Add helper functions for linting to testutil

Signed-off-by: beorn7 <beorn@grafana.com>
This commit is contained in:
beorn7 2020-04-24 23:44:21 +02:00
parent 6433bcf819
commit 39dbb24d13
3 changed files with 120 additions and 0 deletions

View File

@ -0,0 +1,46 @@
// Copyright 2020 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package testutil
import (
"fmt"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/testutil/promlint"
)
// CollectAndLint registers the provided Collector with a newly created
// pedantic Registry. It then does the same as GatherAndLint, gathering the
// metrics from the pedantic Registry.
func CollectAndLint(c prometheus.Collector, metricNames ...string) ([]promlint.Problem, error) {
reg := prometheus.NewPedanticRegistry()
if err := reg.Register(c); err != nil {
return nil, fmt.Errorf("registering collector failed: %s", err)
}
return GatherAndLint(reg, metricNames...)
}
// GatherAndLint gathers all metrics from the provided Gatherer and checks them
// with the linter in the promlint package. If any metricNames are provided,
// only metrics with those names are checked.
func GatherAndLint(g prometheus.Gatherer, metricNames ...string) ([]promlint.Problem, error) {
got, err := g.Gather()
if err != nil {
return nil, fmt.Errorf("gathering metrics failed: %s", err)
}
if metricNames != nil {
got = filterMetrics(got, metricNames)
}
return promlint.NewWithMetricFamilies(got).Lint()
}

View File

@ -0,0 +1,70 @@
// Copyright 2020 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package testutil
import (
"testing"
"github.com/prometheus/client_golang/prometheus"
)
func TestCollectAndLintGood(t *testing.T) {
cnt := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "some_total",
Help: "A value that represents a counter.",
ConstLabels: prometheus.Labels{
"label1": "value1",
},
},
[]string{"foo"},
)
cnt.WithLabelValues("bar")
cnt.WithLabelValues("baz")
problems, err := CollectAndLint(cnt)
if err != nil {
t.Error("Unexpected error:", err)
}
if len(problems) > 0 {
t.Error("Unexpected lint problems:", problems)
}
}
func TestCollectAndLintBad(t *testing.T) {
cnt := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "someThing_ms",
Help: "A value that represents a counter.",
ConstLabels: prometheus.Labels{
"label1": "value1",
},
},
[]string{"fooBar"},
)
cnt.WithLabelValues("bar")
cnt.WithLabelValues("baz")
problems, err := CollectAndLint(cnt)
if err != nil {
t.Error("Unexpected error:", err)
}
if len(problems) < 5 {
// The exact nature of the lint problems found is tested within
// the promlint package itself. Here we only want to make sure
// that the collector successfully hit the linter and got enough
// problems flagged.
t.Error("Not enough lint problems found.")
}
}

View File

@ -31,6 +31,10 @@
// testing custom prometheus.Collector implementations and in particular whole
// exporters, i.e. programs that retrieve telemetry data from a 3rd party source
// and convert it into Prometheus metrics.
//
// In a similar pattern, CollectAndLint and GatherAndLint can be used to detect
// metrics that have issues with their name, type, or metadata without being
// necessarily invalid, e.g. a counter with a name missing the “_total” suffix.
package testutil
import (