feat: extend complex formdata support to StandardSchema

example/nested-multipart-files.ts

@@ -0,0 +1,99 @@
+import { Elysia, t } from '../src'
+
+/**
+ * Example: Nested File Uploads with Multipart Forms
+ *
+ * Elysia supports nested file uploads using dot notation in multipart forms.
+ * This allows you to organize files and data in a nested structure while
+ * still using standard multipart/form-data encoding.
+ *
+ * How it works:
+ * 1. Client sends files with dot notation keys (e.g., "user.avatar")
+ * 2. Elysia automatically reconstructs the nested object structure
+ * 3. Your handler receives a properly nested object
+ */
+
+const app = new Elysia()
+	// Basic nested file upload
+	.post(
+		'/user/profile',
+		({ body }) => ({
+			message: 'Profile created!',
+			user: {
+				name: body.user.name,
+				avatarSize: body.user.avatar.size
+			}
+		}),
+		{
+			body: t.Object({
+				user: t.Object({
+					name: t.String(),
+					avatar: t.File()
+				})
+			})
+		}
+	)
+
+	// Deeply nested files
+	.post(
+		'/user/portfolio',
+		({ body }) => ({
+			bio: body.user.profile.bio,
+			photoCount: body.user.profile.photos.length
+		}),
+		{
+			body: t.Object({
+				user: t.Object({
+					profile: t.Object({
+						bio: t.String(),
+						photos: t.Files()
+					})
+				})
+			})
+		}
+	)
+
+	// Mixed flat and nested fields
+	.post(
+		'/post',
+		({ body }) => ({
+			title: body.title,
+			authorName: body.author.name,
+			imageSize: body.author.avatar.size
+		}),
+		{
+			body: t.Object({
+				title: t.String(),
+				author: t.Object({
+					name: t.String(),
+					avatar: t.File()
+				})
+			})
+		}
+	)
+	.listen(3000)
+
+console.log(`🦊 Server running at http://${app.server?.hostname}:${app.server?.port}`)
+
+/**
+ * Client-side usage (with fetch):
+ *
+ * const formData = new FormData()
+ * formData.append('user.name', 'John')
+ * formData.append('user.avatar', fileBlob)
+ *
+ * await fetch('http://localhost:3000/user/profile', {
+ *   method: 'POST',
+ *   body: formData
+ * })
+ *
+ *
+ * Eden client usage (future):
+ *
+ * await client.user.profile.post({
+ *   user: {
+ *     name: 'John',
+ *     avatar: fileBlob  // Eden will flatten this automatically
+ *   }
+ * })
+ */

src/adapter/web-standard/index.ts

@@ -48,12 +48,79 @@ export const WebStandardAdapter: ElysiaAdapter = {
 
 				return (
 					fnLiteral +
+					`const dangerousKeys=new Set(['__proto__','constructor','prototype'])\n` +
+					`const isDangerousKey=(k)=>{` +
+					`if(dangerousKeys.has(k))return true;` +
+					`const m=k.match(/^(.+)\\[(\\d+)\\]$/);` +
+					`return m?dangerousKeys.has(m[1]):false` +
+					`}\n` +
+					`const parseArrayKey=(k)=>{` +
+					`const m=k.match(/^(.+)\\[(\\d+)\\]$/);` +
+					`return m?{name:m[1],index:parseInt(m[2],10)}:null` +
+					`}\n` +
 					`for(const key of form.keys()){` +
-					`if(c.body[key]) continue\n` +
+					`if(c.body[key])continue\n` +
 					`const value=form.getAll(key)\n` +
-					`if(value.length===1)` +
-					`c.body[key]=value[0]\n` +
-					`else c.body[key]=value` +
+					`let finalValue\n` +
+    				`if(value.length===1){\n` +
+    				`const sv=value[0]\n` +
+    				`if(typeof sv==='string'&&(sv.charCodeAt(0)===123||sv.charCodeAt(0)===91)){\n` +
+    				`try{\n` +
+    				`const p=JSON.parse(sv)\n` +
+    				`if(p&&typeof p==='object')finalValue=p\n` +
+    				`}catch{}\n` +
+    				`}\n` +
+    				`if(finalValue===undefined)finalValue=sv\n` +
+    				`}else finalValue=value\n` +
+					`if(Array.isArray(finalValue)){\n` +
+					`const stringValue=finalValue.find((entry)=>typeof entry==='string')\n` +
+					`const files=typeof File==='undefined'?[]:finalValue.filter((entry)=>entry instanceof File)\n` +
+					`if(stringValue&&files.length&&stringValue.charCodeAt(0)===123){\n` +
+					`try{\n` +
+					`const parsed=JSON.parse(stringValue)\n` +
+					`if(parsed&&typeof parsed==='object'&&!Array.isArray(parsed)){\n` +
+					`if(!('file' in parsed)&&files.length===1)parsed.file=files[0]\n` +
+					`else if(!('files' in parsed)&&files.length>1)parsed.files=files\n` +
+					`finalValue=parsed\n` +
+					`}\n` +
+					`}catch{}\n` +
+					`}\n` +
+					`}\n` +
+					`if(key.includes('.')||key.includes('[')){` +
+					`const keys=key.split('.')\n` +
+					`const lastKey=keys.pop()\n` +
+					`if(isDangerousKey(lastKey)||keys.some(isDangerousKey))continue\n` +
+					`let current=c.body\n` +
+					`for(const k of keys){` +
+					`const arrayInfo=parseArrayKey(k)\n` +
+					`if(arrayInfo){` +
+					`if(!Array.isArray(current[arrayInfo.name]))current[arrayInfo.name]=[]\n` +
+					`const existing=current[arrayInfo.name][arrayInfo.index]\n` +
+					`const isFile=typeof File!=='undefined'&&existing instanceof File\n` +
+					`if(!existing||typeof existing!=='object'||Array.isArray(existing)||isFile){\n` +
+					`let parsed\n` +
+					`if(typeof existing==='string'&&existing.charCodeAt(0)===123){\n` +
+					`try{` +
+					`parsed=JSON.parse(existing)\n` +
+					`if(!parsed||typeof parsed!=='object'||Array.isArray(parsed))parsed=undefined` +
+					`}catch{}\n` +
+					`}\n` +
+					`current[arrayInfo.name][arrayInfo.index]=parsed||{}\n` +
+					`}\n` +
+					`current=current[arrayInfo.name][arrayInfo.index]` +
+					`}else{` +
+					`if(!current[k]||typeof current[k]!=='object')current[k]={}\n` +
+					`current=current[k]` +
+					`}` +
+					`}\n` +
+					`const arrayInfo=parseArrayKey(lastKey)\n` +
+					`if(arrayInfo){` +
+					`if(!Array.isArray(current[arrayInfo.name]))current[arrayInfo.name]=[]\n` +
+					`current[arrayInfo.name][arrayInfo.index]=finalValue` +
+					`}else{` +
+					`current[lastKey]=finalValue` +
+					`}` +
+					`}else c.body[key]=finalValue` +
 					`}`
 				)
 			}
@@ -125,7 +192,10 @@ export const WebStandardAdapter: ElysiaAdapter = {
 		},
 		error404(hasEventHook, hasErrorHook, afterHandle = '') {
 			let findDynamicRoute =
-				`if(route===null){` + afterHandle + (hasErrorHook ? '' : 'c.set.status=404') + '\nreturn '
+				`if(route===null){` +
+				afterHandle +
+				(hasErrorHook ? '' : 'c.set.status=404') +
+				'\nreturn '
 
 			if (hasErrorHook)
 				findDynamicRoute += `app.handleError(c,notFound,false,${this.parameters})`