no-return-promise-resolve.js

module.exports = {
  meta: {
    type: "suggestion",
    fixable: "code",
    schema: [],
    messages: {
      returnResolve: `Values must be returned directly from async functions`,
      returnReject: `Errors must be thrown directly from async functions`,
    },
  },

  create(context, _options) {
    return {
      [`:matches(:function[async=true] ReturnStatement, ArrowFunctionExpression[async=true]) > CallExpression > MemberExpression[object.name="Promise"][property.name=/^(resolve|reject)$/].callee`]:
        (node) => {
          // The AST selector ensures that we are somewhere within an async function, but we might
          // be in a nested function that is not async. Check that the innermost function scope is
          // actually async.
          const functionScope = context.getScope().variableScope;
          if (functionScope.type !== "function" || !functionScope.block.async) {
            return;
          }
          const sourceCode = context.getSourceCode();
          const returnOrArrowFunction = node.parent.parent;
          const callExpr = node.parent;
          const isReturn = returnOrArrowFunction.type === "ReturnStatement";
          const isArrowFunction = !isReturn;
          const isReject = node.property.name === "reject";
          context.report({
            node: isReject && isReturn ? returnOrArrowFunction : callExpr,
            messageId: isReject ? "returnReject" : "returnResolve",
            fix(fixer) {
              if (callExpr.arguments.length === 0) {
                return fixer.replaceText(callExpr, "undefined");
              }
              if (isReject) {
                if (isArrowFunction) {
                  return fixer.replaceText(
                    returnOrArrowFunction.body,
                    `{ throw ${sourceCode.getText(callExpr.arguments[0])}; }`
                  );
                } else {
                  return fixer.replaceText(
                    returnOrArrowFunction,
                    `throw ${sourceCode.getText(callExpr.arguments[0])};`
                  );
                }
              }
              const firstArgToken = sourceCode.getFirstToken(
                callExpr.arguments[0]
              );
              const needsParens =
                isArrowFunction &&
                firstArgToken.type === "Punctuator" &&
                firstArgToken.value === "{";
              const argText = sourceCode.getText(callExpr.arguments[0]);
              return fixer.replaceText(
                callExpr,
                needsParens ? `(${argText})` : argText
              );
            },
          });
        },
    };
  },
};