Jasmine slow spec reporter

slow_reporter.js

// A custom Jasmine reporter that logs slow specs.
                                                                        
const warnThresholdMs = 300;
const slowSpecsToPrint = 10;
                                                                        
function now() {
  return (new Date()).getTime();
}
                                                                        
const slowReporter = {
  jasmineStarted() {
    this._specTimes = [];
  },
                                                                        
  specStarted() {
    this._specStartedTime = now();
  },
                                                                        
  specDone(result) {
    const time = now() - this._specStartedTime;
                                                                        
    this._specTimes.push({ fullName: result.fullName, time: time });
    if (time >= warnThresholdMs) {
      console.warn(`${result.fullName} took ${time}ms`);
    }
  },
                                                                        
  jasmineDone() {
    // Print out top slow specs in order
    const slowestSpecs = this._specTimes.sort((a, b) => b.time - a.time)
      .slice(0, slowSpecsToPrint);
                                                                        
    console.log(`${slowSpecsToPrint} slowest specs:`);
    console.table(slowestSpecs);
  },
};
                                                                        
jasmine.getEnv().addReporter(slowReporter);