@nestia/core/src/programmers/http/HttpQuerifyProgrammer.ts

Super-fast validation decorators of NestJS

import {
  FunctionProgrammer,
  HttpQueryProgrammer,
  ITypiaContext,
  IdentifierFactory,
  MetadataCollection,
  MetadataFactory,
  MetadataObject,
  MetadataSchema,
  StatementFactory,
  TransformerError,
} from "@typia/core";
import ts from "typescript";

export namespace HttpQuerifyProgrammer {
  export const write = (props: {
    context: ITypiaContext;
    modulo: ts.LeftHandSideExpression;
    type: ts.Type;
  }): ts.ArrowFunction => {
    // GET OBJECT TYPE
    const functor: FunctionProgrammer = new FunctionProgrammer(
      props.modulo.getText(),
    );
    const storage: MetadataCollection = new MetadataCollection();
    const result = MetadataFactory.analyze({
      checker: props.context.checker,
      transformer: props.context.transformer,
      options: {
        escape: false,
        constant: true,
        absorb: true,
        validate: HttpQueryProgrammer.validate,
      },
      type: props.type,
      components: storage,
    });
    if (result.success === false)
      throw TransformerError.from({
        code: functor.method,
        errors: result.errors,
      });

    const object: MetadataObject = result.data.objects[0]!;
    return ts.factory.createArrowFunction(
      undefined,
      undefined,
      [IdentifierFactory.parameter("input")],
      undefined,
      undefined,
      ts.factory.createBlock(
        [
          ...functor.declare(),
          StatementFactory.constant({
            name: "output",
            value: ts.factory.createNewExpression(
              ts.factory.createIdentifier("URLSearchParams"),
              undefined,
              [],
            ),
          }),
          ...object.type.properties.map((p) =>
            ts.factory.createExpressionStatement(
              decode(p.key.constants[0]!.values[0]!.value as string)(p.value),
            ),
          ),
          ts.factory.createReturnStatement(
            ts.factory.createIdentifier("output"),
          ),
        ],
        true,
      ),
    );
  };

  const decode =
    (key: string) =>
    (value: MetadataSchema): ts.CallExpression =>
      !!value.arrays.length
        ? ts.factory.createCallExpression(
            IdentifierFactory.access(
              IdentifierFactory.access(
                ts.factory.createIdentifier("input"),
                key,
              ),
              "forEach",
            ),
            undefined,
            [
              ts.factory.createArrowFunction(
                undefined,
                undefined,
                [IdentifierFactory.parameter("elem")],
                undefined,
                undefined,
                append(key)(ts.factory.createIdentifier("elem")),
              ),
            ],
          )
        : append(key)(
            IdentifierFactory.access(ts.factory.createIdentifier("input"), key),
          );

  const append = (key: string) => (elem: ts.Expression) =>
    ts.factory.createCallExpression(
      IdentifierFactory.access(ts.factory.createIdentifier("output"), "append"),
      undefined,
      [ts.factory.createStringLiteral(key), elem],
    );
}