feat: /preview

wevm · Feb 7, 2024 · 297bab0 · 297bab0
1 parent db93929
commit 297bab0
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Showing 6 changed files with 244 additions and 60 deletions.
diff --git a/biome.json b/biome.json
@@ -25,5 +25,12 @@
         "noUselessFragments": "off"
       }
     }
+  },
+  "javascript": {
+    "formatter": {
+      "quoteStyle": "single",
+      "trailingComma": "all",
+      "semicolons": "asNeeded"
+    }
   }
 }
diff --git a/bun.lockb b/bun.lockb
diff --git a/package.json b/package.json
@@ -1,6 +1,7 @@
 {
   "workspaces": ["example", "src"],
   "scripts": {
+    "dev": "bun run --hot ./example/src/index.tsx",
     "build": "bun run clean && tsc --project ./tsconfig.build.json",
     "changeset": "changeset",
     "changeset:release": "bun run build && changeset publish",

diff --git a/src/index.tsx b/src/index.tsx
@@ -1,33 +1,68 @@
-import { type Context, Hono } from "hono";
-import { ImageResponse } from "hono-og";
-import { type JSXNode } from "hono/jsx";
+import { type Context, Hono } from 'hono'
+import { ImageResponse } from 'hono-og'
+import { type JSXNode } from 'hono/jsx'
+import { Window } from 'happy-dom'
+import { jsxRenderer } from 'hono/jsx-renderer'
+
+import {
+  type Frame,
+  type FrameButton,
+  type FrameMetaTagPropertyName,
+  type FrameVersion,
+} from './types.js'
 
 type FrameContext = Context & {
-  trustedData?: { messageBytes: string };
+  trustedData?: { messageBytes: string }
   untrustedData?: {
-    fid: number;
-    url: string;
-    messageHash: string;
-    timestamp: number;
-    network: number;
-    buttonIndex?: 1 | 2 | 3 | 4;
-    castId: { fid: number; hash: string };
-    inputText?: string;
-  };
-};
+    fid: number
+    url: string
+    messageHash: string
+    timestamp: number
+    network: number
+    buttonIndex?: 1 | 2 | 3 | 4
+    castId: { fid: number; hash: string }
+    inputText?: string
+  }
+}
 
 type FrameReturnType = {
-  image: JSX.Element;
-  intents: JSX.Element;
-};
+  image: JSX.Element
+  intents: JSX.Element
+}
 
 export class Framework extends Hono {
   frame(
     path: string,
     handler: (c: FrameContext) => FrameReturnType | Promise<FrameReturnType>,
   ) {
+    this.get(
+      '/preview',
+      jsxRenderer(
+        ({ children }) => {
+          return (
+            <html lang="en">
+              <body>{children}</body>
+            </html>
+          )
+        },
+        { docType: true },
+      ),
+    )
+
+    this.get('/preview', async (c) => {
+      const baseUrl = c.req.url.replace(c.req.path, '')
+      const response = await fetch(baseUrl)
+      const html = await response.text()
+      const frame = htmlToFrame(html)
+      return c.render(
+        <div>
+          <img alt="Farcaster frame" src={frame.imageUrl} />
+        </div>,
+      )
+    })
+
     this.get(path, async (c) => {
-      const { intents } = await handler(c);
+      const { intents } = await handler(c)
       return c.render(
         <html lang="en">
           <head>
@@ -38,18 +73,18 @@ export class Framework extends Hono {
             {parseIntents(intents)}
           </head>
         </html>,
-      );
-    });
+      )
+    })
 
     // TODO: don't slice
     this.get(`${path.slice(1)}_og`, async (c) => {
-      const { image } = await handler(c);
-      return new ImageResponse(image);
-    });
+      const { image } = await handler(c)
+      return new ImageResponse(image)
+    })
 
     this.post(path, async (c) => {
-      const context = await parsePostContext(c);
-      const { intents } = await handler(context);
+      const context = await parsePostContext(c)
+      const { intents } = await handler(context)
       return c.render(
         <html lang="en">
           <head>
@@ -60,57 +95,154 @@ export class Framework extends Hono {
             {parseIntents(intents)}
           </head>
         </html>,
-      );
-    });
+      )
+    })
   }
 }
 
