Basic error checking

src/lib/collectors.js

@@ -10,7 +10,9 @@ const timelineEntryCache = new TtlCache(constants.resource_cache_time)
 
 function fetchUser(username) {
 	return requestCache.getOrFetch("user/"+username, () => {
-		return request(`https://www.instagram.com/${username}/`).then(res => res.text()).then(text => {
+		return request(`https://www.instagram.com/${username}/`).then(res => {
+			if (res.status === 404) throw constants.symbols.NOT_FOUND
+			else return res.text().then(text => {
 				// require down here or have to deal with require loop. require cache will take care of it anyway.
 				// User -> Timeline -> TimelineImage -> collectors -/> User
 				const User = require("./structures/User")
@@ -19,12 +21,13 @@ function fetchUser(username) {
 				return user
 			})
 		})
+	})
 }
 
 /**
  * @param {string} userID
  * @param {string} after
- * @returns {Promise<import("./types").PagedEdges<import("./types").GraphImage>>}
+ * @returns {Promise<import("./types").PagedEdges<import("./types").TimelineEntryN2>>}
  */
 function fetchTimelinePage(userID, after) {
 	const p = new URLSearchParams()
@@ -36,7 +39,7 @@ function fetchTimelinePage(userID, after) {
 	}))
 	return requestCache.getOrFetchPromise("page/"+after, () => {
 		return request(`https://www.instagram.com/graphql/query/?${p.toString()}`).then(res => res.json()).then(root => {
-			/** @type {import("./types").PagedEdges<import("./types").GraphImage>} */
+			/** @type {import("./types").PagedEdges<import("./types").TimelineEntryN2>} */
 			const timeline = root.data.user.edge_owner_to_timeline_media
 			return timeline
 		})
@@ -86,7 +89,12 @@ function fetchShortcodeData(shortcode) {
 		return request(`https://www.instagram.com/graphql/query/?${p.toString()}`).then(res => res.json()).then(root => {
 			/** @type {import("./types").TimelineEntryN3} */
 			const data = root.data.shortcode_media
+			if (data == null) {
+				// the thing doesn't exist
+				throw constants.symbols.NOT_FOUND
+			} else {
 				return data
+			}
 		})
 	})
 }

src/lib/constants.js

@@ -16,6 +16,8 @@ module.exports = {
 		TYPE_VIDEO: Symbol("TYPE_VIDEO"),
 		TYPE_GALLERY: Symbol("TYPE_GALLERY"),
 		TYPE_GALLERY_IMAGE: Symbol("TYPE_GALLERY_IMAGE"),
-		TYPE_GALLERY_VIDEO: Symbol("TYPE_GALLERY_VIDEO")
+		TYPE_GALLERY_VIDEO: Symbol("TYPE_GALLERY_VIDEO"),
+		NOT_FOUND: Symbol("NOT_FOUND"),
+		NO_SHARED_DATA: Symbol("NO_SHARED_DATA")
 	}
 }

src/lib/structures/TimelineEntry.js

@@ -19,8 +19,9 @@ class TimelineEntry extends TimelineBaseMethods {
 		/** @type {import("../types").TimelineEntryAll} some properties may not be available yet! */
 		// @ts-ignore
 		this.data = {}
+		const error = new Error("TimelineEntry data was not initalised in same event loop (missing __typename)") // initialise here for a useful stack trace
 		setImmediate(() => { // next event loop
-			if (!this.data.__typename) throw new Error("TimelineEntry data was not initalised in same event loop (missing __typename)")
+			if (!this.data.__typename) throw error
 		})
 		/** @type {string} Not available until fetchExtendedOwnerP is called */
 		this.ownerPfpCacheP = null
@@ -29,8 +30,12 @@ class TimelineEntry extends TimelineBaseMethods {
 	}
 
 	async update() {
-		const data = await collectors.fetchShortcodeData(this.data.shortcode)
+		return collectors.fetchShortcodeData(this.data.shortcode).then(data => {
 			this.applyN3(data)
+		}).catch(error => {
+			console.error("TimelineEntry could not self-update; trying to continue anyway...")
+			console.error("E:", error)
+		})
 	}
 
 	/**

src/lib/utils/body.js

@@ -1,3 +1,4 @@
+const constants = require("../constants")
 const {Parser} = require("./parser/parser")
 
 /**
@@ -5,7 +6,8 @@ const {Parser} = require("./parser/parser")
  */
 function extractSharedData(text) {
 	const parser = new Parser(text)
-	parser.seek("window._sharedData = ", {moveToMatch: true, useEnd: true})
+	const index = parser.seek("window._sharedData = ", {moveToMatch: true, useEnd: true})
+	if (index === -1) throw constants.symbols.NO_SHARED_DATA
 	parser.store()
 	const end = parser.seek(";</script>")
 	parser.restore()

src/site/api/feed.js

@@ -3,8 +3,8 @@ const {fetchUser} = require("../../lib/collectors")
 const {render} = require("pinski/plugins")
 
