Parse a module.export object in storybook cli

parse-module-exports.md

https://github.com/storybookjs/storybook/blob/7035ea7389393da041985ebc491ee58dedb50d06/code/lib/csf-tools/src/ConfigFile.ts#L100-L159

  parse() {
    // eslint-disable-next-line @typescript-eslint/no-this-alias
    const self = this;
    traverse(this._ast, {
      ExportNamedDeclaration: {
        enter({ node, parent }) {
          if (t.isVariableDeclaration(node.declaration)) {
            // export const X = ...;
            node.declaration.declarations.forEach((decl) => {
              if (t.isVariableDeclarator(decl) && t.isIdentifier(decl.id)) {
                const { name: exportName } = decl.id;
                let exportVal = decl.init;
                if (t.isIdentifier(exportVal)) {
                  exportVal = _findVarInitialization(exportVal.name, parent as t.Program);
                }
                self._exports[exportName] = exportVal;
              }
            });
          } else {
            logger.warn(`Unexpected ${JSON.stringify(node)}`);
          }
        },
      },
      ExpressionStatement: {
        enter({ node, parent }) {
          if (t.isAssignmentExpression(node.expression) && node.expression.operator === '=') {
            const { left, right } = node.expression;
            if (
              t.isMemberExpression(left) &&
              t.isIdentifier(left.object) &&
              left.object.name === 'module' &&
              t.isIdentifier(left.property) &&
              left.property.name === 'exports'
            ) {
              let exportObject = right;
              if (t.isIdentifier(right)) {
                exportObject = _findVarInitialization(right.name, parent as t.Program);
              }
              if (t.isObjectExpression(exportObject)) {
                self._exportsObject = exportObject;
                exportObject.properties.forEach((p: t.ObjectProperty) => {
                  const exportName = propKey(p);
                  if (exportName) {
                    let exportVal = p.value;
                    if (t.isIdentifier(exportVal)) {
                      exportVal = _findVarInitialization(exportVal.name, parent as t.Program);
                    }
                    self._exports[exportName] = exportVal as t.Expression;
                  }
                });
              } else {
                logger.warn(`Unexpected ${JSON.stringify(node)}`);
              }
            }
          }
        },
      },
    });
    return self;
  }