v0.0.483

exerr/dataType.go

@@ -23,6 +23,7 @@ var (
 	TypeInternal       = NewType("INTERNAL_ERROR", langext.Ptr(500))
 	TypePanic          = NewType("PANIC", langext.Ptr(500))
 	TypeNotImplemented = NewType("NOT_IMPLEMENTED", langext.Ptr(500))
+	TypeAssert         = NewType("ASSERT", langext.Ptr(500))
 
 	TypeMongoQuery        = NewType("MONGO_QUERY", langext.Ptr(500))
 	TypeCursorTokenDecode = NewType("CURSOR_TOKEN_DECODE", langext.Ptr(500))

ginext/engine.go

@@ -218,3 +218,7 @@ func (w *GinWrapper) ServeHTTP(req *http.Request) *httptest.ResponseRecorder {
 func (w *GinWrapper) ForwardRequest(writer http.ResponseWriter, req *http.Request) {
 	w.engine.ServeHTTP(writer, req)
 }
+
+func (w *GinWrapper) ListRoutes() []gin.RouteInfo {
+	return w.engine.Routes()
+}

ginext/preContext.go

@@ -15,16 +15,17 @@ import (
 )
 
 type PreContext struct {
-	ginCtx         *gin.Context
-	wrapper        *GinWrapper
-	uri            any
-	query          any
-	body           any
-	rawbody        *[]byte
-	form           any
-	header         any
-	timeout        *time.Duration
-	persistantData *preContextData // must be a ptr, so that we can get the values back in out Wrap func
+	ginCtx                 *gin.Context
+	wrapper                *GinWrapper
+	uri                    any
+	query                  any
+	body                   any
+	rawbody                *[]byte
+	form                   any
+	header                 any
+	timeout                *time.Duration
+	persistantData         *preContextData // must be a ptr, so that we can get the values back in out Wrap func
+	ignoreWrongContentType bool
 }
 
 type preContextData struct {
@@ -71,7 +72,12 @@ func (pctx *PreContext) WithSession(sessionObj SessionObject) *PreContext {
 	return pctx
 }
 
-func (pctx PreContext) Start() (*AppContext, *gin.Context, *HTTPResponse) {
+func (pctx *PreContext) IgnoreWrongContentType() *PreContext {
+	pctx.ignoreWrongContentType = true
+	return pctx
+}
+
+func (pctx PreContext) Start() (*AppContext, *gin.Context, *InspectableHTTPErrorResponse) {
 	if pctx.uri != nil {
 		if err := pctx.ginCtx.ShouldBindUri(pctx.uri); err != nil {
 			err = exerr.Wrap(err, "Failed to read uri").
@@ -102,10 +108,12 @@ func (pctx PreContext) Start() (*AppContext, *gin.Context, *HTTPResponse) {
 				return nil, nil, langext.Ptr(Error(err))
 			}
 		} else {
-			err := exerr.New(exerr.TypeBindFailJSON, "missing JSON body").
-				Str("struct_type", fmt.Sprintf("%T", pctx.body)).
-				Build()
-			return nil, nil, langext.Ptr(Error(err))
+			if !pctx.ignoreWrongContentType {
+				err := exerr.New(exerr.TypeBindFailJSON, "missing JSON body").
+					Str("struct_type", fmt.Sprintf("%T", pctx.body)).
+					Build()
+				return nil, nil, langext.Ptr(Error(err))
+			}
 		}
 	}
 
@@ -144,10 +152,12 @@ func (pctx PreContext) Start() (*AppContext, *gin.Context, *HTTPResponse) {
 				return nil, nil, langext.Ptr(Error(err))
 			}
 		} else {
-			err := exerr.New(exerr.TypeBindFailFormData, "missing form body").
-				Str("struct_type", fmt.Sprintf("%T", pctx.form)).
-				Build()
-			return nil, nil, langext.Ptr(Error(err))
+			if !pctx.ignoreWrongContentType {
+				err := exerr.New(exerr.TypeBindFailFormData, "missing form body").
+					Str("struct_type", fmt.Sprintf("%T", pctx.form)).
+					Build()
+				return nil, nil, langext.Ptr(Error(err))
+			}
 		}
 	}
 

ginext/response.go

@@ -36,6 +36,13 @@ type InspectableHTTPResponse interface {
 	Headers() []string
 }
 
+type InspectableHTTPErrorResponse interface {
+	HTTPResponse
+	InspectableHTTPResponse
+
+	Error() error
+}
+
 func NotImplemented() HTTPResponse {
 	return Error(exerr.New(exerr.TypeNotImplemented, "").Build())
 }

ginext/responseJsonAPI.go

@@ -13,6 +13,10 @@ type jsonAPIErrResponse struct {
 	cookies []cookieval
 }
 
+func (j jsonAPIErrResponse) Error() error {
+	return j.err
+}
+
 func (j jsonAPIErrResponse) Write(g *gin.Context) {
 	for _, v := range j.headers {
 		g.Header(v.Key, v.Val)
@@ -64,7 +68,7 @@ func (j jsonAPIErrResponse) Unwrap() error {
 	return j.err
 }
 
-func Error(e error) HTTPResponse {
+func Error(e error) InspectableHTTPErrorResponse {
 	return &jsonAPIErrResponse{
 		err: exerr.FromError(e),
 	}

go.mod

@@ -9,9 +9,9 @@ require (
 	github.com/rs/xid v1.5.0
 	github.com/rs/zerolog v1.33.0
 	go.mongodb.org/mongo-driver v1.16.0
-	golang.org/x/crypto v0.24.0
-	golang.org/x/sys v0.21.0
-	golang.org/x/term v0.21.0
+	golang.org/x/crypto v0.25.0
+	golang.org/x/sys v0.22.0
+	golang.org/x/term v0.22.0
 )
 
 require (
@@ -55,7 +55,7 @@ require (
 	github.com/youmark/pkcs8 v0.0.0-20240424034433-3c2c7870ae76 // indirect
 	golang.org/x/arch v0.8.0 // indirect
 	golang.org/x/image v0.18.0 // indirect
-	golang.org/x/net v0.26.0 // indirect
+	golang.org/x/net v0.27.0 // indirect
 	golang.org/x/text v0.16.0 // indirect
 	google.golang.org/protobuf v1.34.2 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect

