sucrase/dist/index.mjs

import CJSImportProcessor from "./CJSImportProcessor";
import computeSourceMap, {} from "./computeSourceMap";
import identifyShadowedGlobals from "./identifyShadowedGlobals";
import NameManager from "./NameManager";
import {parse} from "./parser";

import TokenProcessor from "./TokenProcessor";
import RootTransformer from "./transformers/RootTransformer";
import formatTokens from "./util/formatTokens";
import getTSImportedNames from "./util/getTSImportedNames";

























































export function getVersion() {
  // eslint-disable-next-line
  return require("../package.json").version;
}

export function transform(code, options) {
  try {
    const sucraseContext = getSucraseContext(code, options);
    const transformer = new RootTransformer(
      sucraseContext,
      options.transforms,
      Boolean(options.enableLegacyBabel5ModuleInterop),
      options,
    );
    let result = {code: transformer.transform()};
    if (options.sourceMapOptions) {
      if (!options.filePath) {
        throw new Error("filePath must be specified when generating a source map.");
      }
      result = {
        ...result,
        sourceMap: computeSourceMap(result.code, options.filePath, options.sourceMapOptions),
      };
    }
    return result;
  } catch (e) {
    if (options.filePath) {
      e.message = `Error transforming ${options.filePath}: ${e.message}`;
    }
    throw e;
  }
}

/**
 * Return a string representation of the sucrase tokens, mostly useful for
 * diagnostic purposes.
 */
export function getFormattedTokens(code, options) {
  const tokens = getSucraseContext(code, options).tokenProcessor.tokens;
  return formatTokens(code, tokens);
}

/**
 * Call into the parser/tokenizer and do some further preprocessing:
 * - Come up with a set of used names so that we can assign new names.
 * - Preprocess all import/export statements so we know which globals we are interested in.
 * - Compute situations where any of those globals are shadowed.
 *
 * In the future, some of these preprocessing steps can be skipped based on what actual work is
 * being done.
 */
function getSucraseContext(code, options) {
  const isJSXEnabled = options.transforms.includes("jsx");
  const isTypeScriptEnabled = options.transforms.includes("typescript");
  const isFlowEnabled = options.transforms.includes("flow");
  const file = parse(code, isJSXEnabled, isTypeScriptEnabled, isFlowEnabled);
  const tokens = file.tokens;
  const scopes = file.scopes;

  const tokenProcessor = new TokenProcessor(code, tokens, isFlowEnabled);
  const nameManager = new NameManager(tokenProcessor);
  nameManager.preprocessNames();
  const enableLegacyTypeScriptModuleInterop = Boolean(options.enableLegacyTypeScriptModuleInterop);

  let importProcessor = null;
  if (options.transforms.includes("imports")) {
    importProcessor = new CJSImportProcessor(
      nameManager,
      tokenProcessor,
      enableLegacyTypeScriptModuleInterop,
    );
    importProcessor.preprocessTokens();
    // We need to mark shadowed globals after processing imports so we know that the globals are,
    // but before type-only import pruning, since that relies on shadowing information.
    identifyShadowedGlobals(tokenProcessor, scopes, importProcessor.getGlobalNames());
    if (options.transforms.includes("typescript")) {
      importProcessor.pruneTypeOnlyImports();
    }
  } else if (options.transforms.includes("typescript")) {
    identifyShadowedGlobals(tokenProcessor, scopes, getTSImportedNames(tokenProcessor));
  }
  return {tokenProcessor, scopes, nameManager, importProcessor};
}