name : isAsyncOperation.js import {ContextualKeyword} from "../parser/tokenizer/keywords"; /** * Determine whether this optional chain or nullish coalescing operation has any await statements in * it. If so, we'll need to transpile to an async operation. * * We compute this by walking the length of the operation and returning true if we see an await * keyword used as a real await (rather than an object key or property access). Nested optional * chain/nullish operations need to be tracked but don't silence await, but a nested async function * (or any other nested scope) will make the await not count. */ export default function isAsyncOperation(tokens) { let index = tokens.currentIndex(); let depth = 0; const startToken = tokens.currentToken(); do { const token = tokens.tokens[index]; if (token.isOptionalChainStart) { depth++; } if (token.isOptionalChainEnd) { depth--; } depth += token.numNullishCoalesceStarts; depth -= token.numNullishCoalesceEnds; if ( token.contextualKeyword === ContextualKeyword._await && token.identifierRole == null && token.scopeDepth === startToken.scopeDepth ) { return true; } index += 1; } while (depth > 0 && index < tokens.tokens.length); return false; }