go.sum

@@ -249,6 +249,8 @@ golang.org/x/crypto v0.23.0 h1:dIJU/v2J8Mdglj/8rJ6UUOM3Zc9zLZxVZwwxMooUSAI=
 golang.org/x/crypto v0.23.0/go.mod h1:CKFgDieR+mRhux2Lsu27y0fO304Db0wZe70UKqHu0v8=
 golang.org/x/crypto v0.24.0 h1:mnl8DM0o513X8fdIkmyFE/5hTYxbwYOjDS/+rK6qpRI=
 golang.org/x/crypto v0.24.0/go.mod h1:Z1PMYSOR5nyMcyAVAIQSKCDwalqy85Aqn1x3Ws4L5DM=
+golang.org/x/crypto v0.25.0 h1:ypSNr+bnYL2YhwoMt2zPxHFmbAN1KZs/njMG3hxUp30=
+golang.org/x/crypto v0.25.0/go.mod h1:T+wALwcMOSE0kXgUAnPAHqTLW+XHgcELELW8VaDgm/M=
 golang.org/x/image v0.0.0-20190910094157-69e4b8554b2a/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8 h1:hVwzHzIUGRjiF7EcUjqNxk3NCfkPxbDKRdnNE1Rpg0U=
 golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
@@ -278,6 +280,8 @@ golang.org/x/net v0.25.0 h1:d/OCCoBEUq33pjydKrGQhw7IlUPI2Oylr+8qLx49kac=
 golang.org/x/net v0.25.0/go.mod h1:JkAGAh7GEvH74S6FOH42FLoXpXbE/aqXSrIQjXgsiwM=
 golang.org/x/net v0.26.0 h1:soB7SVo0PWrY4vPW/+ay0jKDNScG2X9wFeYlXIvJsOQ=
 golang.org/x/net v0.26.0/go.mod h1:5YKkiSynbBIh3p6iOc/vibscux0x38BZDkn8sCUPxHE=
+golang.org/x/net v0.27.0 h1:5K3Njcw06/l2y9vpGCSdcxWOYHOUk3dVNGDXN+FvAys=
+golang.org/x/net v0.27.0/go.mod h1:dDi0PyhWNoiUOrAS8uXv/vnScO4wnHQO4mj9fn/RytE=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.6.0 h1:5BMeUDZ7vkXGfEr1x9B4bRcTH4lpkTkpdh0T/J+qjbQ=
@@ -307,6 +311,8 @@ golang.org/x/sys v0.20.0 h1:Od9JTbYCk261bKm4M/mw7AklTlFYIa0bIp9BgSm1S8Y=
 golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/sys v0.21.0 h1:rF+pYz3DAGSQAxAu1CbC7catZg4ebC4UIeIhKxBZvws=
 golang.org/x/sys v0.21.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.22.0 h1:RI27ohtqKCnwULzJLqkv897zojh5/DwS/ENaMzUOaWI=
+golang.org/x/sys v0.22.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
 golang.org/x/term v0.16.0 h1:m+B6fahuftsE9qjo0VWp2FW0mB3MTJvR0BaMQrq0pmE=
@@ -321,6 +327,8 @@ golang.org/x/term v0.20.0 h1:VnkxpohqXaOBYJtBmEppKUG6mXpi+4O6purfc2+sMhw=
 golang.org/x/term v0.20.0/go.mod h1:8UkIAJTvZgivsXaD6/pH6U9ecQzZ45awqEOzuCvwpFY=
 golang.org/x/term v0.21.0 h1:WVXCp+/EBEHOj53Rvu+7KiT/iElMrO8ACK16SMZ3jaA=
 golang.org/x/term v0.21.0/go.mod h1:ooXLefLobQVslOqselCNF4SxFAaoS6KujMbsGzSDmX0=
+golang.org/x/term v0.22.0 h1:BbsgPEJULsl2fV/AT3v15Mjva5yXKQDyKf+TbDz7QJk=
+golang.org/x/term v0.22.0/go.mod h1:F3qCibpT5AMpCRfhfT53vVJwhLtIVHhB9XDjfFvnMI4=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=

goextVersion.go

@@ -1,5 +1,5 @@
 package goext
 
-const GoextVersion = "0.0.476"
+const GoextVersion = "0.0.483"
 
-const GoextVersionTimestamp = "2024-06-28T18:37:02+0200"
+const GoextVersionTimestamp = "2024-07-16T15:08:37+0200"

langext/string.go

@@ -88,12 +88,15 @@ func StrRunePadRight(str string, pad string, padlen int) string {
 
 func Indent(str string, pad string) string {
 	eonl := strings.HasSuffix(str, "\n")
+	if eonl {
+		str = str[0 : len(str)-1]
+	}
 	r := ""
 	for _, v := range strings.Split(str, "\n") {
 		r += pad + v + "\n"
 	}
 
-	if eonl {
+	if !eonl {
 		r = r[0 : len(r)-1]
 	}
 
@@ -115,3 +118,21 @@ func StrRepeat(val string, count int) string {
 	}
 	return r
 }
+
+func StrWrap(val string, linelen int, seperator string) string {
+	res := ""
+
+	for iPos := 0; ; {
+		next := min(iPos+linelen, len(val))
+		res += val[iPos:next]
+
+		iPos = next
+		if iPos >= len(val) {
+			break
+		}
+
+		res += seperator
+	}
+
+	return res
+}

