Example of a way to compose a chain of methods conditionally for libraries that use method chaining

method-chaining-composition.js

const compose = funcObjects => startingInstance =>
  funcObjects.reduce(
    (composed, currentFunc) =>
      composed[currentFunc.method](currentFunc.argument),
    startingInstance
  );

// Example of how compose would be called with static data
// const emailComposed = compose(
//   { method: "email", argument: "Enter an email, tallywacker." },
//   { method: "required", argument: "I AM Required Message." },
// )(Yup.string())

const data = [
  {
    htmlName: "email",
    fieldType: "string",
    validations: [
      { requiredType: "email", errorMessage: "EMAIL DUMMY" },
      { requiredType: "required", errorMessage: "I AM required Message." }
    ]
  }
];

const composeValidation = (type, validations) => {
  const formattedForComposition = validations.map(validation => {
    return {
      method: validation.requiredType,
      argument: validation.errorMessage
    };
  });

  return compose(formattedForComposition)(Yup[type]());
};

// Yup.string().email().required("message")
const validationSchema = data.reduce((acc, cur) => {
  acc[cur.htmlName] = composeValidation(cur.fieldType, cur.validations);
  return acc;
}, {});

// Which is used like so:
Yup.object().shape(validationSchema)