proof-of-concept(wip): allow custom validator

[jankapunkt]

We all know that this library is on the one hand crucial for modern Meteor Apps, at the same time it's still tightly coupled with SimpleSchema.

This PR is a current proof of concept (not it's work-in-progress status) to make it independent from Simple Schema.

The idea is to be non-breaking for SimpleSchema users but provide all necessary functionality for other validation libs, like zod, ajv etc.

This change requires users to register a "validator" object that implements certain methods. Consider the example for Simple Schema (also located in tests/prepare.js:

import SimpleSchema from "meteor/aldeed:simple-schema";

Collection2.defineValidation({
  name: 'SimpleSchema',
 
  // check if the schema is a schema instance
  is: schema => SimpleSchema.isSimpleSchema(schema),

  // create a new schema instance by definition object
  create: schema => new SimpleSchema(schema),

  // extend the schema, I don't know if other libs support this...
  extend: (s1, s2) => {
    if (s2.version >= 2) {
      const ss = new SimpleSchema(s1);
      ss.extend(s2);
      return ss;
    } else {
      return new SimpleSchema([s1, s2]);
    }
  },

  // mutated cleaning of a doc or modifier, I don't know mofidier support in other libs
  clean: ({ doc, modifier, schema, userId, isLocalCollection, type }) => {
    const isModifier = !Collection2.isInsertType(type);
    const target = isModifier ? modifier : doc;
    schema.clean(target, {
      mutate: true,
      isModifier,
      // We don't do these here because they are done on the client if desired
      filter: false,
      autoConvert: false,
      removeEmptyStrings: false,
      trimStrings: false,
      extendAutoValueContext: {
        isInsert: Collection2.isInsertType(type),
        isUpdate: Collection2.isUpdateType(type),
        isUpsert: Collection2.isUpdateType(type),
        userId,
        isFromTrustedCode: false,
        docId: doc?._id,
        isLocalCollection
      }
    })
  },
  // incomplete yet, will be added once it's implemented
  validate: () => {},

  // the idea is to freeze the validator to avoid any tampering or redefining
  freeze: false
});

The hard part is to extract all Simple-Schema-specific code into this validator without breaking things and at the same time get the abstraction done in a way it will smoothly work with other libs.

Current status:

• simple schema
• ajv
• yup
• zod