feat: Add experimental filters to trigger describe cmd (#1794)

* feat: Add cesql filter field to trigger describe cmd

* Refactor trigger describe based on defined fields in filter

* Fix comment typo

* Refactor without reflection

pkg/kn/commands/trigger/describe.go

@@ -19,7 +19,6 @@ import (
 
 	"github.com/spf13/cobra"
 	"k8s.io/cli-runtime/pkg/genericclioptions"
-
 	"knative.dev/client/lib/printing"
 	"knative.dev/client/pkg/kn/commands"
 	"knative.dev/client/pkg/printers"
@@ -123,4 +122,65 @@ func writeTrigger(dw printers.PrefixWriter, trigger *v1beta1.Trigger, printDetai
 			subWriter.WriteAttribute(key, value)
 		}
 	}
+	if len(trigger.Spec.Filters) > 0 {
+		// Split 'Filter' and 'Filters (experimental)' with new line
+		dw.WriteLine()
+		subWriter := dw.WriteAttribute("Filters (experimental)", "")
+		for _, filter := range trigger.Spec.Filters {
+			writeNestedFilters(subWriter, filter)
+		}
+	}
+}
+
+// writeNestedFilters goes through SubscriptionsAPIFilter and writes its content accordingly
+func writeNestedFilters(dw printers.PrefixWriter, filter v1beta1.SubscriptionsAPIFilter) {
+	// All []SubscriptionsAPIFilter
+	if len(filter.All) > 0 {
+		// create new indentation after name
+		subWriter := dw.WriteAttribute("all", "")
+		for _, nestedFilter := range filter.All {
+			writeNestedFilters(subWriter, nestedFilter)
+		}
+	}
+	// Any []SubscriptionsAPIFilter
+	if len(filter.Any) > 0 {
+		// create new indentation after name
+		subWriter := dw.WriteAttribute("any", "")
+		for _, nestedFilter := range filter.Any {
+			writeNestedFilters(subWriter, nestedFilter)
+		}
+	}
+	// Not *SubscriptionsAPIFilter
+	if filter.Not != nil {
+		subWriter := dw.WriteAttribute("not", "")
+		writeNestedFilters(subWriter, *filter.Not)
+	}
+	// Exact map[string]string
+	if len(filter.Exact) > 0 {
+		// create new indentation after name
+		subWriter := dw.WriteAttribute("exact", "")
+		for k, v := range filter.Exact {
+			subWriter.WriteAttribute(k, v)
+		}
+	}
+	// Prefix map[string]string
+	if len(filter.Prefix) > 0 {
+		// create new indentation after name
+		subWriter := dw.WriteAttribute("prefix", "")
+		for k, v := range filter.Prefix {
+			subWriter.WriteAttribute(k, v)
+		}
+	}
+	// Suffix map[string]string
+	if len(filter.Suffix) > 0 {
+		// create new indentation after name
+		subWriter := dw.WriteAttribute("suffix", "")
+		for k, v := range filter.Suffix {
+			subWriter.WriteAttribute(k, v)
+		}
+	}
+	// CESQL string
+	if filter.CESQL != "" {
+		dw.WriteAttribute("cesql", filter.CESQL)
+	}
 }

pkg/kn/commands/trigger/describe_test.go

@@ -15,10 +15,13 @@
 package trigger
 
 import (
+	"bytes"
 	"encoding/json"
 	"errors"
 	"testing"
 
+	"knative.dev/client/pkg/printers"
+
 	"gotest.tools/v3/assert"
 	"gotest.tools/v3/assert/cmp"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -48,6 +51,7 @@ func TestSimpleDescribe(t *testing.T) {
 
 		assert.Assert(t, util.ContainsAll(out, "Broker:", "mybroker"))
 		assert.Assert(t, util.ContainsAll(out, "Filter:", "type", "foo.type.knative", "source", "src.eventing.knative"))
+		assert.Assert(t, util.ContainsAll(out, "Filters", "experimental", "cesql", "LOWER", "type"))
 		assert.Assert(t, util.ContainsAll(out, "Sink:", "Service", "myservicenamespace", "mysvc"))
 	})
 
@@ -112,6 +116,158 @@ func TestDescribeTriggerMachineReadable(t *testing.T) {
 	recorder.Validate()
 }
 
