[go-server] Moved helper code from router and updated logger

Author: Jose Aranguren

modules/openapi-generator/src/main/resources/go-server/helpers.mustache

@@ -2,7 +2,17 @@
 package {{packageName}}
 
 import (
+	"encoding/json"
+	"errors"
+	"io"
+	"mime/multipart"
+	"net/http"
+	"net/url"
+	"os"
 	"reflect"
+	"strconv"
+	"strings"
+	"time"
 )
 
 // Response return a ImplResponse struct filled
@@ -64,3 +74,292 @@ func AssertRecurseValueRequired[T any](value reflect.Value, callback func(T) err
 	}
 	return nil
 }
+
+// EncodeJSONResponse uses the json encoder to write an interface to the http response with an optional status code
+func EncodeJSONResponse(i interface{}, status *int,{{#addResponseHeaders}} headers map[string][]string,{{/addResponseHeaders}} w http.ResponseWriter) error {
+	wHeader := w.Header()
+	{{#addResponseHeaders}}
+	for key, values := range headers {
+		for _, value := range values {
+			wHeader.Add(key, value)
+		}
+	}
+	{{/addResponseHeaders}}
+
+	f, ok := i.(*os.File)
+	if ok {
+		data, err := io.ReadAll(f)
+		if err != nil {
+			return err
+		}
+		wHeader.Set("Content-Type", http.DetectContentType(data))
+		wHeader.Set("Content-Disposition", "attachment; filename="+f.Name())
+		if status != nil {
+			w.WriteHeader(*status)
+		} else {
+			w.WriteHeader(http.StatusOK)
+		}
+		_, err = w.Write(data)
+		return err
+	}
+	wHeader.Set("Content-Type", "application/json; charset=UTF-8")
+
+	if status != nil {
+		w.WriteHeader(*status)
+	} else {
+		w.WriteHeader(http.StatusOK)
+	}
+
+	if i != nil {
+		return json.NewEncoder(w).Encode(i)
+	}
+
+	return nil
+}
+
+// ReadFormFileToTempFile reads file data from a request form and writes it to a temporary file
+func ReadFormFileToTempFile(r *http.Request, key string) (*os.File, error) {
+	_, fileHeader, err := r.FormFile(key)
+	if err != nil {
+		return nil, err
+	}
+
+	return readFileHeaderToTempFile(fileHeader)
+}
+
+// ReadFormFilesToTempFiles reads files array data from a request form and writes it to a temporary files
+func ReadFormFilesToTempFiles(r *http.Request, key string) ([]*os.File, error) {
+	if err := r.ParseMultipartForm(32 << 20); err != nil {
+		return nil, err
+	}
+
+	files := make([]*os.File, 0, len(r.MultipartForm.File[key]))
+
+	for _, fileHeader := range r.MultipartForm.File[key] {
+		file, err := readFileHeaderToTempFile(fileHeader)
+		if err != nil {
+			return nil, err
+		}
+
+		files = append(files, file)
+	}
+
+	return files, nil
+}
+
+// readFileHeaderToTempFile reads multipart.FileHeader and writes it to a temporary file
+func readFileHeaderToTempFile(fileHeader *multipart.FileHeader) (*os.File, error) {
+	formFile, err := fileHeader.Open()
+	if err != nil {
+		return nil, err
+	}
+
+	defer formFile.Close()
+
+	// Use .* as suffix, because the asterisk is a placeholder for the random value,
+	// and the period allows consumers of this file to remove the suffix to obtain the original file name
+	file, err := os.CreateTemp("", fileHeader.Filename+".*")
+	if err != nil {
+		return nil, err
+	}
+
+	defer file.Close()
+
+	_, err = io.Copy(file, formFile)
+	if err != nil {
+		return nil, err
+	}
+	
+	return file, nil
+}
+
+func parseTimes(param string) ([]time.Time, error) {
+	splits := strings.Split(param, ",")
+	times := make([]time.Time, 0, len(splits))
+	for _, v := range splits {
+		t, err := parseTime(v)
+		if err != nil {
+			return nil, err
+		}
+		times = append(times, t)
+	}
+	return times, nil
+}
+
+// parseTime will parses a string parameter into a time.Time using the RFC3339 format
+func parseTime(param string) (time.Time, error) {
+	if param == "" {
+		return time.Time{}, nil
+	}
+	return time.Parse(time.RFC3339, param)
+}
+
+type Number interface {
+	~int32 | ~int64 | ~float32 | ~float64
+}
+
+type ParseString[T Number | string | bool] func(v string) (T, error)
+
+// parseFloat64 parses a string parameter to an float64.
+func parseFloat64(param string) (float64, error) {
+	if param == "" {
+		return 0, nil
+	}
+
+	return strconv.ParseFloat(param, 64)
+}
+
+// parseFloat32 parses a string parameter to an float32.