 ////////////////////////////////////////////////////////////////////////
 // Components
 
 export type ButtonProps = {
-  children: string;
-};
+  children: string
+}
 
 export function Button({ children }: ButtonProps) {
-  return <meta property="fc:frame:button" content={children} />;
+  return <meta property="fc:frame:button" content={children} />
 }
 
 ////////////////////////////////////////////////////////////////////////
 // Utilities
 
-type Counter = { button: number };
+type Counter = { button: number }
 
 async function parsePostContext(ctx: Context): Promise<FrameContext> {
   const { trustedData, untrustedData } =
-    (await ctx.req.json().catch(() => {})) || {};
-  return Object.assign(ctx, { trustedData, untrustedData });
+    (await ctx.req.json().catch(() => {})) || {}
+  return Object.assign(ctx, { trustedData, untrustedData })
 }
 
 function parseIntents(intents_: JSX.Element) {
-  const intents = intents_ as unknown as JSXNode;
+  const intents = intents_ as unknown as JSXNode
   const counter: Counter = {
-    button: 0,
-  };
+    button: 1,
+  }
 
-  if (typeof intents.children[0] === "object")
+  if (typeof intents.children[0] === 'object')
     return Object.assign(intents, {
       children: intents.children.map((e) => parseIntent(e as JSXNode, counter)),
-    });
-  return parseIntent(intents, counter);
+    })
+  return parseIntent(intents, counter)
 }
 
 function parseIntent(node: JSXNode, counter: Counter) {
   const intent = (
-    typeof node.tag === "function" ? node.tag({}) : node
-  ) as JSXNode;
+    typeof node.tag === 'function' ? node.tag({}) : node
+  ) as JSXNode
+
+  const props = intent.props || {}
+
+  if (props.property === 'fc:frame:button') {
+    props.property = `fc:frame:button:${counter.button++}`
+    props.content = node.children
+  }
 
-  const props = intent.props || {};
+  return Object.assign(intent, { props })
+}
 
-  if (props.property === "fc:frame:button") {
-    props.property = `fc:frame:button:${counter.button++}`;
-    props.content = node.children;
+function htmlToFrame(html: string) {
+  const window = new Window()
+  window.document.write(html)
+  const document = window.document
+  const metaTags = document.querySelectorAll(
+    'meta',
+  ) as unknown as readonly HTMLMetaElement[]
+
+  const validPropertyNames = new Set<FrameMetaTagPropertyName>([
+    'fc:frame',
+    'fc:frame:image',
+    'fc:frame:input:text',
+    'fc:frame:post_url',
+    'og:image',
+    'og:title',
+  ])
+  // https://regexr.com/7rlm0
+  const buttonRegex = /fc:frame:button:(1|2|3|4)(?::(action|target))?$/
+
+  let currentButtonIndex = 0
+  let buttonsAreMissing = false
+  let buttonsAreOutOfOrder = false
+  const buttonMap = new Map<number, Omit<FrameButton, 'type'>>()
+  const buttonActionMap = new Map<number, FrameButton['type']>()
+  const invalidButtons: FrameButton['index'][] = []
+
+  const properties: Partial<Record<FrameMetaTagPropertyName, string>> = {}
+  for (const metaTag of metaTags) {
+    const property = metaTag.getAttribute(
+      'property',
+    ) as FrameMetaTagPropertyName | null
+    if (!property) continue
+
+    const content = metaTag.getAttribute('content') ?? ''
+    if (validPropertyNames.has(property)) properties[property] = content
+    else if (buttonRegex.test(property)) {
+      const matchArray = property.match(buttonRegex) as [
+        string,
+        string,
+        string | undefined,
+      ]
+      const index = parseInt(matchArray[1], 10) as FrameButton['index']
+      const type = matchArray[2] as FrameButton['type'] | undefined
+
+      if (type) buttonActionMap.set(index, content as FrameButton['type'])
+      else {
+        if (currentButtonIndex >= index) buttonsAreOutOfOrder = true
+        if (currentButtonIndex + 1 === index) currentButtonIndex = index
+        else buttonsAreMissing = true
+
+        if (buttonsAreOutOfOrder || buttonsAreMissing)
+          invalidButtons.push(index)
+
+        const title = content ?? index
+        buttonMap.set(index, { index, title })
+      }
+    }
   }
 