+func TestWriteNestedFilters(t *testing.T) {
+	testCases := []struct {
+		name           string
+		filter         v1beta1.SubscriptionsAPIFilter
+		expectedOutput string
+	}{
+		{
+			name: "Exact filter",
+			filter: v1beta1.SubscriptionsAPIFilter{
+				Exact: map[string]string{
+					"type": "example"}},
+			expectedOutput: "exact:   \n" +
+				"  type:  example\n",
+		},
+		{
+			name: "Prefix filter",
+			filter: v1beta1.SubscriptionsAPIFilter{
+				Prefix: map[string]string{
+					"type": "foo.bar"}},
+			expectedOutput: "" +
+				"prefix:  \n" +
+				"  type:  foo.bar\n",
+		},
+		{
+			name: "Suffix filter",
+			filter: v1beta1.SubscriptionsAPIFilter{
+				Suffix: map[string]string{
+					"type": "foo.bar"}},
+			expectedOutput: "" +
+				"suffix:  \n" +
+				"  type:  foo.bar\n",
+		},
+		{
+			name: "All filter",
+			filter: v1beta1.SubscriptionsAPIFilter{
+				All: []v1beta1.SubscriptionsAPIFilter{
+					{Exact: map[string]string{
+						"type": "foo.bar"}},
+					{Prefix: map[string]string{
+						"source": "foo"}},
+					{Suffix: map[string]string{
+						"subject": "test"}}}},
+			expectedOutput: "" +
+				"all:          \n" +
+				"  exact:      \n" +
+				"    type:     foo.bar\n" +
+				"  prefix:     \n" +
+				"    source:   foo\n" +
+				"  suffix:     \n" +
+				"    subject:  test\n",
+		},
+		{
+			name: "Any filter",
+			filter: v1beta1.SubscriptionsAPIFilter{
+				Any: []v1beta1.SubscriptionsAPIFilter{
+					{Exact: map[string]string{
+						"type": "foo.bar"}},
+					{Prefix: map[string]string{
+						"source": "foo"}},
+					{Suffix: map[string]string{
+						"subject": "test"}}},
+			},
+			expectedOutput: "" +
+				"any:          \n" +
+				"  exact:      \n" +
+				"    type:     foo.bar\n" +
+				"  prefix:     \n" +
+				"    source:   foo\n" +
+				"  suffix:     \n" +
+				"    subject:  test\n",
+		},
+		{
+			name: "Nested All filter",
+			filter: v1beta1.SubscriptionsAPIFilter{
+				All: []v1beta1.SubscriptionsAPIFilter{
+					{Exact: map[string]string{
+						"type": "foo.bar"}},
+					{All: []v1beta1.SubscriptionsAPIFilter{
+						{Prefix: map[string]string{
+							"source": "foo"}},
+						{Suffix: map[string]string{
+							"subject": "test"}}}}}},
+			expectedOutput: "" +
+				"all:            \n" +
+				"  exact:        \n" +
+				"    type:       foo.bar\n" +
+				"  all:          \n" +
+				"    prefix:     \n" +
+				"      source:   foo\n" +
+				"    suffix:     \n" +
+				"      subject:  test\n",
+		},
+		{
+			name: "Nested Any filter",
+			filter: v1beta1.SubscriptionsAPIFilter{
+				Any: []v1beta1.SubscriptionsAPIFilter{
+					{Exact: map[string]string{
+						"type": "foo.bar"}},
+					{Any: []v1beta1.SubscriptionsAPIFilter{
+						{Prefix: map[string]string{
+							"source": "foo"}},
+						{Suffix: map[string]string{
+							"subject": "test"}}}}}},
+			expectedOutput: "" +
+				"any:            \n" +
+				"  exact:        \n" +
+				"    type:       foo.bar\n" +
+				"  any:          \n" +
+				"    prefix:     \n" +
+				"      source:   foo\n" +
+				"    suffix:     \n" +
+				"      subject:  test\n",
+		},
+		{
+			name: "Nested Not filter",
+			filter: v1beta1.SubscriptionsAPIFilter{
+				Not: &v1beta1.SubscriptionsAPIFilter{
+					Exact: map[string]string{
+						"type": "foo.bar",
+					},
+					Prefix: map[string]string{
+						"type": "bar",
+					},
+					CESQL: "select bar",
+					Not: &v1beta1.SubscriptionsAPIFilter{
+						Suffix: map[string]string{
+							"source": "foo"}}}},
+			expectedOutput: "" +
+				"not:           \n" +
+				"  not:         \n" +
+				"    suffix:    \n" +
+				"      source:  foo\n" +
+				"  exact:       \n" +
+				"    type:      foo.bar\n" +
+				"  prefix:      \n" +
+				"    type:      bar\n" +
+				"  cesql:       select bar\n",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			buf := &bytes.Buffer{}
+			dw := printers.NewPrefixWriter(buf)
+			writeNestedFilters(dw, tc.filter)
+			err := dw.Flush()
+			assert.NilError(t, err)
+			assert.Equal(t, tc.expectedOutput, buf.String())
+		})
+	}
+}
+
 func getTriggerSinkRef() *v1beta1.Trigger {
 	return &v1beta1.Trigger{
 		TypeMeta: v1.TypeMeta{
@@ -130,6 +286,9 @@ func getTriggerSinkRef() *v1beta1.Trigger {
 					"source": "src.eventing.knative",
 				},
 			},
+			Filters: []v1beta1.SubscriptionsAPIFilter{
+				{CESQL: "LOWER(type) = 'my-event-type'"},
+			},
 			Subscriber: duckv1.Destination{
 				Ref: &duckv1.KReference{
 					Kind:      "Service",