+func parseFloat32(param string) (float32, error) {
+	if param == "" {
+		return 0, nil
+	}
+
+	v, err := strconv.ParseFloat(param, 32)
+	return float32(v), err
+}
+
+// parseInt64 parses a string parameter to an int64.
+func parseInt64(param string) (int64, error) {
+	if param == "" {
+		return 0, nil
+	}
+
+	return strconv.ParseInt(param, 10, 64)
+}
+
+// parseInt32 parses a string parameter to an int32.
+func parseInt32(param string) (int32, error) {
+	if param == "" {
+		return 0, nil
+	}
+
+	val, err := strconv.ParseInt(param, 10, 32)
+	return int32(val), err
+}
+
+// parseBool parses a string parameter to an bool.
+func parseBool(param string) (bool, error) {
+	if param == "" {
+		return false, nil
+	}
+
+	return strconv.ParseBool(param)
+}
+
+type Operation[T Number | string | bool] func(actual string) (T, bool, error)
+
+func WithRequire[T Number | string | bool](parse ParseString[T]) Operation[T] {
+	var empty T
+	return func(actual string) (T, bool, error) {
+		if actual == "" {
+			return empty, false, errors.New(errMsgRequiredMissing)
+		}
+
+		v, err := parse(actual)
+		return v, false, err
+	}
+}
+
+func WithDefaultOrParse[T Number | string | bool](def T, parse ParseString[T]) Operation[T] {
+	return func(actual string) (T, bool, error) {
+		if actual == "" {
+			return def, true, nil
+		}
+
+		v, err := parse(actual)
+		return v, false, err
+	}
+}
+
+func WithParse[T Number | string | bool](parse ParseString[T]) Operation[T] {
+	return func(actual string) (T, bool, error) {
+		v, err := parse(actual)
+		return v, false, err
+	}
+}
+
+type Constraint[T Number | string | bool] func(actual T) error
+
+func WithMinimum[T Number](expected T) Constraint[T] {
+	return func(actual T) error {
+		if actual < expected {
+			return errors.New(errMsgMinValueConstraint)
+		}
+
+		return nil
+	}
+}
+
+func WithMaximum[T Number](expected T) Constraint[T] {
+	return func(actual T) error {
+		if actual > expected {
+			return errors.New(errMsgMaxValueConstraint)
+		}
+
+		return nil
+	}
+}
+
+// parseNumericParameter parses a numeric parameter to its respective type.
+func parseNumericParameter[T Number](param string, fn Operation[T], checks ...Constraint[T]) (T, error) {
+	v, ok, err := fn(param)
+	if err != nil {
+		return 0, err
+	}
+
+	if !ok {
+		for _, check := range checks {
+			if err := check(v); err != nil {
+				return 0, err
+			}
+		}
+	}
+
+	return v, nil
+}
+
+// parseBoolParameter parses a string parameter to a bool
+func parseBoolParameter(param string, fn Operation[bool]) (bool, error) {
+	v, _, err := fn(param)
+	return v, err
+}
+
+// parseNumericArrayParameter parses a string parameter containing array of values to its respective type.
+func parseNumericArrayParameter[T Number](param, delim string, required bool, fn Operation[T], checks ...Constraint[T]) ([]T, error) {
+	if param == "" {
+		if required {
+			return nil, errors.New(errMsgRequiredMissing)
+		}
+
+		return nil, nil
+	}
+
+	str := strings.Split(param, delim)
+	values := make([]T, len(str))
+
+	for i, s := range str {
+		v, ok, err := fn(s)
+		if err != nil {
+			return nil, err
+		}
+
+		if !ok {
+			for _, check := range checks {
+				if err := check(v); err != nil {
+					return nil, err
+				}
+			}
+		}
+
+		values[i] = v
+	}
+
+	return values, nil
+}
+
+
+// parseQuery parses query parameters and returns an error if any malformed value pairs are encountered.
+func parseQuery(rawQuery string) (url.Values, error) {
+	return url.ParseQuery(rawQuery)
+}

modules/openapi-generator/src/main/resources/go-server/logger.mustache

@@ -5,8 +5,15 @@ import (
 	"log"
 	"net/http"
 	"time"
+{{#routers}}
+	{{#chi}}
+	"github.com/go-chi/chi/v5/middleware"
+	{{/chi}}
+{{/routers}}
 )
 
+{{#routers}}
+{{#mux}}
 func Logger(inner http.Handler, name string) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		start := time.Now()
@@ -22,3 +29,10 @@ func Logger(inner http.Handler, name string) http.Handler {
 		)
 	})
 }
+{{/mux}}
+{{#chi}}
+func Logger(inner http.Handler) http.Handler {
+	return middleware.Logger(inner)
+}
+{{/chi}}
+{{/routers}}