langext/string_test.go

@@ -0,0 +1,152 @@
+package langext
+
+import "testing"
+
+func TestStrLimitBehaviour(t *testing.T) {
+	val := "Hello, World!"
+	maxlen := 5
+	suffix := "..."
+	expected := "He..."
+	result := StrLimit(val, maxlen, suffix)
+	if result != expected {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestStrSplitBehaviour1(t *testing.T) {
+	val := "Hello,World,,"
+	sep := ","
+	expected := []string{"Hello", "World"}
+	result := StrSplit(val, sep, false)
+	if len(result) != len(expected) {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestStrSplitBehaviour2(t *testing.T) {
+	val := "Hello,World,,"
+	sep := ","
+	expected := []string{"Hello", "World", "", ""}
+	result := StrSplit(val, sep, true)
+	if len(result) != len(expected) {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestStrPadRightBehaviour(t *testing.T) {
+	str := "Hello"
+	pad := "*"
+	padlen := 10
+	expected := "Hello*****"
+	result := StrPadRight(str, pad, padlen)
+	if result != expected {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestStrPadLeftBehaviour(t *testing.T) {
+	str := "Hello"
+	pad := "*"
+	padlen := 10
+	expected := "*****Hello"
+	result := StrPadLeft(str, pad, padlen)
+	if result != expected {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestStrRunePadLeftBehaviour(t *testing.T) {
+	str := "Hello"
+	pad := "*"
+	padlen := 10
+	expected := "*****Hello"
+	result := StrRunePadLeft(str, pad, padlen)
+	if result != expected {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestStrRunePadRightBehaviour(t *testing.T) {
+	str := "Hello"
+	pad := "*"
+	padlen := 10
+	expected := "Hello*****"
+	result := StrRunePadRight(str, pad, padlen)
+	if result != expected {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestIndentBehaviour1(t *testing.T) {
+	str := "Hello\nWorld"
+	pad := ".."
+	expected := "..Hello\n..World"
+	result := Indent(str, pad)
+	if result != expected {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestIndentBehaviour2(t *testing.T) {
+	str := "Hello\nWorld\n"
+	pad := ".."
+	expected := "..Hello\n..World\n"
+	result := Indent(str, pad)
+	if result != expected {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestStrRepeatBehaviour(t *testing.T) {
+	val := "Hello"
+	count := 3
+	expected := "HelloHelloHello"
+	result := StrRepeat(val, count)
+	if result != expected {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestStrWrapBehaviour1(t *testing.T) {
+	val := "123456789"
+	linelen := 5
+	seperator := "\n"
+	expected := "12345\n6789"
+	result := StrWrap(val, linelen, seperator)
+	if result != expected {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestStrWrapBehaviour2(t *testing.T) {
+	val := "1234567890"
+	linelen := 5
+	seperator := "\n"
+	expected := "12345\n67890"
+	result := StrWrap(val, linelen, seperator)
+	if result != expected {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestStrWrapBehaviour3(t *testing.T) {
+	val := "****************"
+	linelen := 4
+	seperator := "\n"
+	expected := "****\n****\n****\n****"
+	result := StrWrap(val, linelen, seperator)
+	if result != expected {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}
+
+func TestStrWrapBehaviour4(t *testing.T) {
+	val := "*****************"
+	linelen := 4
+	seperator := "\n"
+	expected := "****\n****\n****\n****\n*"
+	result := StrWrap(val, linelen, seperator)
+	if result != expected {
+		t.Errorf("Expected %v but got %v", expected, result)
+	}
+}

mathext/statistics.go

@@ -1,6 +1,9 @@
 package mathext
 
-import "gogs.mikescher.com/BlackForestBytes/goext/langext"
+import (
+	"gogs.mikescher.com/BlackForestBytes/goext/exerr"
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+)
 
 func Sum[T langext.NumberConstraint](v []T) T {
 	total := T(0)
@@ -41,3 +44,53 @@ func ArrMax[T langext.OrderedConstraint](v []T) T {
 	}
 	return r
 }
+
+func MustPercentile[T langext.NumberConstraint](rawdata []T, percentile float64) T {
+	v, err := Percentile(rawdata, percentile)
+	if err != nil {
+		panic(err)
+	}
+	return v
+}
+
+func Percentile[T langext.NumberConstraint](rawdata []T, percentile float64) (T, error) {
+	v, err := FloatPercentile(rawdata, percentile)
+	if err != nil {
+		return T(0), err
+	}
+	return T(v), nil
+
+}
+
+func FloatPercentile[T langext.NumberConstraint](rawdata []T, percentile float64) (float64, error) {
+	if len(rawdata) == 0 {
+		return 0, exerr.New(exerr.TypeAssert, "no data to calculate percentile").Any("percentile", percentile).Build()
+	}
+
+	if percentile < 0 || percentile > 100 {
+		return 0, exerr.New(exerr.TypeAssert, "percentile out of range").Any("percentile", percentile).Build()
+	}
+
+	data := langext.ArrCopy(rawdata)
+	langext.Sort(data)
+
+	idxFloat := float64(len(data)-1) * (percentile / float64(100))
+
+	idxInt := int(idxFloat)
+
+	// exact match on index
+	if idxFloat == float64(idxInt) {
+		return float64(data[idxInt]), nil
+	}
+
+	// linear interpolation
+	v1 := data[idxInt]
+	v2 := data[idxInt+1]
+
+	weight := idxFloat - float64(idxInt)
+
+	valFloat := (float64(v1) * (1 - weight)) + (float64(v2) * weight)
+
+	return valFloat, nil
+
+}

