如何使用 typescript compile api 生成装饰器

Question

I want to generate a class whose members has more than one 'class-validator' Decorator to check the type of property. I think i can use ts.factory.createDecorator to do that, but how can i get a ts.Expression?

Answer 1

found this, check maybe will be helpfull for you

/* output 
@niceDecorator(“bar”)
class foo {
}
*/
const p = ts.createIdentifier(‘niceDecorator’);
const call = ts.createCall(p, undefined, [str]);
const dec = ts.createDecorator(call);
const classDec = ts.createClassDeclaration([dec], undefined, ‘foo’, undefined, undefined, undefined);

I'm trying to do the same, couldn't find how to make it.

as for code example (which is not working):

const newMembers = node.members.map(propertyNode => {
        if(ts.isPropertyDeclaration(propertyNode)) {
          const newDecorators = [...propertyNode.decorators];
          if (propertyNode.type.kind === 149) {
            // STRING ts.SyntaxKind[kind]
            const newExpression = ts.factory.createDecorator(
                    {
                      _expressionBrand: 'IsString',
                    }
            )
            newDecorators.push({
              kind: ts.SyntaxKind.Decorator,
              parent: propertyNode,
              expression: newExpression,
            });
          }
          const updRes = ts.factory.updatePropertyDeclaration(
                  propertyNode,
                  newDecorators,
                  propertyNode.modifiers,
                  propertyNode.name,
                  undefined,
                  propertyNode.type,
                  propertyNode.initializer
          )
          return updRes;
        }
        const updClassRes = ts.factory.updateClassDeclaration(
                node,
                node.decorators,
                node.modifiers,
                node.name,
                node.typeParameters,
                node.heritageClauses,
                newMembers
        )