in packages/jest-reporters/src/SummaryReporter.ts [122:163]
private _printSnapshotSummary(
snapshots: SnapshotSummary,
globalConfig: Config.GlobalConfig,
) {
if (
snapshots.added ||
snapshots.filesRemoved ||
snapshots.unchecked ||
snapshots.unmatched ||
snapshots.updated
) {
let updateCommand;
const event = npm_lifecycle_event || '';
const prefix = NPM_EVENTS.has(event) ? '' : 'run ';
const isYarn =
typeof npm_config_user_agent === 'string' &&
npm_config_user_agent.includes('yarn');
const client = isYarn ? 'yarn' : 'npm';
const scriptUsesJest =
typeof npm_lifecycle_script === 'string' &&
npm_lifecycle_script.includes('jest');
if (globalConfig.watch || globalConfig.watchAll) {
updateCommand = 'press `u`';
} else if (event && scriptUsesJest) {
updateCommand = `run \`${`${client} ${prefix}${event}${
isYarn ? '' : ' --'
}`} -u\``;
} else {
updateCommand = 're-run jest with `-u`';
}
const snapshotSummary = getSnapshotSummary(
snapshots,
globalConfig,
updateCommand,
);
snapshotSummary.forEach(this.log);
this.log(''); // print empty line
}
}