mathext/statistics_test.go

@@ -0,0 +1,238 @@
+package mathext
+
+import (
+	"math"
+	"testing"
+)
+
+func TestSumIntsHappyPath(t *testing.T) {
+	values := []int{1, 2, 3, 4, 5}
+	expected := 15
+	result := Sum(values)
+	if result != expected {
+		t.Errorf("Sum of %v; expected %v, got %v", values, expected, result)
+	}
+}
+
+func TestSumFloatsHappyPath(t *testing.T) {
+	values := []float64{1.1, 2.2, 3.3}
+	expected := 6.6
+	result := Sum(values)
+	if result != expected {
+		t.Errorf("Sum of %v; expected %v, got %v", values, expected, result)
+	}
+}
+
+func TestMeanOfInts(t *testing.T) {
+	values := []float64{1, 2, 3, 4, 5}
+	expected := 3.0
+	result := Mean(values)
+	if result != expected {
+		t.Errorf("Mean of %v; expected %v, got %v", values, expected, result)
+	}
+}
+
+func TestMedianOddNumberOfElements(t *testing.T) {
+	values := []float64{1, 2, 3, 4, 5}
+	expected := 3.0
+	result := Median(values)
+	if result != expected {
+		t.Errorf("Median of %v; expected %v, got %v", values, expected, result)
+	}
+}
+
+func TestMedianEvenNumberOfElements(t *testing.T) {
+	values := []float64{1, 2, 3, 4, 5, 6}
+	expected := 3.5
+	result := Median(values)
+	if result != expected {
+		t.Errorf("Median of %v; expected %v, got %v", values, expected, result)
+	}
+}
+
+func TestArrMinInts(t *testing.T) {
+	values := []int{5, 3, 9, 1, 4}
+	expected := 1
+	result := ArrMin(values)
+	if result != expected {
+		t.Errorf("ArrMin of %v; expected %v, got %v", values, expected, result)
+	}
+}
+
+func TestArrMaxInts(t *testing.T) {
+	values := []int{5, 3, 9, 1, 4}
+	expected := 9
+	result := ArrMax(values)
+	if result != expected {
+		t.Errorf("ArrMax of %v; expected %v, got %v", values, expected, result)
+	}
+}
+
+func TestPercentileValidInput(t *testing.T) {
+	values := []int{1, 2, 3, 4, 5}
+	percentile := 50.0
+	expected := 3
+	result, err := Percentile(values, percentile)
+	if err != nil || result != expected {
+		t.Errorf("Percentile %v of %v; expected %v, got %v, err: %v", percentile, values, expected, result, err)
+	}
+}
+
+func TestPercentileOutOfRange(t *testing.T) {
+	values := []int{1, 2, 3, 4, 5}
+	percentile := 150.0
+	_, err := Percentile(values, percentile)
+	if err == nil {
+		t.Errorf("Expected error for percentile %v out of range, got nil", percentile)
+	}
+}
+
+func TestPercentileValueInArray(t *testing.T) {
+	values := []int{1, 3, 5, 7, 9}
+	percentile := 40.0
+	expected := 4
+	result, err := Percentile(values, percentile)
+	if err != nil || result != expected {
+		t.Errorf("Percentile %v of %v; expected %v, got %v, err: %v", percentile, values, expected, result, err)
+	}
+}
+
+func TestFloatPercentileValueInArray(t *testing.T) {
+	values := []int{1, 3, 5, 7, 9}
+	percentile := 40.0
+	expected := 4.2
+	result, err := FloatPercentile(values, percentile)
+	if err != nil || result != expected {
+		t.Errorf("Percentile %v of %v; expected %v, got %v, err: %v", percentile, values, expected, result, err)
+	}
+}
+
+func TestPercentileInterpolation(t *testing.T) {
+	values := []float64{1.0, 2.0, 3.0, 4.0, 5.0}
+	percentile := 25.0
+	expected := 2.0
+	result, err := Percentile(values, percentile)
+	if err != nil || result != expected {
+		t.Errorf("Percentile %v of %v; expected %v, got %v, err: %v", percentile, values, expected, result, err)
+	}
+}
+
+func TestPercentileSingleValue(t *testing.T) {
+	values := []int{10}
+	percentile := 50.0
+	expected := 10
+	result, err := Percentile(values, percentile)
+	if err != nil || result != expected {
+		t.Errorf("Percentile %v of %v; expected %v, got %v, err: %v", percentile, values, expected, result, err)
+	}
+}
+
+func TestPercentileExactlyBetweenTwoValues(t *testing.T) {
+	values := []float64{1, 2, 3, 4, 5}
+	percentile := 62.5 // Exactly between 3 and 4
+	expected := 3.5
+	result, err := FloatPercentile(values, percentile)
+	if err != nil || result != expected {
+		t.Errorf("Percentile %v of %v; expected %v, got %v, err: %v", percentile, values, expected, result, err)
+	}
+}
+
+func TestPercentileTwoThirdsBetweenTwoValues(t *testing.T) {
+	values := []float64{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+	percentile := 66.666666666666
+	expected := 6.666666666666667 // Since 2/3 of the way between 6 and 7 is 6.666...
+	result, err := Percentile(values, percentile)
+	if err != nil || math.Abs(result-expected) > 1e-9 {
+		t.Errorf("Percentile %v of %v; expected %v, got %v, err: %v", percentile, values, expected, result, err)
+	}
+}
+
+func TestPercentileBetweenTwoValues1(t *testing.T) {
+	values := []float64{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+	percentile := 11.0
+	expected := 1.1
+	result, err := Percentile(values, percentile)
+	if err != nil || math.Abs(result-expected) > 1e-9 {
+		t.Errorf("Percentile %v of %v; expected %v, got %v, err: %v", percentile, values, expected, result, err)
+	}
+}
+
+func TestPercentileBetweenTwoValues2(t *testing.T) {
+	values := []float64{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+	percentile := 9.0
+	expected := 0.9
+	result, err := Percentile(values, percentile)
+	if err != nil || math.Abs(result-expected) > 1e-9 {
+		t.Errorf("Percentile %v of %v; expected %v, got %v, err: %v", percentile, values, expected, result, err)
+	}
+}
+
+func TestPercentileUnsortedInput(t *testing.T) {
+	values := []float64{5, 1, 4, 2, 3} // Unsorted input
+	percentile := 50.0
+	expected := 3.0
+	result, err := Percentile(values, percentile)
+	if err != nil || result != expected {
+		t.Errorf("Percentile %v of %v; expected %v, got %v, err: %v", percentile, values, expected, result, err)
+	}
+}
+
+func TestPercentileUnsortedInputLowPercentile(t *testing.T) {
+	values := []float64{10, 6, 7, 3, 2, 9, 8, 1, 4, 5} // Unsorted input
+	percentile := 10.0
+	expected := 1.9 // Expecting interpolation between 1 and 2
+	result, err := Percentile(values, percentile)
+	if err != nil || result != expected {
+		t.Errorf("Percentile %v of %v; expected %v, got %v, err: %v", percentile, values, expected, result, err)
+	}
+}
+
+func TestPercentileUnsortedInputHighPercentile(t *testing.T) {
+	values := []float64{10, 6, 7, 3, 2, 9, 8, 1, 4, 5} // Unsorted input
+	percentile := 90.0
+	expected := 9.1 // Expecting interpolation between 9 and 10
+	result, err := Percentile(values, percentile)
+	if err != nil || result != expected {
+		t.Errorf("Percentile %v of %v; expected %v, got %v, err: %v", percentile, values, expected, result, err)
+	}
+}
+
+func TestFloatPercentileExactValueFromInput(t *testing.T) {
+	values := []float64{1.5, 2.5, 3.5, 4.5, 5.5}
+	percentile := 50.0 // Exact value from input array should be 3.5
+	expected := 3.5
+	result, err := FloatPercentile(values, percentile)
+	if err != nil || result != expected {
+		t.Errorf("FloatPercentile %v of %v; expected %v, got %v, err: %v", percentile, values, expected, result, err)
+	}
+}
+
+func TestFloatPercentileInterpolatedValue(t *testing.T) {
+	values := []float64{1.0, 2.0, 3.0, 4.0, 5.0}
+	percentile := 87.5 // Interpolated value between 4.0 and 5.0
+	expected := 4.5
+	result, err := FloatPercentile(values, percentile)
+	if err != nil || result != expected {
+		t.Errorf("FloatPercentile %v of %v; expected %v, got %v, err: %v", percentile, values, expected, result, err)
+	}
+}
+
+func TestFloatPercentileUnsortedInputExactValue(t *testing.T) {
+	values := []float64{5.5, 1.5, 4.5, 2.5, 3.5} // Unsorted input
+	percentile := 50.0
+	expected := 3.5
+	result, err := FloatPercentile(values, percentile)
+	if err != nil || result != expected {
+		t.Errorf("FloatPercentile %v of %v; expected %v, got %v, err: %v", percentile, values, expected, result, err)
+	}
+}
+
+func TestFloatPercentileUnsortedInputInterpolatedValue(t *testing.T) {
+	values := []float64{10.5, 6.5, 7.5, 3.5, 2.5, 9.5, 8.5, 1.5, 4.5, 5.5}
+	percentile := 80.0 // Interpolated value between 4.0 and 5.0
+	expected := 8.7
+	result, err := FloatPercentile(values, percentile)
+	if err != nil || math.Abs(result-expected) > 1e-9 {
+		t.Errorf("FloatPercentile %v of %v; expected %v, got %v, err: %v", percentile, values, expected, result, err)
+	}
+}

