✨ feature: route constraints

path.go

@@ -7,9 +7,15 @@
 package fiber
 
 import (
+	"errors"
+	"fmt"
+	"regexp"
 	"strconv"
 	"strings"
+	"time"
+	"unicode"
 
+	"github.com/gofiber/fiber/v2/internal/uuid"
 	"github.com/gofiber/fiber/v2/utils"
 )
 
@@ -33,20 +39,53 @@ type routeSegment struct {
 	IsGreedy    bool   // indicates whether the parameter is greedy or not, is used with wildcard and plus
 	IsOptional  bool   // indicates whether the parameter is optional or not
 	// common information
-	IsLast           bool // shows if the segment is the last one for the route
-	HasOptionalSlash bool // segment has the possibility of an optional slash
-	Length           int  // length of the parameter for segment, when its 0 then the length is undetermined
+	IsLast           bool          // shows if the segment is the last one for the route
+	HasOptionalSlash bool          // segment has the possibility of an optional slash
+	Constraints      []*Constraint // Constraint type if segment is a parameter, if not it will be set to noConstraint by default
+	Length           int           // length of the parameter for segment, when its 0 then the length is undetermined
 	// future TODO: add support for optional groups "/abc(/def)?"
 }
 
 // different special routing signs
 const (
-	wildcardParam    byte = '*'  // indicates a optional greedy parameter
-	plusParam        byte = '+'  // indicates a required greedy parameter
-	optionalParam    byte = '?'  // concludes a parameter by name and makes it optional
-	paramStarterChar byte = ':'  // start character for a parameter with name
-	slashDelimiter   byte = '/'  // separator for the route, unlike the other delimiters this character at the end can be optional
-	escapeChar       byte = '\\' // escape character
+	wildcardParam                byte = '*'  // indicates a optional greedy parameter
+	plusParam                    byte = '+'  // indicates a required greedy parameter
+	optionalParam                byte = '?'  // concludes a parameter by name and makes it optional
+	paramStarterChar             byte = ':'  // start character for a parameter with name
+	slashDelimiter               byte = '/'  // separator for the route, unlike the other delimiters this character at the end can be optional
+	escapeChar                   byte = '\\' // escape character
+	paramConstraintStart         byte = '<'  // start of type constraint for a parameter
+	paramConstraintEnd           byte = '>'  // end of type constraint for a parameter
+	paramConstraintSeparator     byte = ';'  // separator of type constraints for a parameter
+	paramConstraintDataStart     byte = '('  // start of data of type constraint for a parameter
+	paramConstraintDataEnd       byte = ')'  // end of data of type constraint for a parameter
+	paramConstraintDataSeparator byte = ','  // separator of datas of type constraint for a parameter
+)
+
+// parameter constraint types
+type TypeConstraint int16
+
+type Constraint struct {
+	ID   TypeConstraint
+	Data []string
+}
+
+const (
+	noConstraint TypeConstraint = iota
+	intConstraint
+	boolConstraint
+	floatConstraint
+	alphaConstraint
+	datetimeConstraint
+	guidConstraint
+	minLengthConstraint
+	maxLengthConstraint
+	exactLengthConstraint
+	BetweenLengthConstraint
+	minConstraint
+	maxConstraint
+	rangeConstraint
+	regexConstraint
 )
 
 // list of possible parameter and segment delimiter
@@ -59,6 +98,18 @@ var (
 	parameterDelimiterChars = append([]byte{paramStarterChar}, routeDelimiter...)
 	// list of chars to find the end of a parameter
 	parameterEndChars = append([]byte{optionalParam}, parameterDelimiterChars...)
+	// list of parameter constraint start
+	parameterConstraintStartChars = []byte{paramConstraintStart}
+	// list of parameter constraint end
+	parameterConstraintEndChars = []byte{paramConstraintEnd}
+	// list of parameter separator
+	parameterConstraintSeparatorChars = []byte{paramConstraintSeparator}
+	// list of parameter constraint data start
+	parameterConstraintDataStartChars = []byte{paramConstraintDataStart}
+	// list of parameter constraint data end
+	parameterConstraintDataEndChars = []byte{paramConstraintDataEnd}
+	// list of parameter constraint data separator
+	parameterConstraintDataSeparatorChars = []byte{paramConstraintDataSeparator}
 )
 
