schema-dsl
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      • SchemaUtils usage guide

      Schema reuse and conversion tools

      quick start

      4 methods to reuse Schema:

      import { s, SchemaUtils } from 'schema-dsl/pure';

const userSchema = s({
  id: 'objectId!',
  name: 'string!',
  email: 'email!',
  password: 'string!',
  age: 'integer:18-120'
});

// exclude fields
SchemaUtils.omit(userSchema, ['password']);

// reserved fields
SchemaUtils.pick(userSchema, ['name', 'email']);

// become optional
SchemaUtils.partial(userSchema);

//Extended fields
SchemaUtils.extend(userSchema, { avatar: 'url' });

      omit - exclude fields

      // Create user - exclude system fields
const createSchema = SchemaUtils.omit(userSchema, ['id', 'createdAt']);

// Public information - exclude sensitive fields
const publicSchema = SchemaUtils.omit(userSchema, ['password']);

      pick - reserved fields

      // Only some fields are allowed to be modified
const updateSchema = SchemaUtils.pick(userSchema, ['name', 'age']);

      partial - becomes optional

      // All fields become optional
const partialSchema = SchemaUtils.partial(userSchema);

      extend - extend field

      //Add new field
const extendedSchema = SchemaUtils.extend(userSchema, {
  avatar: 'url',
  bio: 'string:0-500'
});

      chain call

      // pick + partial
SchemaUtils.pick(userSchema, ['name', 'age']).partial();

// pick + extend
SchemaUtils.pick(userSchema, ['name']).extend({ avatar: 'url' });

      Express example

      import { s, SchemaUtils, validateAsync } from 'schema-dsl/pure';

const userSchema = s({
  id: 'objectId!',
  name: 'string!',
  email: 'email!',
  password: 'string!',
  age: 'integer:18-120'
});

// POST /users - create
app.post('/users', async (req, res, next) => {
  const schema = SchemaUtils.omit(userSchema, ['id']);
  const data = await validateAsync(schema, req.body);
  // Save to database...
});

// GET /users/:id - Query
app.get('/users/:id', async (req, res) => {
  const schema = SchemaUtils.omit(userSchema, ['password']);
  const user = await db.findById(req.params.id);
  const result = validate(schema, user);
  res.json(result.data);
});

// PATCH /users/:id - update
app.patch('/users/:id', async (req, res, next) => {
  const schema = SchemaUtils.pick(userSchema, ['name', 'age']).partial();
  const data = await validateAsync(schema, req.body);
  //Update database...
});

      API

      omit(schema, fields)

      exclude fields

      pick(schema, fields)

      reserved fields

      partial(schema, fields?)

      become optional

      extend(schema, extensions)

      extension fields

      Corresponding sample file

      Example entry: schema-utils-chaining.ts Description: Covers the chain combination of omit(), extend(), pick(), partial(), and the success/failure validation path of the derived schema.