feat: add xtime.FormatDuration and xtime.ParseDuration

README.md

@@ -11,9 +11,8 @@ comes in the form of a collection of packages.
 
 ## Dependencies
 
-The packages are dependency free meaning. Packages added to this module must not
-use any external dependencies unless listed below.
-
+The packages are dependency free, meaning they must not use any external
+dependencies unless explicitly listed.
 Exceptions:
 
 - `golang.org/x/*` - maintained by go and dependency free
@@ -28,20 +27,19 @@ Do *NOT* add exceptions to this list without peer review.
 
 - Prefix names for packages that mirror a go standard library package with `x`.
 - Prefix names for packages that are likely to mirror future go standard library
-  Packages with `x`.
+  packages with `x`.
 - Use singular names for package (except in the mentioned cases).
 
 ## Testing
 
 - Unit testing is mandatory.
-- Go for > 95% coverage, preferably 100%.
+- Go for > 90% coverage, preferably 100%.
 
 ## Documentation
 
 - Document all exported (public) identifiers
 - Maintain a `doc.go` in each package with introduction, installation
   instructions and usage examples.
-- Use `make gen` to generate `README.md` files
 
 ### doc.go minimal content
 
@@ -57,11 +55,11 @@ package mypkg
 - `file` - file operations
 - `set` - set data structure
 - `unit` - unit formatting and conversion package
-- `version` - version functions
 - `xjson` - JSON functions
 - `xslices` - slice data type functions
 - `xstrings` - string data type functions
 - `xstructs` - struct data type functions
+- `xtime` - time functions
 
 ## Installation
 

xstrings/funcs.go

@@ -0,0 +1,14 @@
+package xstrings
+
+import "github.com/neticdk/go-stdlib/xslices"
+
+// Coalesce returns the first non-empty string from the given slice.
+func Coalesce(strs ...string) string {
+	s, found := xslices.FindFunc(strs, func(s string) bool {
+		return s != ""
+	})
+	if found {
+		return s
+	}
+	return ""
+}

xstrings/funcs_test.go

@@ -0,0 +1,68 @@
+package xstrings_test
+
+import (
+	"testing"
+
+	"github.com/neticdk/go-stdlib/assert"
+	"github.com/neticdk/go-stdlib/xstrings"
+)
+
+func TestCoalesce(t *testing.T) {
+	tests := []struct {
+		name string
+		args []string
+		want string
+	}{
+		{
+			name: "Empty slice",
+			args: []string{},
+			want: "",
+		},
+		{
+			name: "All empty strings",
+			args: []string{"", "", ""},
+			want: "",
+		},
+		{
+			name: "First string non-empty",
+			args: []string{"first", "second", "third"},
+			want: "first",
+		},
+		{
+			name: "Second string non-empty",
+			args: []string{"", "second", "third"},
+			want: "second",
+		},
+		{
+			name: "Last string non-empty",
+			args: []string{"", "", "third"},
+			want: "third",
+		},
+		{
+			name: "Mixed empty and non-empty",
+			args: []string{"", "second", "", "fourth"},
+			want: "second",
+		},
+		{
+			name: "Single non-empty string",
+			args: []string{"single"},
+			want: "single",
+		},
+		{
+			name: "Single empty string",
+			args: []string{""},
+			want: "",
+		},
+		{
+			name: "Nil slice (variadic converts nil to empty)",
+			args: nil,
+			want: "",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := xstrings.Coalesce(tt.args...)
+			assert.Equal(t, got, tt.want, "Coalesce()/%s", tt.name)
+		})
+	}
+}