Optimize print calls in spy matches (#5596)

packages/expect/src/spy_matchers.js

@@ -172,15 +172,27 @@ const ensureMock = (mockOrSpy, matcherName) => {
  }
 };
 
+const getPrintedCalls = (
+ calls: any[],
+ limit: number,
+ sep: string,
+ fn: Function,
+): string => {
+ const result = [];
+ let i = calls.length;
+
+ while (--i >= 0 && --limit >= 0) {
+ result.push(fn(calls[i]));
+ }
+
+ return result.join(sep);
+};
+
 const formatReceivedCalls = (calls, limit, options) => {
  if (calls.length) {
  const but = options && options.sameSentence ? 'but' : 'But';
  const count = calls.length - limit;
- const printedCalls = calls
- .slice(-limit)
- .reverse()
- .map(printReceived)
- .join(', ');
+ const printedCalls = getPrintedCalls(calls, limit, ', ', printReceived);
  return (
  `${but} it was ${options && options.isLast ? 'last ' : ''}called ` +
  `with:\n ` +
@@ -196,11 +208,12 @@ const formatReceivedCalls = (calls, limit, options) => {
 
 const formatMismatchedCalls = (calls, expected, limit) => {
  if (calls.length) {
- return calls
- .slice(-limit)
- .reverse()
- .map(formatMismatchedArgs.bind(null, expected))
- .join('\n\n');
+ return getPrintedCalls(
+ calls,
+ limit,
+ '\n\n',
+ formatMismatchedArgs.bind(null, expected),
+ );
  } else {
  return (
  ` ${printExpected(expected)}\n` +