -17,6 +17,10 @@ export const { nodeInterface, nodeField, nodesField } = nodeDefinitions(
     switch (type) {
       case "User":
         return context.userById.load(id).then(assignType("User"));
+      case "Story":
+        return context.storyById.load(id).then(assignType("Story"));
+      case "Comment":
+        return context.commentById.load(id).then(assignType("Comment"));
       default:
         return null;
     }
@@ -25,6 +29,10 @@ export const { nodeInterface, nodeField, nodesField } = nodeDefinitions(
     switch (getType(obj)) {
       case "User":
         return require("./types").UserType;
+      case "Story":
+        return require("./types").StoryType;
+      case "Comment":
+        return require("./types").CommentType;
       default:
         return null;
     }

api/queries/index.ts

@@ -5,3 +5,4 @@
  */
 
 export * from "./user";
+export * from "./story";

api/queries/story.ts

@@ -0,0 +1,55 @@
+/**
+ * The top-level GraphQL API query fields related to stories.
+ *
+ * @copyright 2016-present Kriasoft (https://git.io/vMINh)
+ */
+
+import {
+  GraphQLList,
+  GraphQLNonNull,
+  GraphQLString,
+  GraphQLFieldConfig,
+} from "graphql";
+
+import db from "../db";
+import { Context } from "../context";
+import { StoryType } from "../types";
+
+export const story: GraphQLFieldConfig<unknown, Context> = {
+  type: StoryType,
+
+  args: {
+    slug: { type: new GraphQLNonNull(GraphQLString) },
+  },
+
+  async resolve(root, { slug }) {
+    let story = await db.table("stories").where({ slug }).first();
+
+    // Attempts to find a story by partial ID contained in the slug.
+    if (!story) {
+      const match = slug.match(/[a-f0-9]{7}$/);
+      if (match) {
+        story = await db
+          .table("stories")
+          .whereRaw(`id::text LIKE '%${match[0]}'`)
+          .first();
+      }
+    }
+
+    return story;
+  },
+};
+
+export const stories: GraphQLFieldConfig<unknown, Context> = {
+  type: new GraphQLList(StoryType),
+
+  resolve(self, args, ctx) {
+    return db
+      .table("stories")
+      .where({ approved: true })
+      .orWhere({ approved: false, author_id: ctx.user ? ctx.user.id : null })
+      .orderBy("created_at", "desc")
+      .limit(100)
+      .select();
+  },
+};