Function emitImport

transforms/react-to-react-dom.js:355–385

(name, path, knownProperties, uses)

      }

      function emitImport(name, path, knownProperties, uses) {
        const usedProperties = coreImportDeclaration.value.specifiers.filter(
          sp => sp.type === j.ImportSpecifier.name
        ).filter(sp =>
          sp.imported.type === 'Identifier' && knownProperties.indexOf(sp.imported.name) !== -1
        ).map(sp => sp.imported.name);

        const importDeclaration = findImportPath(name, path);
        const specifiers = [];

        // if ReactDOM needs to be in scope and it's not declared, or we're going to
        // replace its declaration to add import specifiers...
        if (uses > 0 && (!domAlreadyDeclared || importDeclaration.length > 0)) {
          specifiers.push(j.importDefaultSpecifier(j.identifier(name)));
        }
        if (usedProperties.length > 0) {
          j(coreImportDeclaration).find(j.ImportSpecifier)
            .filter(p => usedProperties.indexOf(p.value.local.name) !== -1)
            .remove();
          specifiers.push(...usedProperties.map(prop =>
            j.importSpecifier(j.identifier(prop))
          ));
        }
        if (specifiers.length > 0) {
          if (importDeclaration.length > 0) {
            importDeclaration.replaceWith(j.importDeclaration(specifiers, j.literal(path)));
          } else {
            coreImportDeclaration.insertAfter(j.importDeclaration(specifiers, j.literal(path)));
          }
        }
      }

      emitImport('ReactDOM', domModuleName, DOM_PROPERTIES, domUses);
      emitImport('ReactDOMServer', domServerModuleName, DOM_SERVER_PROPERTIES, domServerUses);