-  return Object.assign(intent, { props });
+  const image = properties['og:image'] ?? ''
+  const imageUrl = properties['fc:frame:image'] ?? ''
+  const postUrl = properties['fc:frame:post_url'] ?? ''
+  const title = properties['og:title'] ?? ''
+  const version = (properties['fc:frame'] as FrameVersion) ?? 'vNext'
+
+  let buttons = [] as FrameButton[]
+  for (const [index, button] of buttonMap) {
+    buttons.push({
+      ...button,
+      type: buttonActionMap.get(index) ?? 'post',
+    })
+  }
+  buttons = buttons.toSorted((a, b) => a.index - b.index)
+
+  const fallbackImageToUrl = !imageUrl
+  const postUrlTooLong = postUrl.length > 2_048
+  // TODO: Figure out how this is determined
+  // https://warpcast.com/~/developers/frames
+  const valid = true
+
+  const frame = { buttons, imageUrl, postUrl, version }
+  return {
+    ...frame,
+    debug: {
+      ...frame,
+      buttonsAreOutOfOrder: buttonsAreMissing || buttonsAreOutOfOrder,
+      fallbackImageToUrl,
+      htmlTags: metaTags.map((x) => x.outerHTML),
+      image,
+      invalidButtons,
+      postUrlTooLong,
+      valid,
+    },
+    title,
+  } satisfies Frame
 }
diff --git a/src/package.json b/src/package.json
@@ -1,18 +1,19 @@
 {
-	"name": "@wevm/framework",
-	"version": "0.0.0",
-	"type": "module",
-	"module": "_lib/index.js",
-	"types": "_lib/index.d.ts",
-	"typings": "_lib/index.d.ts",
-	"sideEffects": false,
-	"exports": {
+  "name": "@wevm/framework",
+  "version": "0.0.0",
+  "type": "module",
+  "module": "_lib/index.js",
+  "types": "_lib/index.d.ts",
+  "typings": "_lib/index.d.ts",
+  "sideEffects": false,
+  "exports": {
     ".": "./_lib/index.js"
   },
-	"peerDependencies": {
-		"hono": "^3"
-	},
-	"dependencies": {
-		"hono-og": "~0.0.2"
-	}
+  "peerDependencies": {
+    "hono": "^3"
+  },
+  "dependencies": {
+    "happy-dom": "^13.3.8",
+    "hono-og": "~0.0.2"
+  }
 }
diff --git a/src/types.ts b/src/types.ts
@@ -0,0 +1,43 @@
+// TODO: TSDoc
+
+export type Frame = {
+  buttons?: readonly FrameButton[] | undefined
+  debug?: FrameDebug | undefined
+  imageUrl: string
+  postUrl: string
+  title: string
+  version: FrameVersion
+}
+
+export type FrameDebug = {
+  buttons?: readonly FrameButton[] | undefined
+  buttonsAreOutOfOrder: boolean
+  fallbackImageToUrl: boolean
+  htmlTags: readonly string[]
+  image: string
+  imageUrl: string
+  invalidButtons: readonly FrameButton['index'][]
+  postUrl: string
+  postUrlTooLong: boolean
+  valid: boolean
+  version: FrameVersion
+}
+
+export type FrameButton = {
+  index: 1 | 2 | 3 | 4
+  title: string
+  type: 'post' | 'post_redirect'
+}
+
+export type FrameVersion = 'vNext'
+
+export type FrameMetaTagPropertyName =
+  | 'fc:frame'
+  | 'fc:frame:image'
+  | 'fc:frame:input:text'
+  | 'fc:frame:post_url'
+  | 'og:image'
+  | 'og:title'
+  | `fc:frame:button:${FrameButton['index']}:action`
+  | `fc:frame:button:${FrameButton['index']}:target`
+  | `fc:frame:button:${FrameButton['index']}`