swagger type documentation generator

pkg/runtime/swagger_doc_generator.go

@@ -0,0 +1,228 @@
+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+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 runtime
+
+import (
+	"bytes"
+	"fmt"
+	"go/ast"
+	"go/doc"
+	"go/parser"
+	"go/token"
+	"io"
+	"reflect"
+	"strings"
+)
+
+// Pair of strings. We keed the name of fields and the doc
+type Pair struct {
+	Name, Doc string
+}
+
+// KubeTypes is an array to represent all available types in a parsed file. [0] is for the type itself
+type KubeTypes []Pair
+
+func astFrom(filePath string) *doc.Package {
+	fset := token.NewFileSet()
+	m := make(map[string]*ast.File)
+
+	f, err := parser.ParseFile(fset, filePath, nil, parser.ParseComments)
+	if err != nil {
+		fmt.Println(err)
+		return nil
+	}
+
+	m[filePath] = f
+	apkg, _ := ast.NewPackage(fset, m, nil, nil)
+
+	return doc.New(apkg, "", 0)
+}
+
+func fmtRawDoc(rawDoc string) string {
+	var buffer bytes.Buffer
+	delPrevChar := func() {
+		if buffer.Len() > 0 {
+			buffer.Truncate(buffer.Len() - 1) // Delete the last " " or "\n"
+		}
+	}
+
+	// Ignore all lines after ---
+	rawDoc = strings.Split(rawDoc, "---")[0]
+
+	for _, line := range strings.Split(rawDoc, "\n") {
+		line = strings.TrimRight(line, " ")
+
+		if line == "" { // Keep paragraphs
+			delPrevChar()
+			buffer.WriteString("\n\n")
+		} else if !strings.HasPrefix(strings.TrimLeft(line, " "), "TODO") { // Ignore one line TODOs
+			if strings.HasPrefix(line, " ") || strings.HasPrefix(line, "\t") {
+				delPrevChar()
+				line = "\n" + line + "\n" // Replace it with newline. This is useful when we have a line with: "Example:\n\tJSON-someting..."
+			} else {
+				line += " "
+			}
+			buffer.WriteString(line)
+		}
+	}
+
+	postDoc := strings.TrimRight(buffer.String(), "\n")
+	postDoc = strings.Replace(postDoc, "\\\"", "\"", -1) // replace user's \" to "
+	postDoc = strings.Replace(postDoc, "\"", "\\\"", -1) // Escape "
+	postDoc = strings.Replace(postDoc, "\n", "\\n", -1)
+	postDoc = strings.Replace(postDoc, "\t", "\\t", -1)
+
+	return postDoc
+}
+
+// fieldName returns the name of the field as it should appear in JSON format
+// "-" indicates that this field is not part of the JSON representation
+func fieldName(field *ast.Field) string {
+	jsonTag := ""
+	if field.Tag != nil {
+		jsonTag = reflect.StructTag(field.Tag.Value[1 : len(field.Tag.Value)-1]).Get("json") // Delete first and last quotation
+		if strings.Contains(jsonTag, "inline") {
+			return "-"
+		}
+	}
+
+	jsonTag = strings.Split(jsonTag, ",")[0] // This can return "-"
+	if jsonTag == "" {
+		if field.Names != nil {
+			return field.Names[0].Name
+		}
+		return field.Type.(*ast.Ident).Name
+	}
+	return jsonTag
+}
+
+func writeFuncHeader(b *buffer, structName string, indent int) {
+	s := fmt.Sprintf("var map_%s = map[string]string {\n", structName)
+	b.addLine(s, indent)
+}
+
+func writeFuncFooter(b *buffer, structName string, indent int) {
+	b.addLine("}\n", indent) // Closes the map definition
+
+	s := fmt.Sprintf("func (%s) SwaggerDoc() map[string]string {\n", structName)
+	b.addLine(s, indent)
+	s = fmt.Sprintf("return map_%s\n", structName)
+	b.addLine(s, indent+1)
+	b.addLine("}\n", indent) // Closes the function definition
+}
+
+func writeMapBody(b *buffer, kubeType []Pair, indent int) {
+	format := "\"%s\": \"%s\",\n"
+	for _, pair := range kubeType {
+		s := fmt.Sprintf(format, pair.Name, pair.Doc)
+		b.addLine(s, indent+2)
+	}
+}
+
+// ParseDocumentationFrom gets all types' documentation and returns them as an
+// array. Each type is again represented as an array (we have to use arrays as we
+// need to be sure for the order of the fields). This function returns fields and
+// struct definitions that have no documentation as {name, ""}.
+func ParseDocumentationFrom(src string) []KubeTypes {
+	var docForTypes []KubeTypes
+
+	pkg := astFrom(src)
+
+	for _, kubType := range pkg.Types {
+		if structType, ok := kubType.Decl.Specs[0].(*ast.TypeSpec).Type.(*ast.StructType); ok {
+			var ks KubeTypes
+			ks = append(ks, Pair{kubType.Name, fmtRawDoc(kubType.Doc)})
+
+			for _, field := range structType.Fields.List {
+				if n := fieldName(field); n != "-" {
+					fieldDoc := fmtRawDoc(field.Doc.Text())
+					ks = append(ks, Pair{n, fieldDoc})
+				}
+			}
+			docForTypes = append(docForTypes, ks)
+		}
+	}
+
+	return docForTypes
+}
+
+// WriteSwaggerDocFunc writes a declaration of a function as a string. This function is used in
+// Swagger as a documentation source for structs and theirs fields
+func WriteSwaggerDocFunc(kubeTypes []KubeTypes, w io.Writer) error {
+	for _, kubeType := range kubeTypes {
+		structName := kubeType[0].Name
+		kubeType[0].Name = ""
+
+		// Ignore empty documentation
+		docfulTypes := make(KubeTypes, 0, len(kubeType))
+		for _, pair := range kubeType {
+			if pair.Doc != "" {
+				docfulTypes = append(docfulTypes, pair)
+			}
+		}
+
+		if len(docfulTypes) == 0 {
+			continue // If no fields and the struct have documentation, skip the function definition
+		}
+
+		indent := 0
+		buffer := newBuffer()
+
+		writeFuncHeader(buffer, structName, indent)
+		writeMapBody(buffer, docfulTypes, indent)
+		writeFuncFooter(buffer, structName, indent)
+		buffer.addLine("\n", 0)
+
+		if err := buffer.flushLines(w); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// VerifySwaggerDocsExist writes in a io.Writer a list of structs and fields that
+// are missing of documentation.
+func VerifySwaggerDocsExist(kubeTypes []KubeTypes, w io.Writer) (int, error) {
+	missingDocs := 0
+	buffer := newBuffer()
+
+	for _, kubeType := range kubeTypes {
+		structName := kubeType[0].Name
+		if kubeType[0].Doc == "" {
+			format := "Missing documentation for the struct itself: %s\n"
+			s := fmt.Sprintf(format, structName)
+			buffer.addLine(s, 0)
+			missingDocs++
+		}
+		kubeType = kubeType[1:] // Skip struct definition
+
+		for _, pair := range kubeType { // Iterate only the fields
+			if pair.Doc == "" {
+				format := "In struct: %s, field documentation is missing: %s\n"
+				s := fmt.Sprintf(format, structName, pair.Name)
+				buffer.addLine(s, 0)
+				missingDocs++
+			}
+		}
+	}
+
+	if err := buffer.flushLines(w); err != nil {
+		return -1, err
+	}
+	return missingDocs, nil
+}