reflectext/structAccess.go

@@ -0,0 +1,185 @@
+package reflectext
+
+import (
+	"errors"
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"reflect"
+	"strconv"
+	"strings"
+)
+
+var ErrAccessStructInvalidFieldType = errors.New("invalid field type")
+var ErrAccessStructFieldInPathWasNil = errors.New("a field in the path was nil")
+var ErrAccessStructInvalidArrayIndex = errors.New("invalid array index")
+var ErrAccessStructInvalidMapKey = errors.New("invalid map key")
+var ErrAccessStructArrayAccess = errors.New("trying to access array")
+var ErrAccessStructMapAccess = errors.New("trying to access map")
+var ErrAccessStructMissingField = errors.New("missing field")
+
+type AccessStructOpt struct {
+	ReturnNilOnMissingFields          bool    // return nil (instead of error) when a field in the path is missing (aka the supplied path is wrong)
+	ReturnNilOnNilPtrFields           bool    // return nil (instead of error) when a field in the path is nil
+	ReturnNilOnWrongFinalFieldType    bool    // return nil (instead of error) when the (final) field is not of the requested generic type
+	ReturnNilOnWrongIntermedFieldType bool    // return nil (instead of error) when the intermediate field has an invalid type
+	ReturnNilOnInvalidArrayIndizes    bool    // return nil (instead of error) when trying to acces an array with an invalid index (not a number or out of range)
+	ReturnNilOnMissingMapKeys         bool    // return nil (instead of error) when trying to access a map with a missing key
+	UsedTagForKeys                    *string // Use this tag for key names in the struct (instead of the StructField.Name)
+	PreventArrayAccess                bool    // do not access array indizes - throw an error instead
+	PreventMapAccess                  bool    // do not access maps - throw an error instead
+}
+
+func AccessJSONStruct[TResult any](v any, path string) (TResult, error) {
+	return AccessStructByStringPath[TResult](v, path, AccessStructOpt{UsedTagForKeys: langext.Ptr("json")})
+}
+
+func AccessStruct[TResult any](v any, path string) (TResult, error) {
+	return AccessStructByStringPath[TResult](v, path, AccessStructOpt{})
+}
+
+func AccessStructByArrayPath[TResult any](v any, path []string, opts ...AccessStructOpt) (TResult, error) {
+	opt := AccessStructOpt{}
+	if len(opts) > 0 {
+		opt = opts[0]
+	}
+
+	resultVal, err := accessStructByPath(reflect.ValueOf(v), path, opt)
+	if err != nil {
+		return *new(TResult), err
+	}
+
+	if resultValCast, ok := resultVal.(TResult); ok {
+		return resultValCast, nil
+	} else if opt.ReturnNilOnWrongFinalFieldType {
+		return *new(TResult), nil
+	} else {
+		return *new(TResult), ErrAccessStructInvalidFieldType
+	}
+}
+
+func AccessStructByStringPath[TResult any](v any, path string, opts ...AccessStructOpt) (TResult, error) {
+	opt := AccessStructOpt{}
+	if len(opts) > 0 {
+		opt = opts[0]
+	}
+	arrpath := strings.Split(path, ".")
+
+	resultVal, err := accessStructByPath(reflect.ValueOf(v), arrpath, opt)
+	if err != nil {
+		return *new(TResult), err
+	}
+
+	if resultValCast, ok := resultVal.(TResult); ok {
+		return resultValCast, nil
+	} else if opt.ReturnNilOnWrongFinalFieldType {
+		return *new(TResult), nil
+	} else {
+		return *new(TResult), ErrAccessStructInvalidFieldType
+	}
+}
+
+func accessStructByPath(val reflect.Value, path []string, opt AccessStructOpt) (any, error) {
+	if len(path) == 0 {
+		return val.Interface(), nil
+	}
+
+	currPath := path[0]
+
+	if val.Kind() == reflect.Ptr {
+		if val.IsNil() {
+			if opt.ReturnNilOnNilPtrFields {
+				return nil, nil
+			} else {
+				return nil, ErrAccessStructFieldInPathWasNil
+			}
+		}
+		return accessStructByPath(val.Elem(), path, opt)
+	}
+
+	if val.Kind() == reflect.Array || val.Kind() == reflect.Slice {
+		if opt.PreventArrayAccess {
+			return nil, ErrAccessStructArrayAccess
+		}
+
+		if val.IsNil() {
+			if opt.ReturnNilOnNilPtrFields {
+				return nil, nil
+			} else {
+				return nil, ErrAccessStructFieldInPathWasNil
+			}
+		}
+
+		arrIdx, err := strconv.ParseInt(currPath, 10, 64)
+		if err != nil {
+			if opt.ReturnNilOnInvalidArrayIndizes {
+				return nil, nil
+			} else {
+				return nil, ErrAccessStructInvalidArrayIndex
+			}
+		}
+		if arrIdx < 0 || int(arrIdx) >= val.Len() {
+			if opt.ReturnNilOnInvalidArrayIndizes {
+				return nil, nil
+			} else {
+				return nil, ErrAccessStructInvalidArrayIndex
+			}
+		}
+		return accessStructByPath(val.Index(int(arrIdx)), path[1:], opt)
+	}
+
+	if val.Kind() == reflect.Map {
+		if opt.PreventMapAccess {
+			return nil, ErrAccessStructMapAccess
+		}
+
+		if val.IsNil() {
+			if opt.ReturnNilOnNilPtrFields {
+				return nil, nil
+			} else {
+				return nil, ErrAccessStructFieldInPathWasNil
+			}
+		}
+
+		mapval := val.MapIndex(reflect.ValueOf(currPath))
+		if !mapval.IsValid() || mapval.IsZero() {
+			if opt.ReturnNilOnMissingMapKeys {
+				return nil, nil
+			} else {
+				return nil, ErrAccessStructInvalidMapKey
+			}
+		}
+
+		return accessStructByPath(mapval, path[1:], opt)
+	}
+
+	if val.Kind() == reflect.Struct {
+		if opt.UsedTagForKeys != nil {
+			for i := 0; i < val.NumField(); i++ {
+				if val.Type().Field(i).Tag.Get(*opt.UsedTagForKeys) == currPath {
+					return accessStructByPath(val.Field(i), path[1:], opt)
+				}
+			}
+			if opt.ReturnNilOnMissingFields {
+				return nil, nil
+			} else {
+				return nil, ErrAccessStructMissingField
+			}
+		} else {
+			for i := 0; i < val.NumField(); i++ {
+				if val.Type().Field(i).Name == currPath {
+					return accessStructByPath(val.Field(i), path[1:], opt)
+				}
+			}
+			if opt.ReturnNilOnMissingFields {
+				return nil, nil
+			} else {
+				return nil, ErrAccessStructMissingField
+			}
+		}
+	}
+
+	if opt.ReturnNilOnWrongIntermedFieldType {
+		return nil, nil
+	} else {
+		return nil, ErrAccessStructMissingField
+	}
+}