 // parseRoute analyzes the route and divides it into segments for constant areas and parameters,
@@ -176,6 +227,8 @@ func (routeParser *routeParser) analyseParameterPart(pattern string) (string, *r
 	isWildCard := pattern[0] == wildcardParam
 	isPlusParam := pattern[0] == plusParam
 	parameterEndPosition := findNextNonEscapedCharsetPosition(pattern[1:], parameterEndChars)
+	parameterConstraintStart := -1
+	parameterConstraintEnd := -1
 
 	// handle wildcard end
 	if isWildCard || isPlusParam {
@@ -185,10 +238,47 @@ func (routeParser *routeParser) analyseParameterPart(pattern string) (string, *r
 	} else if !isInCharset(pattern[parameterEndPosition+1], parameterDelimiterChars) {
 		parameterEndPosition++
 	}
+
+	// find constraint part if exists in the parameter part and remove it
+	if parameterEndPosition > 0 {
+		parameterConstraintStart = findNextNonEscapedCharsetPosition(pattern[0:parameterEndPosition], parameterConstraintStartChars)
+		parameterConstraintEnd = findNextNonEscapedCharsetPosition(pattern[0:parameterEndPosition+1], parameterConstraintEndChars)
+
+	}
+
 	// cut params part
 	processedPart := pattern[0 : parameterEndPosition+1]
-
 	paramName := RemoveEscapeChar(GetTrimmedParam(processedPart))
+
+	// Check has constraint
+	var constraints []*Constraint
+
+	if hasConstraint := (parameterConstraintStart != -1 && parameterConstraintEnd != -1); hasConstraint {
+		constraintString := pattern[parameterConstraintStart+1 : parameterConstraintEnd]
+		userconstraints := strings.Split(constraintString, string(parameterConstraintSeparatorChars))
+		constraints = make([]*Constraint, 0, len(userconstraints))
+
+		for _, c := range userconstraints {
+			start := findNextNonEscapedCharsetPosition(c, parameterConstraintDataStartChars)
+			end := findNextNonEscapedCharsetPosition(c, parameterConstraintDataEndChars)
+
+			// Assign constraint
+			if start != -1 && end != -1 {
+				constraints = append(constraints, &Constraint{
+					ID:   getParamConstraintType(c[:start]),
+					Data: strings.Split(RemoveEscapeChar(c[start+1:end]), string(parameterConstraintDataSeparatorChars)),
+				})
+			} else {
+				constraints = append(constraints, &Constraint{
+					ID:   getParamConstraintType(c),
+					Data: []string{},
+				})
+			}
+		}
+
+		paramName = RemoveEscapeChar(GetTrimmedParam(pattern[0:parameterConstraintStart]))
+	}
+
 	// add access iterator to wildcard and plus
 	if isWildCard {
 		routeParser.wildCardCount++
@@ -198,12 +288,18 @@ func (routeParser *routeParser) analyseParameterPart(pattern string) (string, *r
 		paramName += strconv.Itoa(routeParser.plusCount)
 	}
 
-	return processedPart, &routeSegment{
+	segment := &routeSegment{
 		ParamName:  paramName,
 		IsParam:    true,
 		IsOptional: isWildCard || pattern[parameterEndPosition] == optionalParam,
 		IsGreedy:   isWildCard || isPlusParam,
 	}
+
+	if len(constraints) > 0 {
+		segment.Constraints = constraints
+	}
+
+	return processedPart, segment
 }
 
 // isInCharset check is the given character in the charset list
@@ -270,6 +366,14 @@ func (routeParser *routeParser) getMatch(detectionPath, path string, params *[ma
 			}
 			// take over the params positions
 			params[paramsIterator] = path[:i]
+
+			// check constraint
+			for _, c := range segment.Constraints {
+				if matched := c.CheckConstraint(params[paramsIterator]); !matched {
+					return false
+				}
+			}
+
 			paramsIterator++
 		}
 
