From 2216361c59e9e4863fb83b903a6fc14893c16e67 Mon Sep 17 00:00:00 2001
From: ah8ad3 <ah8ad3@gmail.com>
Date: Mon, 29 Jan 2024 19:27:27 +0330
Subject: [PATCH] fixes kubectl explain to shows enum for field types if they
 were defined

---
 .../pkg/explain/v2/templates/plaintext.tmpl   | 27 ++++++++++-
 .../explain/v2/templates/plaintext_test.go    | 46 +++++++++++++++++++
 2 files changed, 71 insertions(+), 2 deletions(-)

diff --git a/staging/src/k8s.io/kubectl/pkg/explain/v2/templates/plaintext.tmpl b/staging/src/k8s.io/kubectl/pkg/explain/v2/templates/plaintext.tmpl
index 6cf6c3779ff..3b3d40ba05c 100644
--- a/staging/src/k8s.io/kubectl/pkg/explain/v2/templates/plaintext.tmpl
+++ b/staging/src/k8s.io/kubectl/pkg/explain/v2/templates/plaintext.tmpl
@@ -109,7 +109,7 @@ Takes dictionary as argument with keys:
         {{- $subschema := index $resolved.properties (first $.FieldPath) -}}
         {{- if eq 1 (len $.FieldPath) -}}
             {{- /* TODO: The original explain would say RESOURCE instead of FIELD here under some circumstances */ -}}
-            FIELD: {{first $.FieldPath}} <{{ template "typeGuess" (dict "schema" $subschema "Document" $.Document) }}>{{"\n"}}
+            FIELD: {{first $.FieldPath}} <{{ template "typeGuess" (dict "schema" $subschema "Document" $.Document) }}>{{ template "extractEnum" (dict "schema" $subschema "Document" $.Document) }}{{"\n"}}
             {{- "\n" -}}
         {{- end -}}
         {{- template "output" (set $nextContext "history" (dict) "FieldPath" (slice $.FieldPath 1) "schema" $subschema ) -}}
@@ -201,7 +201,7 @@ Takes dictionary as argument with keys:
     {{- $level := or $.level 0 -}}
     {{- $indentAmount := mul $level 2 -}}
     {{- $fieldSchema := index $.schema.properties $.name -}}
-    {{- $.name | indent $indentAmount -}}{{"\t"}}<{{ template "typeGuess" (dict "schema" $fieldSchema "Document" $.Document) }}>
+    {{- $.name | indent $indentAmount -}}{{"\t"}}<{{ template "typeGuess" (dict "schema" $fieldSchema "Document" $.Document) }}>{{ template "extractEnum" (dict "schema" $fieldSchema "Document" $.Document) }}
     {{- if contains $.schema.required $.name}} -required-{{- end -}}
     {{- "\n" -}}
     {{- if not $.short -}}
@@ -280,4 +280,27 @@ Takes dictionary as argument with keys:
     {{- else -}}
         {{- fail "expected schema argument to subtemplate 'typeguess'" -}}
     {{- end -}}
+{{- end -}}
+
+{{- /* Check if there is any enum returns it in this format e.g.:
+
+        (enum: !=, =, =~, !~)
+
+    Can change the style of enum in future by modifying this function
+
+Takes dictionary as argument with keys:
+    schema: openapiv3 JSON schema
+    Document: openapi document
+*/ -}}
+{{- define "extractEnum" -}}
+    {{- with $.schema -}}
+        {{- if .enum -}}
+            {{- " (enum: " -}}
+            {{- range $index, $element := .enum -}}
+                {{- if gt $index 0 -}} {{- ", " -}} {{- end -}}
+                {{- $element -}}
+            {{- end -}}
+            {{- ")" -}}
+        {{- end -}}
+    {{- end -}}
 {{- end -}}
\ No newline at end of file
diff --git a/staging/src/k8s.io/kubectl/pkg/explain/v2/templates/plaintext_test.go b/staging/src/k8s.io/kubectl/pkg/explain/v2/templates/plaintext_test.go
index 0057164e5f1..83758919142 100644
--- a/staging/src/k8s.io/kubectl/pkg/explain/v2/templates/plaintext_test.go
+++ b/staging/src/k8s.io/kubectl/pkg/explain/v2/templates/plaintext_test.go
@@ -648,6 +648,51 @@ func TestPlaintext(t *testing.T) {
 				checkEquals("          thefield\t<string> -required-\n"),
 			},
 		},
+		{
+			// show that extractEnum can skip empty enum slice
+			Name:        "Enum",
+			Subtemplate: "extractEnum",
+			Context: map[string]any{
+				"schema": map[string]any{
+					"type":        "string",
+					"description": "a description that should not be printed",
+					"enum": []string{},
+				},
+			},
+			Checks: []check{
+				checkEquals(""),
+			},
+		},
+		{
+			// show that extractEnum can extract string enum and style it
+			Name:        "Enum",
+			Subtemplate: "extractEnum",
+			Context: map[string]any{
+				"schema": map[string]any{
+					"type":        "string",
+					"description": "a description that should not be printed",
+					"enum": []string{"!=", "!", "=="},
+				},
+			},
+			Checks: []check{
+				checkEquals(" (enum: !=, !, ==)"),
+			},
+		},
+		{
+			// show that extractEnum can extract integer enum and style it
+			Name:        "Enum",
+			Subtemplate: "extractEnum",
+			Context: map[string]any{
+				"schema": map[string]any{
+					"type":        "string",
+					"description": "a description that should not be printed",
+					"enum": []int{1, 2, 3},
+				},
+			},
+			Checks: []check{
+				checkEquals(" (enum: 1, 2, 3)"),
+			},
+		},
 	}
 
 	tmpl, err := v2.WithBuiltinTemplateFuncs(template.New("")).Parse(plaintextSource)
@@ -668,6 +713,7 @@ func TestPlaintext(t *testing.T) {
 			} else {
 				outputErr = tmpl.ExecuteTemplate(buf, tcase.Subtemplate, tcase.Context)
 			}
+			fmt.Println(outputErr)
 
 			output := buf.String()
 			for _, check := range tcase.Checks {