reflectext/structAccess_test.go

@@ -0,0 +1,259 @@
+package reflectext
+
+import "testing"
+
+type TestStruct struct {
+	Name string `json:"name"`
+	Age  int    `json:"age"`
+}
+
+func TestAccessStructByArrayPath_HappyPath(t *testing.T) {
+	testStruct := TestStruct{Name: "John", Age: 30}
+	result, err := AccessStructByArrayPath[string](testStruct, []string{"Name"})
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+	if result != "John" {
+		t.Errorf("Expected 'John', got '%s'", result)
+	}
+}
+
+func TestAccessStructByArrayPath_InvalidField(t *testing.T) {
+	testStruct := TestStruct{Name: "John", Age: 30}
+	_, err := AccessStructByArrayPath[string](testStruct, []string{"Invalid"})
+	if err == nil {
+		t.Errorf("Expected error, got nil")
+	}
+}
+
+func TestAccessStructByStringPath_HappyPath(t *testing.T) {
+	testStruct := TestStruct{Name: "John", Age: 30}
+	result, err := AccessStructByStringPath[string](testStruct, "Name")
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+	if result != "John" {
+		t.Errorf("Expected 'John', got '%s'", result)
+	}
+}
+
+func TestAccessStructByStringPath_InvalidField(t *testing.T) {
+	testStruct := TestStruct{Name: "John", Age: 30}
+	_, err := AccessStructByStringPath[string](testStruct, "Invalid")
+	if err == nil {
+		t.Errorf("Expected error, got nil")
+	}
+}
+
+type RecursiveStruct struct {
+	Name     string
+	Sub      *RecursiveStruct
+	SubSlice []RecursiveStruct
+}
+
+func TestAccessStructByArrayPath_RecursiveStruct(t *testing.T) {
+	testStruct := RecursiveStruct{Name: "John", Sub: &RecursiveStruct{Name: "Jane"}}
+	result, err := AccessStructByArrayPath[string](*testStruct.Sub, []string{"Name"})
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+	if result != "Jane" {
+		t.Errorf("Expected 'Jane', got '%s'", result)
+	}
+}
+
+func TestAccessStructByArrayPath_RecursiveStructSlice(t *testing.T) {
+	testStruct := RecursiveStruct{Name: "John", SubSlice: []RecursiveStruct{{Name: "Jane"}}}
+	result, err := AccessStructByArrayPath[string](testStruct.SubSlice[0], []string{"Name"})
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+	if result != "Jane" {
+		t.Errorf("Expected 'Jane', got '%s'", result)
+	}
+}
+
+func TestAccessStructByArrayPath_WrongType(t *testing.T) {
+	testStruct := TestStruct{Name: "John", Age: 30}
+	_, err := AccessStructByArrayPath[int](testStruct, []string{"Name"})
+	if err == nil {
+		t.Errorf("Expected error, got nil")
+	}
+}
+
+func TestAccessStructByArrayPath_InvalidPath(t *testing.T) {
+	testStruct := TestStruct{Name: "John", Age: 30}
+	_, err := AccessStructByArrayPath[string](testStruct, []string{"Name", "Invalid"})
+	if err == nil {
+		t.Errorf("Expected error, got nil")
+	}
+}
+
+type NestedStruct struct {
+	Name string
+	Sub  *TestStruct
+}
+
+func TestAccessStructByStringPath_NestedStruct(t *testing.T) {
+	testStruct := NestedStruct{Name: "John", Sub: &TestStruct{Name: "Jane", Age: 30}}
+	result, err := AccessStructByStringPath[string](testStruct, "Sub.Name")
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+	if result != "Jane" {
+		t.Errorf("Expected 'Jane', got '%s'", result)
+	}
+}
+
+type DeepNestedStruct struct {
+	Name string
+	Sub  *NestedStruct
+}
+
+func TestAccessStructByStringPath_DeepNestedStruct(t *testing.T) {
+	testStruct := DeepNestedStruct{Name: "John", Sub: &NestedStruct{Name: "Jane", Sub: &TestStruct{Name: "Doe", Age: 30}}}
+	result, err := AccessStructByStringPath[string](testStruct, "Sub.Sub.Name")
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+	if result != "Doe" {
+		t.Errorf("Expected 'Doe', got '%s'", result)
+	}
+}
+
+type MapStruct struct {
+	Name string
+	Age  int
+}
+
+type TestStructWithMap struct {
+	MapField map[string]MapStruct
+}
+
+func TestAccessStructByArrayPath_MapField(t *testing.T) {
+	testStruct := TestStructWithMap{
+		MapField: map[string]MapStruct{
+			"key": {Name: "John", Age: 30},
+		},
+	}
+	result, err := AccessStructByArrayPath[string](testStruct, []string{"MapField", "key", "Name"})
