function getImportedReactName()

in packages/flow-upgrade/src/codemods/ReactUtils.js [30:77]

• 37 lines of code
• 9 McCabe index (conditional complexity)

  function getImportedReactName(path: any): ?string {
    // All of the modules we want to treat as React.
    const REACT_MODULES = new Set(['react', 'React']);
    // Find the first require for React that does not destructure React but
    // instead gives it a name.
    const reactRequire = path
      .findVariableDeclarators()
      .filter(
        j.filters.VariableDeclarator.requiresModule(Array.from(REACT_MODULES)),
      )
      .nodes()
      .find(node => node.id && node.id.type === 'Identifier');
    // If we found a require for React then return the name.
    if (reactRequire) {
      return reactRequire.id.name;
    }
    // Get all of the import declarations that import React.
    const reactImports = path
      .find(j.ImportDeclaration, {
        type: 'ImportDeclaration',
        source: {
          type: 'Literal',
          value: value => REACT_MODULES.has(value),
        },
      })
      .nodes();
    // For all of the React imports...
    for (let i = 0; i < reactImports.length; i++) {
      const reactImport = reactImports[i];
      // ...and for all of each import's specifiers...
      for (let j = 0; j < reactImport.specifiers.length; j++) {
        const specifier = reactImport.specifiers[j];
        // ...check to see if it is either a default specifier or a namespace
        // specifier. If it is either and it has a local name then return that
        // local name.
        if (
          (specifier.type === 'ImportDefaultSpecifier' ||
            specifier.type === 'ImportNamespaceSpecifier') &&
          specifier.local &&
          specifier.local.type === 'Identifier'
        ) {
          return specifier.local.name;
        }
      }
    }
    // Otherwise we can't find anything and should return null.
    return null;
  }