restfuncs-transformer

This transformer prepares ServerSession subclasses for Typia and adds jsDoc info for the (upcoming) API browser.

Usage

Here's how to use it

How the transformer chain works

Here is, how the restfuncs-transformer, typia transformer and typescript-rtti work together:

1. The restfuncs-transformer scans for all @remote methods and, at the bottom of inside their class, it adds the following code (here for "myMethod"):

/**
 * Code is generated by the restfuncs-transformer during compile-time
 */
static getRemoteMethodsMeta(): (typeof this.type_remoteMethodsMeta) {
    this.__hello_developer__make_sure_your_class_is_a_subclass_of_ServerSession // Give a friendly error message when this is not the case. Otherwise the following statement "const typia = ..." would fail and leaves the user wondering.
    let typia = this.typiaRuntime; // We need a "typia" defined in the scope, but let restfuncs manage where that dependency comes from
    return {
        transformerVersion: {major: XX,  feature: XX },
        instanceMethods: {
            "myMethod": {
                arguments: {
                    validateEquals: (args: unknown) => typia.validateEquals<Parameters<typeof this.prototype["myMethod"]>>(args),
                    validatePrune: ...
                },
                result: {
                    validateEquals: (value: unknown) => typia.validateEquals<Awaited<ReturnType<typeof this.prototype["myMethod"]>>>(value),
                    ...
                },
                jsDoc: {
                    comment: "text with <strong>markup</strong>", 
                    params: {a: "text..."},
                    tags: [{name:"returns", comment: "text..."}]
                }
            }
        }
    }
}

2. The Typia transformer will then replace all typia.validate<T> expressions with the actual validation code body. Typia calls this "ahead of time validation". At runtime this is used to validate evil input and serialize/deserialize from json/protobuf in an ultra fast way (future).
3. The typescript-rtti transformer adds type-info decorations for all compiled symbols (that's all this __RΦ stuff in the .js). At runtime, this allows restfuncs to easily navigate through- and inspect all the type hierarchy. I.e when mapping REST parameter names to the remote methods arguments, for better error diagnosis, or for the upcoming API browser.