Add linter to check if api docs match field tag names

cmd/fieldnamedocscheck/field_name_docs_check.go

@@ -0,0 +1,105 @@
+/*
+Copyright 2023 The Kubernetes 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 main
+
+import (
+	"fmt"
+	"os"
+	"regexp"
+	"strings"
+
+	flag "github.com/spf13/pflag"
+	kruntime "k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/klog/v2"
+)
+
+var (
+	typeSrc = flag.StringP("type-src", "s", "", "From where we are going to read the types")
+	re      = regexp.MustCompile("`(\\b\\w+\\b)`")
+)
+
+// kubeTypesMap is a map from field name to its tag name and doc.
+type kubeTypesMap map[string]kruntime.Pair
+
+func main() {
+	flag.Parse()
+
+	if *typeSrc == "" {
+		klog.Fatalf("Please define -s flag as it is the api type file")
+	}
+
+	docsForTypes := kruntime.ParseDocumentationFrom(*typeSrc)
+	rc := false
+
+	for _, ks := range docsForTypes {
+		typesMap := make(kubeTypesMap)
+
+		for _, p := range ks[1:] {
+			// skip the field with no tag name
+			if p.Name != "" {
+				typesMap[strings.ToLower(p.Name)] = p
+			}
+		}
+
+		structName := ks[0].Name
+
+		rc = checkFieldNameAndDoc(structName, "", ks[0].Doc, typesMap)
+		for _, p := range ks[1:] {
+			rc = checkFieldNameAndDoc(structName, p.Name, p.Doc, typesMap)
+		}
+	}
+
+	if rc {
+		os.Exit(1)
+	}
+}
+
+func checkFieldNameAndDoc(structName, fieldName, doc string, typesMap kubeTypesMap) bool {
+	rc := false
+	visited := sets.Set[string]{}
+
+	// The rule is:
+	// 1. Get all back-tick quoted names in the doc
+	// 2. Skip the name which is already found mismatched.
+	// 3. Skip the name whose lowercase is different from the lowercase of tag names,
+	//    because some docs use back-tick to quote field value or nil
+	// 4. Check if the name is different from its tag name
+
+	// TODO: a manual pass adding back-ticks to the doc strings, then update the linter to
+	// check the existence of back-ticks
+	nameGroups := re.FindAllStringSubmatch(doc, -1)
+	for _, nameGroup := range nameGroups {
+		name := nameGroup[1]
+		if visited.Has(name) {
+			continue
+		}
+		if p, ok := typesMap[strings.ToLower(name)]; ok && p.Name != name {
+			rc = true
+			visited.Insert(name)
+
+			fmt.Fprintf(os.Stderr, "Error: doc for %s", structName)
+			if fieldName != "" {
+				fmt.Fprintf(os.Stderr, ".%s", fieldName)
+			}
+
+			fmt.Fprintf(os.Stderr, " contains: %s, which should be: %s\n", name, p.Name)
+		}
+	}
+
+	return rc
+}