Add more tests

internal/checks/base_test.go

@@ -76,6 +76,25 @@ func simpleProm(name, uri string, timeout time.Duration, required bool) *promapi
 	)
 }
 
+func doubleProm(name, uri string, timeout time.Duration, required bool) *promapi.FailoverGroup {
+	return promapi.NewFailoverGroup(
+		name,
+		[]*promapi.Prometheus{
+			promapi.NewPrometheus(name, uri, map[string]string{"X-Debug": "1"}, timeout, 16, 1000, nil),
+			promapi.NewPrometheus(name+"2", uri, map[string]string{"X-Debug": "1"}, timeout, 16, 1000, nil),
+		},
+		required,
+		"up",
+		nil,
+		nil,
+		nil,
+	)
+}
+
+func newDoubleProm(uri string) *promapi.FailoverGroup {
+	return doubleProm("prom", uri, time.Second*5, true)
+}
+
 func newSimpleProm(uri string) *promapi.FailoverGroup {
 	return simpleProm("prom", uri, time.Second*5, true)
 }

internal/checks/promql_counter_test.go

@@ -11,6 +11,30 @@ import (
 	"github.com/cloudflare/pint/internal/promapi"
 )
 
+var (
+	respondWithInternalErrorThenGoodData func(writer responseWriter) responseWriter
+	respondWithEmptyDataThenGoodData     func(writer responseWriter) responseWriter
+)
+
+func init() {
+	respondWithInternalErrorThenGoodDataState := 0
+	respondWithInternalErrorThenGoodData = func(goodResponse responseWriter) responseWriter {
+		respondWithInternalErrorThenGoodDataState++
+		if respondWithInternalErrorThenGoodDataState == 0 {
+			return promError{code: 500, errorType: v1.ErrServer, err: "internal error"}
+		}
+		return goodResponse
+	}
+	respondWithEmptyDataThenGoodDataState := 0
+	respondWithEmptyDataThenGoodData = func(goodResponse responseWriter) responseWriter {
+		respondWithEmptyDataThenGoodDataState++
+		if respondWithEmptyDataThenGoodDataState == 0 {
+			return metadataResponse{metadata: map[string][]v1.Metadata{}}
+		}
+		return goodResponse
+	}
+}
+
 func newCounterCheck(prom *promapi.FailoverGroup) checks.RuleChecker {
 	return checks.NewCounterCheck(prom)
 }
@@ -202,6 +226,19 @@ func TestCounterCheck(t *testing.T) {
 				},
 			},
 		},
+		{
+			description: "empty data from Prometheus API",
+			content:     "- alert: my alert\n  expr: irate(foo[5m])\n",
+			checker:     newCounterCheck,
+			prometheus:  newSimpleProm,
+			problems:    noProblems,
+			mocks: []*prometheusMock{
+				{
+					conds: []requestCondition{requireMetadataPath},
+					resp:  metadataResponse{metadata: map[string][]v1.Metadata{}},
+				},
+			},
+		},
 		{
 			description: "500 error from Prometheus API",
 			content:     "- record: foo\n  expr: rate(foo[5m])\n",
@@ -225,6 +262,48 @@ func TestCounterCheck(t *testing.T) {
 				},
 			},
 		},
+		{
+			description: "500 error from first Prometheus API - use counter with rate",
+			content:     "- record: foo\n  expr: rate(foo[5m])\n",
+			checker:     newCounterCheck,
+			prometheus:  newDoubleProm,
+			problems:    noProblems,
+
+			mocks: []*prometheusMock{
+				{
+					conds: []requestCondition{requireMetadataPath},
+					resp: respondWithInternalErrorThenGoodData(metadataResponse{metadata: map[string][]v1.Metadata{
+						"foo": {{Type: "counter"}},
+					}}),
+				},
+			},
+		},
+		{
+			description: "empty data from first Prometheus API - use counter with delta",
+			content:     "- record: foo\n  expr: delta(foo[5m])\n",
+			checker:     newCounterCheck,
+			prometheus:  newDoubleProm,
+			problems: func(uri string) []checks.Problem {
+				return []checks.Problem{
+					{
+						Fragment: "foo",
+						Lines:    []int{2},
+						Reporter: "promql/counter",
+						Text:     CounterMustUseFuncTextForRecordingRule("foo"),
+						Severity: checks.Warning,
+					},
+				}
+			},
+
+			mocks: []*prometheusMock{
+				{
+					conds: []requestCondition{requireMetadataPath},
+					resp: respondWithEmptyDataThenGoodData(metadataResponse{metadata: map[string][]v1.Metadata{
+						"foo": {{Type: "counter"}},
+					}}),
+				},
+			},
+		},
 	}
 
 	runTests(t, testCases)