fxa-auth-server mock statsd lacks of function histogram

[jackyzy823]

Description

Here

fxa/packages/fxa-shared/db/redis.ts

Line 210 in 4dfbfbc

this.metrics?.histogram(

requires metrics is not null and metrics.histogram is a function

If metrics is not enabled, mock Statsd will be used:

fxa/packages/fxa-auth-server/bin/key_server.js

Lines 43 to 55 in 4dfbfbc

	const statsd = config.statsd.enabled
	? new StatsD({
	...config.statsd,
	errorHandler: (err) => {
	// eslint-disable-next-line no-use-before-define
	log.error('statsd.error', err);
	},
	})
	: {
	increment: () => {},
	timing: () => {},
	close: () => {},
	};

However it lacks of function histogram

metrics is initialized here :

fxa/packages/fxa-auth-server/lib/redis.js

Lines 19 to 23 in 4dfbfbc

	function resolveMetrics() {
	if (Container.has(StatsD)) {
	return Container.get(StatsD);
	}
	}

Solution:

1. Either set metrics to undefined if metrics is not enabled, like here
   

   fxa/packages/fxa-graphql-api/src/scripts/must-change-password.ts

   Lines 38 to 46 in 4dfbfbc

   	const metrics = config.metrics?.host
   	? new StatsD({
   	...config.metrics,
   	errorHandler: (err) => {
   	// eslint-disable-next-line no-use-before-define
   	logger.error('statsd.error', { err });
   	},
   	})
   	: undefined;

2. Or mock histogram function (and possibly other functions)

┆Issue is synchronized with this Jira Task