 module.exports = [
-	{route: `/u/(${constants.external.username_regex})/rss.xml`, methods: ["GET"], code: async ({url, fill}) => {
-		const user = await fetchUser(fill[0])
+	{route: `/u/(${constants.external.username_regex})/rss.xml`, methods: ["GET"], code: ({fill}) => {
+		return fetchUser(fill[0]).then(async user => {
 			const content = await user.timeline.fetchFeed()
 			const xml = content.xml()
 			return {
@@ -12,5 +12,16 @@ module.exports = [
 				contentType: "application/rss+xml", // see https://stackoverflow.com/questions/595616/what-is-the-correct-mime-type-to-use-for-an-rss-feed
 				content: xml
 			}
+		}).catch(error => {
+			if (error === constants.symbols.NOT_FOUND) {
+				return render(404, "pug/friendlyerror.pug", {
+					statusCode: 404,
+					title: "Not found",
+					message: "This user doesn't exist."
+				})
+			} else {
+				throw error
+			}
+		})
 	}}
 ]

src/site/api/routes.js

@@ -4,19 +4,30 @@ const {render} = require("pinski/plugins")
 
 module.exports = [
 	{
-		route: `/u/(${constants.external.username_regex})`, methods: ["GET"], code: async ({url, fill}) => {
+		route: `/u/(${constants.external.username_regex})`, methods: ["GET"], code: ({url, fill}) => {
 			const params = url.searchParams
-			const user = await fetchUser(fill[0])
+			return fetchUser(fill[0]).then(async user => {
 				const page = +params.get("page")
 				if (typeof page === "number" && !isNaN(page) && page >= 1) {
 					await user.timeline.fetchUpToPage(page - 1)
 				}
 				return render(200, "pug/user.pug", {url, user})
+			}).catch(error => {
+				if (error === constants.symbols.NOT_FOUND) {
+					return render(404, "pug/friendlyerror.pug", {
+						statusCode: 404,
+						title: "Not found",
+						message: "This user doesn't exist."
+					})
+				} else {
+					throw error
+				}
+			})
 		}
 	},
 	{
 		route: `/fragment/user/(${constants.external.username_regex})/(\\d+)`, methods: ["GET"], code: async ({url, fill}) => {
-			const user = await fetchUser(fill[0])
+			return fetchUser(fill[0]).then(async user => {
 				const pageNumber = +fill[1]
 				const pageIndex = pageNumber - 1
 				await user.timeline.fetchUpToPage(pageIndex)
@@ -29,14 +40,36 @@ module.exports = [
 						content: "That page does not exist"
 					}
 				}
+			}).catch(error => {
+				if (error === constants.symbols.NOT_FOUND) {
+					return render(404, "pug/friendlyerror.pug", {
+						statusCode: 404,
+						title: "Not found",
+						message: "This user doesn't exist."
+					})
+				} else {
+					throw error
+				}
+			})
 		}
 	},
 	{
-		route: `/p/(${constants.external.shortcode_regex})`, methods: ["GET"], code: async ({fill}) => {
-			const post = await getOrFetchShortcode(fill[0])
+		route: `/p/(${constants.external.shortcode_regex})`, methods: ["GET"], code: ({fill}) => {
+			return getOrFetchShortcode(fill[0]).then(async post => {
 				await post.fetchChildren()
 				await post.fetchExtendedOwnerP() // parallel await is okay since intermediate fetch result is cached
 				return render(200, "pug/post.pug", {post})
+			}).catch(error => {
+				if (error === constants.symbols.NOT_FOUND) {
+					return render(404, "pug/friendlyerror.pug", {
+						statusCode: 404,
+						title: "Not found",
+						message: "Somehow, you reached a post that doesn't exist."
+					})
+				} else {
+					throw error
+				}
+			})
 		}
 	}
 ]

src/site/html/static/js/pagination.js

@@ -36,7 +36,6 @@ class NextPage extends FreezeWidth {
 		fetch(`/fragment/user/${this.element.getAttribute("data-username")}/${this.nextPageNumber}`).then(res => res.text()).then(text => {
 			q("#next-page-container").remove()
 			this.observer.disconnect()
-
 			q("#timeline").insertAdjacentHTML("beforeend", text)
 			addNextPageControl()
 		})

src/site/pug/friendlyerror.pug

@@ -0,0 +1,18 @@
+//- Needs title, message, statusCode
+
+include includes/timeline_page.pug
+include includes/next_page_button.pug
+
+- const numberFormat = new Intl.NumberFormat().format
+
+doctype html
+html
+	head
+		meta(charset="utf-8")
+		meta(name="viewport" content="width=device-width, initial-scale=1")
+		title= `${title} | Bibliogram`
+		link(rel="stylesheet" type="text/css" href="/static/css/main.css")
+	body.error-page
+		h1.code= statusCode
+		p.message= message
+		a(href="javascript:history.back()").back ← Go back?

src/site/sass/main.sass

@@ -242,3 +242,32 @@ body
 
 				&:not(:last-child)
 					margin-bottom: 10px
+
+.error-page
+	min-height: 100vh
+	background: #191919
+	padding: 10px
+	text-align: center
+	display: flex
+	flex-direction: column
+	justify-content: center
+	align-items: center
+
+	.code, .message, .back-link
+		line-height: 1.2
+		margin: 0px
+		color: white
+
+	.code
+		font-size: 80px
+		color: #fff
+		margin-bottom: 25px
+
+	.message
+		font-size: 35px
+		color: #ccc
+		margin-bottom: 15vh
+
+	.back
+		color: #4a93d2
+		font-size: 25px