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+	if result != "John" {
+		t.Errorf("Expected 'John', got '%s'", result)
+	}
+}
+
+func TestAccessStructByArrayPath_InvalidMapKey(t *testing.T) {
+	testStruct := TestStructWithMap{
+		MapField: map[string]MapStruct{
+			"key": {Name: "John", Age: 30},
+		},
+	}
+	_, err := AccessStructByArrayPath[string](testStruct, []string{"MapField", "invalid", "Name"})
+	if err == nil {
+		t.Errorf("Expected error, got nil")
+	}
+}
+
+type ArrayStruct struct {
+	Name string
+	Arr  []TestStruct
+}
+
+func TestAccessStructByArrayPath_ArrayField(t *testing.T) {
+	testStruct := ArrayStruct{
+		Name: "John",
+		Arr:  []TestStruct{{Name: "Jane", Age: 30}},
+	}
+	result, err := AccessStructByArrayPath[string](testStruct, []string{"Arr", "0", "Name"})
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+	if result != "Jane" {
+		t.Errorf("Expected 'Jane', got '%s'", result)
+	}
+}
+
+func TestAccessStructByArrayPath_InvalidArrayIndex(t *testing.T) {
+	testStruct := ArrayStruct{
+		Name: "John",
+		Arr:  []TestStruct{{Name: "Jane", Age: 30}},
+	}
+	_, err := AccessStructByArrayPath[string](testStruct, []string{"Arr", "1", "Name"})
+	if err == nil {
+		t.Errorf("Expected error, got nil")
+	}
+}
+
+type FunctionStruct struct {
+	Name string
+	Func func() string
+}
+
+func TestAccessStructByArrayPath_FunctionField(t *testing.T) {
+	testStruct := FunctionStruct{Name: "John", Func: func() string { return "Hello" }}
+	_, err := AccessStructByArrayPath[string](testStruct, []string{"Func"})
+	if err == nil {
+		t.Errorf("Expected error, got nil")
+	}
+}
+
+func TestAccessStructByArrayPath_NonExistentPath(t *testing.T) {
+	testStruct := TestStruct{Name: "John", Age: 30}
+	_, err := AccessStructByArrayPath[string](testStruct, []string{"NonExistent"})
+	if err == nil {
+		t.Errorf("Expected error, got nil")
+	}
+}
+
+type NestedStructWithTag struct {
+	Name string      `json:"name"`
+	Sub  *TestStruct `json:"sub"`
+}
+
+func TestAccessStructByArrayPath_UsedTagForKeys(t *testing.T) {
+	testStruct := NestedStructWithTag{Name: "John", Sub: &TestStruct{Name: "Jane", Age: 30}}
+	tag := "json"
+	result, err := AccessStructByArrayPath[string](testStruct, []string{"sub", "name"}, AccessStructOpt{UsedTagForKeys: &tag})
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+	if result != "Jane" {
+		t.Errorf("Expected 'Jane', got '%s'", result)
+	}
+}
+
+func TestAccessStructByArrayPath_UsedTagForKeysInvalid(t *testing.T) {
+	testStruct := NestedStructWithTag{Name: "John", Sub: &TestStruct{Name: "Jane", Age: 30}}
+	tag := "json"
+	_, err := AccessStructByArrayPath[string](testStruct, []string{"sub", "invalid"}, AccessStructOpt{UsedTagForKeys: &tag})
+	if err == nil {
+		t.Errorf("Expected error, got nil")
+	}
+}
+
+type DifferentTypeStruct struct {
+	Name string
+	Age  int
+}
+
+func TestAccessStructByArrayPath_DifferentType(t *testing.T) {
+	testStruct := DifferentTypeStruct{Name: "John", Age: 30}
+	result, err := AccessStructByArrayPath[any](testStruct, []string{"Age"})
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+	if result != 30 {
+		t.Errorf("Expected '30', got '%v'", result)
+	}
+}
+
+func TestAccessStructByArrayPath_DifferentTypeInvalid(t *testing.T) {
+	testStruct := DifferentTypeStruct{Name: "John", Age: 30}
+	_, err := AccessStructByArrayPath[any](testStruct, []string{"Invalid"})
+	if err == nil {
+		t.Errorf("Expected error, got nil")
+	}
+}

timeext/diff.go

@@ -0,0 +1,13 @@
+package timeext
+
+import "time"
+
+func YearDifference(t1 time.Time, t2 time.Time, tz *time.Location) float64 {
+
+	yDelta := float64(t1.Year() - t2.Year())
+
+	processT1 := float64(t1.Sub(TimeToYearStart(t1, tz))) / float64(TimeToYearEnd(t1, tz).Sub(TimeToYearStart(t1, tz)))
+	processT2 := float64(t2.Sub(TimeToYearStart(t2, tz))) / float64(TimeToYearEnd(t2, tz).Sub(TimeToYearStart(t2, tz)))
+
+	return yDelta + (processT1 - processT2)
+}

