Fix absent() checks

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Changelog
 
+## v0.6.1
+
+### Fixed
+
+- Labels returned by `absent()` are only from equal match types (`absent(foo="bar")`,
+  not `absent(foo=~"bar.+")` but `alerts/template` didn't test for match type when
+  checking for labels sourced from `absent()` queries.
+
 ## v0.6.0
 
 ### Changed

internal/checks/alerts_template.go

@@ -12,6 +12,7 @@ import (
 	"github.com/cloudflare/pint/internal/parser"
 	"github.com/cloudflare/pint/internal/parser/utils"
 	"github.com/prometheus/common/model"
+	"github.com/prometheus/prometheus/model/labels"
 	"github.com/prometheus/prometheus/model/timestamp"
 	promTemplate "github.com/prometheus/prometheus/template"
 )
@@ -345,7 +346,9 @@ func absentLabels(node *parser.PromQLNode) []string {
 	for _, child := range node.Children {
 		for _, v := range utils.HasVectorSelector(child) {
 			for _, lm := range v.LabelMatchers {
-				labelMap[lm.Name] = struct{}{}
+				if lm.Type == labels.MatchEqual {
+					labelMap[lm.Name] = struct{}{}
+				}
 			}
 		}
 	}

internal/checks/alerts_template_test.go

@@ -412,6 +412,25 @@ func TestTemplateCheck(t *testing.T) {
 				},
 			},
 		},
+		{
+			description: "annotation label missing from metrics (absent({job=~}))",
+			content: `
+- alert: Foo Is Missing
+  expr: absent({job=~".+"})
+  annotations:
+    summary: '{{ .Labels.job }} is missing'
+`,
+			checker: checks.NewTemplateCheck(),
+			problems: []checks.Problem{
+				{
+					Fragment: `summary: {{ .Labels.job }} is missing`,
+					Lines:    []int{5},
+					Reporter: "alerts/template",
+					Text:     `template is using "job" label but absent() is not passing it`,
+					Severity: checks.Bug,
+				},
+			},
+		},
 	}
 	runTests(t, testCases)
 }