Fix source mapping for codegenNativeCommands

[vzaidman]

Summary:
babel-plugin-codegen transforms codegenNativeComponents by expending it with a whole set of many commands (~40 lines) that don't have a good equivalent on the source file.

Currently these lines are pointing to random parts of the due to a bug that causes the source maps to be incorrect and confusing.

Instead, I point all these generated lines of code to the default export as the only line that can represent them.

This way, if an error is thrown from that generated code it would point to that export.

If the users are confused by how it works, there's a comment in the function that is used in the default export in these that explains it:

// If this function runs then that means the view configs were not
// generated at build time using `GenerateViewConfigJs.js`. Thus
// we need to `requireNativeComponent` to get the view configs from view managers.
// `requireNativeComponent` is not available in Bridgeless mode.
// e.g. This function runs at runtime if `codegenNativeComponent` was not called
// from a file suffixed with NativeComponent.js.
function codegenNativeComponent<Props>(
  componentName: string,
  options?: Options,
): NativeComponentType<Props> {

The transformation is from all the types and exports after the imports:
MyNativeViewNativeComponent for example
Which is roughly (ignoring all typing):

// types and exports
export const Commands: NativeCommands = codegenNativeCommands<NativeCommands>({
  supportedCommands: [
    'callNativeMethodToChangeBackgroundColor',
    'callNativeMethodToAddOverlays',
    'callNativeMethodToRemoveOverlays',
    'fireLagacyStyleEvent',
  ],
});

export default (codegenNativeComponent<NativeProps>(
  'RNTMyNativeView',
): MyNativeViewType);

to roughly:

  var React = require('react');
  var nativeComponentName = 'RNTMyNativeView';
  var __INTERNAL_VIEW_CONFIG = {
    uiViewClassName: 'RNTMyNativeView',
    bubblingEventTypes: {
      topIntArrayChanged: { /* */ },
      topAlternativeLegacyName: { /* */ },
    },
    validAttributes: {
      opacity: true,
      values: true,
      ...require('ViewConfigIgnore').ConditionallyIgnoredEventHandlers({
        onIntArrayChanged: true,
        onLegacyStyleEvent: true
      })
    }
  };
  var _default = require('NativeComponentRegistry').get(nativeComponentName, () => __INTERNAL_VIEW_CONFIG);
  var Commands = {
    callNativeMethodToChangeBackgroundColor(ref, color) {
      require('RendererProxy').dispatchCommand(ref, "callNativeMethodToChangeBackgroundColor", [color]);
    },
    callNativeMethodToAddOverlays(ref, overlayColors) {
     require('RendererProxy').dispatchCommand(ref, "callNativeMethodToAddOverlays", [overlayColors]);
    },
    callNativeMethodToRemoveOverlays(ref) {
      require('RendererProxy').dispatchCommand(ref, "callNativeMethodToRemoveOverlays", []);
    },
    fireLagacyStyleEvent(ref) {
     require('RendererProxy').dispatchCommand(ref, "fireLagacyStyleEvent", []);
    }
  };
  exports.default = _default;
  exports.__INTERNAL_VIEW_CONFIG = __INTERNAL_VIEW_CONFIG;
  exports.Commands = Commands;

Changelog: [Fix] Fixed source maps in Native Components JS files that use codegenNativeComponent

Differential Revision: D62443699

[facebook-github-bot]

This pull request was exported from Phabricator. Differential Revision: D62443699

[facebook-github-bot]

This pull request was exported from Phabricator. Differential Revision: D62443699

[facebook-github-bot]

This pull request was exported from Phabricator. Differential Revision: D62443699

[facebook-github-bot]

This pull request was exported from Phabricator. Differential Revision: D62443699

[facebook-github-bot]

This pull request was exported from Phabricator. Differential Revision: D62443699

[facebook-github-bot]

This pull request has been merged in 8fba154.

[react-native-bot]

This pull request was successfully merged by @vzaidman in 8fba154

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