Support extracting of type information from tagged templates

[okonet]

It looks like even if I have a resolver that resolves to components that use tagged templates like styled-components, the type annotations aren't extracted.

Consider the following example:

import styled from "styled-components";

interface FlexProps {
    bool: boolean
}

const Flex = styled('div')<FlexProps>`
    display: flex;
`;

/** @component */
export default Flex;

When used with an react-docgen-annotation-resolver, the type definitions won't be extracted.

I scoped it to this place in code that's responsible for finding type annotations: https://github.com/okonet/react-docgen/blob/8fb401089e3fe2b38d41638bc5690436e23aceb3/src/utils/getTypeAnnotation.js#L22

and it looks like it's searching for specific key typeAnnotation in the AST. For styled-component example, though, it won't present. But what's going to present is

Node {
     type: 'TaggedTemplateExpression',
     start: 95,
     end: 138,
     loc: SourceLocation { start: [Position], end: [Position] },
     tag:
      Node {
        type: 'CallExpression',
        start: 95,
        end: 108,
        loc: [SourceLocation],
        callee: [Node],
        arguments: [Array] },
     quasi:
      Node {
        type: 'TemplateLiteral',
        start: 119,
        end: 138,
        loc: [SourceLocation],
        expressions: [],
        quasis: [Array] },
     typeParameters:
      Node {
        type: 'TSTypeParameterInstantiation',
        start: 108,
        end: 119,
        loc: [SourceLocation],
        params: [Array] } },

So, it looks like there is something related to types in there but its not being properly handled.

Does anyone has any pointers on how to fix it?

[okonet]

@pvasek could you help since I think you did this already once.

[smashercosmo]

Another problem is that type definitions are only extracted from class or functional components https://github.com/reactjs/react-docgen/blob/master/src/utils/getFlowTypeFromReactComponent.js#L28-L50