timeext/diff_test.go

@@ -0,0 +1,83 @@
+package timeext
+
+import (
+	"math"
+	"testing"
+	"time"
+)
+
+func TestYearDifferenceWithSameYearAndDay(t *testing.T) {
+	t1 := time.Date(2020, 1, 1, 0, 0, 0, 0, time.UTC)
+	t2 := time.Date(2020, 1, 1, 0, 0, 0, 0, time.UTC)
+	expected := 0.0
+	result := YearDifference(t1, t2, time.UTC)
+	if !epsilonEquals(result, expected) {
+		t.Errorf("Expected %v, got %v", expected, result)
+	}
+}
+
+func TestYearDifferenceWithOneYearApart(t *testing.T) {
+	t1 := time.Date(2021, 1, 1, 0, 0, 0, 0, time.UTC)
+	t2 := time.Date(2020, 1, 1, 0, 0, 0, 0, time.UTC)
+	expected := 1.0
+	result := YearDifference(t1, t2, time.UTC)
+	if !epsilonEquals(result, expected) {
+		t.Errorf("Expected %v, got %v", expected, result)
+	}
+}
+
+func TestYearDifferenceWithDifferentMonths(t *testing.T) {
+	t1 := time.Date(2020, 6, 1, 0, 0, 0, 0, time.UTC)
+	t2 := time.Date(2020, 1, 1, 0, 0, 0, 0, time.UTC)
+	expected := 0.4166666666666667 // Approximation of 5/12 months
+	result := YearDifference(t1, t2, time.UTC)
+	if !epsilonEquals(result, expected) {
+		t.Errorf("Expected %v, got %v", expected, result)
+	}
+}
+
+func TestYearDifferenceAcrossYears(t *testing.T) {
+	t1 := time.Date(2021, 1, 1, 0, 0, 0, 0, time.UTC)
+	t2 := time.Date(2020, 6, 1, 0, 0, 0, 0, time.UTC)
+	expected := 0.5833333333333334 // Approximation of 7/12 months
+	result := YearDifference(t1, t2, time.UTC)
+	if !epsilonEquals(result, expected) {
+		t.Errorf("Expected %v, got %v", expected, result)
+	}
+}
+
+func TestYearDifferenceWithTimezone(t *testing.T) {
+	tz, _ := time.LoadLocation("America/New_York")
+	t1 := time.Date(2021, 1, 1, 0, 0, 0, 0, tz)
+	t2 := time.Date(2020, 6, 1, 0, 0, 0, 0, tz)
+	expected := 0.5833333333333334 // Same as UTC but ensuring timezone is considered
+	result := YearDifference(t1, t2, tz)
+	if !epsilonEquals(result, expected) {
+		t.Errorf("Expected %v, got %v", expected, result)
+	}
+}
+
+func TestYearDifferenceWithNegativeDifference(t *testing.T) {
+	t1 := time.Date(2020, 1, 1, 0, 0, 0, 0, TimezoneBerlin)
+	t2 := time.Date(2021, 1, 1, 0, 0, 0, 0, TimezoneBerlin)
+	expected := -1.0
+	result := YearDifference(t1, t2, TimezoneBerlin)
+	if !epsilonEquals(result, expected) {
+		t.Errorf("Expected %v, got %v", expected, result)
+	}
+}
+
+func TestYearDifferenceWithNegativeDifference2(t *testing.T) {
+	t1 := time.Date(2020, 7, 1, 0, 0, 0, 0, TimezoneBerlin)
+	t2 := time.Date(2021, 7, 1, 0, 0, 0, 0, TimezoneBerlin)
+	expected := -1.0
+	result := YearDifference(t1, t2, TimezoneBerlin)
+	if !epsilonEquals(result, expected) {
+		t.Errorf("Expected %v, got %v", expected, result)
+	}
+}
+
+func epsilonEquals(a, b float64) bool {
+	epsilon := 0.01
+	return math.Abs(a-b) < epsilon
+}

timeext/time.go

@@ -65,6 +65,10 @@ func TimeToYearEnd(t time.Time, tz *time.Location) time.Time {
 	return TimeToYearStart(t, tz).AddDate(1, 0, 0).Add(-1)
 }
 
+func TimeToNextYearStart(t time.Time, tz *time.Location) time.Time {
+	return TimeToYearStart(t, tz).AddDate(1, 0, 0)
+}
+
 // IsSameDayIncludingDateBoundaries returns true if t1 and t2 are part of the same day (TZ/Berlin), the boundaries of the day are
 // inclusive, this means 2021-09-15T00:00:00 is still part of the day 2021-09-14
 func IsSameDayIncludingDateBoundaries(t1 time.Time, t2 time.Time, tz *time.Location) bool {

timeext/time_test.go

@@ -72,6 +72,13 @@ func TestIsSunday(t *testing.T) {
 	}
 }
 
+func TestIsSunday_OnSunday(t *testing.T) {
+	sunday := time.Date(2022, 5, 15, 0, 0, 0, 0, TimezoneBerlin) // A Sunday
+	if !IsSunday(sunday, TimezoneBerlin) {
+		t.Errorf("Expected true for Sunday")
+	}
+}
+
 func TestDurationFromTime(t *testing.T) {
 	expected := time.Duration(13*time.Hour + 14*time.Minute + 15*time.Second)
 	result := DurationFromTime(13, 14, 15)
@@ -156,3 +163,31 @@ func TestAddYears(t *testing.T) {
 		t.Errorf("Expected %v but got %v", expected, result)
 	}
 }
+
+func TestIsDatePartEqual_SameDateDifferentTimes(t *testing.T) {
+	tz := time.UTC
+	t1 := time.Date(2022, 5, 18, 10, 30, 0, 0, tz)
+	t2 := time.Date(2022, 5, 18, 20, 45, 0, 0, tz)
+	if !IsDatePartEqual(t1, t2, tz) {
+		t.Errorf("Expected dates to be equal")
+	}
+}
+
+func TestWithTimePart_ChangeTime(t *testing.T) {
+	base := time.Date(2022, 5, 18, 0, 0, 0, 0, time.UTC)
+	result := WithTimePart(base, 15, 30, 45)
+	expected := time.Date(2022, 5, 18, 15, 30, 45, 0, time.UTC)
+	if !result.Equal(expected) {
+		t.Errorf("Expected %v, got %v", expected, result)
+	}
+}
+
+func TestCombineDateAndTime_CombineDifferentParts(t *testing.T) {
+	date := time.Date(2022, 5, 18, 0, 0, 0, 0, time.UTC)
+	timePart := time.Date(2000, 1, 1, 15, 30, 45, 0, time.UTC)
+	result := CombineDateAndTime(date, timePart)
+	expected := time.Date(2022, 5, 18, 15, 30, 45, 0, time.UTC)
+	if !result.Equal(expected) {
+		t.Errorf("Expected %v, got %v", expected, result)
+	}
+}