Function transformCommonjs

packages/commonjs/src/transform-commonjs.js:46–597

(
  parse,
  code,
  id,
  isEsModule,
  ignoreGlobal,
  ignoreRequire,
  ignoreDynamicRequires,
  getIgnoreTryCatchRequireStatementMode,
  sourceMap,
  isDynamicRequireModulesEnabled,
  dynamicRequireModules,
  commonDir,
  astCache,
  defaultIsModuleExports,
  needsRequireWrapper,
  resolveRequireSourcesAndUpdateMeta,
  isRequired,
  checkDynamicRequire,
  commonjsMeta
)

// - usesRequireWrapper
// - isWrapped
export default async function transformCommonjs(
  parse,
  code,
  id,
  isEsModule,
  ignoreGlobal,
  ignoreRequire,
  ignoreDynamicRequires,
  getIgnoreTryCatchRequireStatementMode,
  sourceMap,
  isDynamicRequireModulesEnabled,
  dynamicRequireModules,
  commonDir,
  astCache,
  defaultIsModuleExports,
  needsRequireWrapper,
  resolveRequireSourcesAndUpdateMeta,
  isRequired,
  checkDynamicRequire,
  commonjsMeta
) {
  const ast = astCache || tryParse(parse, code, id);
  const magicString = new MagicString(code);
  const uses = {
    module: false,
    exports: false,
    global: false,
    require: false
  };
  const virtualDynamicRequirePath =
    isDynamicRequireModulesEnabled && getVirtualPathForDynamicRequirePath(dirname(id), commonDir);
  let scope = attachScopes(ast, 'scope');
  let lexicalDepth = 0;
  let programDepth = 0;
  let classBodyDepth = 0;
  let currentTryBlockEnd = null;
  let shouldWrap = false;

  const globals = new Set();
  // A conditionalNode is a node for which execution is not guaranteed. If such a node is a require
  // or contains nested requires, those should be handled as function calls unless there is an
  // unconditional require elsewhere.
  let currentConditionalNodeEnd = null;
  const conditionalNodes = new Set();
  const { addRequireExpression, rewriteRequireExpressionsAndGetImportBlock } = getRequireHandlers();

  // See which names are assigned to. This is necessary to prevent
  // illegally replacing `var foo = require('foo')` with `import foo from 'foo'`,
  // where `foo` is later reassigned. (This happens in the wild. CommonJS, sigh)
  const reassignedNames = new Set();
  const topLevelDeclarations = [];
  const skippedNodes = new Set();
  const moduleAccessScopes = new Set([scope]);
  const exportsAccessScopes = new Set([scope]);
  const moduleExportsAssignments = [];
  let firstTopLevelModuleExportsAssignment = null;
  const exportsAssignmentsByName = new Map();
  const topLevelAssignments = new Set();