@@ -368,3 +472,135 @@ func RemoveEscapeChar(word string) string {
 	}
 	return word
 }
+
+func getParamConstraintType(constraintPart string) TypeConstraint {
+	switch constraintPart {
+	case "int":
+		return intConstraint
+	case "bool":
+		return boolConstraint
+	case "float":
+		return floatConstraint
+	case "alpha":
+		return alphaConstraint
+	case "guid":
+		return guidConstraint
+	case "minLen":
+		return minLengthConstraint
+	case "maxLen":
+		return maxLengthConstraint
+	case "exactLen":
+		return exactLengthConstraint
+	case "betweenLen":
+		return BetweenLengthConstraint
+	case "min":
+		return minConstraint
+	case "max":
+		return maxConstraint
+	case "range":
+		return rangeConstraint
+	case "datetime":
+		return datetimeConstraint
+	case "regex":
+		return regexConstraint
+	default:
+		return noConstraint
+	}
+
+}
+
+func (c *Constraint) CheckConstraint(param string) bool {
+	var err error
+	var num int
+
+	// check data exists
+	needOneData := []TypeConstraint{minLengthConstraint, maxLengthConstraint, exactLengthConstraint, minConstraint, maxConstraint, datetimeConstraint, regexConstraint}
+	needTwoData := []TypeConstraint{BetweenLengthConstraint, rangeConstraint}
+
+	for _, data := range needOneData {
+		if c.ID == data && len(c.Data) == 0 {
+			return false
+		}
+	}
+
+	for _, data := range needTwoData {
+		if c.ID == data && len(c.Data) < 2 {
+			return false
+		}
+	}
+
+	switch c.ID {
+	case intConstraint:
+		_, err = strconv.Atoi(param)
+	case boolConstraint:
+		_, err = strconv.ParseBool(param)
+	case floatConstraint:
+		_, err = strconv.ParseFloat(param, 32)
+	case alphaConstraint:
+		for _, r := range param {
+			if !unicode.IsLetter(r) {
+				err = errors.New("")
+			}
+		}
+	case guidConstraint:
+		_, err = uuid.Parse(param)
+	case minLengthConstraint:
+		data, _ := strconv.Atoi(c.Data[0])
+
+		if len(param) < data {
+			err = errors.New("")
+		}
+	case maxLengthConstraint:
+		data, _ := strconv.Atoi(c.Data[0])
+
+		if len(param) > data {
+			err = errors.New("")
+		}
+	case exactLengthConstraint:
+		data, _ := strconv.Atoi(c.Data[0])
+
+		if len(param) != data {
+			err = errors.New("")
+		}
+	case BetweenLengthConstraint:
+		data, _ := strconv.Atoi(c.Data[0])
+		data2, _ := strconv.Atoi(c.Data[1])
+		length := len(param)
+
+		if !(length >= data && length <= data2) {
+			err = errors.New("")
+		}
+	case minConstraint:
+		data, _ := strconv.Atoi(c.Data[0])
+		num, err = strconv.Atoi(param)
+
+		if num < data {
+			err = errors.New("")
+		}
+	case maxConstraint:
+		data, _ := strconv.Atoi(c.Data[0])
+		num, err = strconv.Atoi(param)
+
+		if num > data {
+			err = errors.New("")
+		}
+	case rangeConstraint:
+		data, _ := strconv.Atoi(c.Data[0])
+		data2, _ := strconv.Atoi(c.Data[1])
+		num, err = strconv.Atoi(param)
+
+		if !(num >= data && num <= data2) {
+			err = errors.New("")
+		}
+	case datetimeConstraint:
+		fmt.Print(time.Parse(c.Data[0], param))
+		_, err = time.Parse(c.Data[0], param)
+	case regexConstraint:
+		match, _ := regexp.MatchString(c.Data[0], param)
+		if !match {
+			err = errors.New("")
+		}
+	}
+
+	return err == nil
+}