feat: allow unions to consolidate into single primitive types

anshchaturvedi commented 1 month ago

This PR aims to introduce a union-consolidation step, where we can simplify union schemas if they meet certain conditions.

Motivation:

We have encountered multiple codecs that type the same A type with different I types. For example, a value intended as a boolean at runtime might be passed into the API as a boolean (true or false), a string ("true" or "false"), or even a number (0 or 1). Currently, dev-portal displays all these options as valid ways to pass a boolean to the API. However, this can be overwhelming and unnecessary for clients. If the API ultimately expects a boolean (typed as t.boolean), we should simplify this by presenting only the primitive boolean type.

Solution: We propose the following criteria for consolidating union schemas into a single primitive type:

The input (I) type is a union.
The runtime (A) type is a primitive type (specifically, string, number, or boolean).
The A type exists literally within the I type.

To support this, we need to address two aspects that are not currently available:

Identifying Primitive Types: Add a primitive property to the schema type to identify primitive io-ts codecs.
Determining Intermediate Types: Add a decodedType property (name can be revised) to the schema type. This will specify the runtime type of codecs like BooleanFromString or NumberFromString, enabling us to determine if a union containing these codecs can be consolidated into a single primitive type.