Add form parser

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@bit-js/byte",
-  "version": "1.6.0",
+  "version": "1.6.1",
   "module": "index.js",
   "devDependencies": {
     "@types/bun": "latest",
@@ -9,7 +9,7 @@
   "type": "module",
   "types": "types/index.d.ts",
   "dependencies": {
-    "@bit-js/blitz": "^1.3.5"
+    "@bit-js/blitz": "^1.3.8"
   },
   "scripts": {
     "build-test": "bun build.ts && bun test && tsc --noEmit -p ./tests/tsconfig.json"

src/plugins/index.ts

@@ -2,3 +2,4 @@
 export * from './server/cors';
 export * from './server/csrf';
 export * from './server/query';
+export * from './server/form';

src/plugins/server/form.ts

@@ -0,0 +1,72 @@
+import { $async, type BaseContext } from "../../core";
+import { noop } from "../../utils/defaultOptions";
+
+interface TypeMap {
+  string: string;
+  number: number;
+  bool: boolean;
+  file: File;
+}
+
+export interface FormPropertyOptions {
+  type: keyof TypeMap;
+  multipleItems?: boolean;
+}
+export type InferFormPropertyOptions<T extends FormPropertyOptions> =
+  T['multipleItems'] extends true ? (TypeMap[T['type']])[] : TypeMap[T['type']];
+
+export type FormSchema = Record<string, FormPropertyOptions>;
+
+export type InferFormSchema<Schema extends FormSchema> = {
+  [K in keyof Schema]: InferFormPropertyOptions<Schema[K]>
+}
+
+export const form = {
+  get<Options extends FormPropertyOptions>(prop: string, { type, multipleItems }: Options): (ctx: BaseContext) => Promise<InferFormPropertyOptions<Options> | null> {
+    return $async(Function(`const p=(f)=>${type === 'string'
+      ? (multipleItems === true
+        ? `{const v=f.getAll(${JSON.stringify(prop)});return v.every((x)=>typeof x==='string')?v:null;}`
+        : `{const v=f.get(${JSON.stringify(prop)});return typeof v==='string'?v:null;}`)
+      : type === 'number'
+        ? (multipleItems === true
+          ? `{const v=f.getAll(${JSON.stringify(prop)}).map((t)=>+t);return v.some(Number.isNaN)?v:null;}`
+          : `{const v=+f.get(${JSON.stringify(prop)});return Number.isNaN(v)?null:v;}`)
+        : type === 'file'
+          ? (multipleItems === true
+            ? `{const v=f.getAll(${JSON.stringify(prop)});return v.every((x)=>x instanceof File)?v:null;}`
+            : `{const v=f.get(${JSON.stringify(prop)});return v instanceof File?v:null;}`)
+          : `f.has(${JSON.stringify(prop)})`
+      };return (c)=>c.req.formData().then(p);`)())
+  },
+
+  schema<Schema extends FormSchema>(schema: Schema): (ctx: BaseContext) => Promise<InferFormSchema<Schema> | null> {
+    const parts: string[] = [''], sets = [];
+
+    for (const key in schema) {
+      const item = schema[key];
+      const { type } = item;
+
+      if (type === 'string') {
+        parts.push(item.multipleItems === true
+          ? `const ${key}=f.getAll(${JSON.stringify(key)});if(${key}.some((x)=>typeof x!=='string'))return null;`
+          : `const ${key}=f.get(${JSON.stringify(key)});if(typeof ${key}!=='string')return null;`
+        );
+        sets.push(key);
+      } else if (type === 'number') {
+        parts.push(item.multipleItems === true
+          ? `const ${key}=f.getAll(${JSON.stringify(key)}).map((t)=>+t);if(${key}.some(Number.isNaN))return null;`
+          : `const ${key}=+f.get(${JSON.stringify(key)});if(Number.isNaN(${key}))return null;`
+        );
+        sets.push(key);
+      } else if (type === 'file') {
+        parts.push(item.multipleItems === true
+          ? `const ${key}=f.getAll(${JSON.stringify(key)});if(${key}.some((x)=>!(x instanceof File)))return null;`
+          : `const ${key}=+f.get(${JSON.stringify(key)});if(!(${key} instanceof File))return null;`
+        );
+      } else
+        sets.push(`${key}:f.has(${JSON.stringify(key)})`);
+    }
+
+    return $async(Function('n', `const p=(f)=>{${parts.join('')}return {${sets}};};return (c)=>c.req.formData().then(p).catch(n);`)(noop));
+  }
+};

src/utils/defaultOptions.ts

@@ -8,3 +8,5 @@ export const default404: Fn = (ctx) => {
     ctx.status = 404;
     return new Response(`Cannot ${ctx.req.method} ${ctx.path}`, ctx as ResponseInit);
 }
+
+export const noop = () => null;

tests/app.ts

@@ -1,5 +1,5 @@
 // Server
-import { Byte, cors, csrf, send } from '@bit-js/byte';
+import { Byte, cors, csrf, send, form } from '@bit-js/byte';
 
 // Basic responses
 export const basicApis = new Byte()
@@ -34,3 +34,4 @@ export const apiWithDefers = new Byte()
 export const apiWithSet = new Byte()
     .set('startTime', performance.now)
     .get('/', (ctx) => ctx.body(performance.now() - ctx.startTime + ''));
+

tests/utils/form.spec.ts

@@ -0,0 +1,57 @@
+import { form, Context } from '@bit-js/byte';
+import { expect, test } from 'bun:test';
+
+function context(obj: Record<string, any>) {
+  const body = new FormData();
+
+  for (const key in obj) {
+    const value = obj[key];
+
+    if (Array.isArray(value)) {
+      for (let i = 0, { length } = value; i < length; ++i) {
+        const item = value[i];
+
+        body.append(key, typeof item === 'string' || item instanceof File ? item : item + '');
+      }
+    } else if (typeof value === 'boolean') {
+      if (value)
+        body.append(key, '');
+    } else body.append(key, typeof value === 'string' || value instanceof File ? value : value + '');
+  }
+
+  return new Context(new Request('http://localhost:3000', {
+    method: 'POST', body
+  }))
+}
+
+test('Form getters', async () => {
+  const parseStr = form.get('name', { type: 'string' });
+  expect(await parseStr(context({ name: 'a' }))).toBe('a');
+  expect(await parseStr(context({ age: 16 }))).toBe(null);
+
+  const parseNum = form.get('id', { type: 'number' });
+  expect(await parseNum(context({ id: 0 }))).toBe(0);
+  expect(await parseNum(context({ id: 'str' }))).toBe(null);
+
+
+  const parseBool = form.get('darkMode', { type: 'bool' });
+  expect(await parseBool(context({ darkMode: '' }))).toBe(true);
+  expect(await parseBool(context({ other: '' }))).toBe(false);
+});
+
+test('Form schema', async () => {
+  const parseForm = form.schema({
+    name: { type: 'string' },
+    age: { type: 'number' },
+    darkMode: { type: 'bool' },
+    ids: { type: 'number', multipleItems: true }
+  });
+
+  const o1 = {
+    name: 'dave',
+    age: 18,
+    darkMode: true,
+    ids: [5, 6]
+  };
+  expect(await parseForm(context(o1))).toEqual(o1);
+});