feat: adding CoalesceMap

README.md

@@ -272,6 +272,10 @@ Type manipulation helpers:
 - [IsNotEmpty](#isnotempty)
 - [Coalesce](#coalesce)
 - [CoalesceOrEmpty](#coalesceorempty)
+- [CoalesceSlice](#coalesceslice)
+- [CoalesceSliceOrEmpty](#coalescesliceorempty)
+- [CoalesceMap](#coalescemap)
+- [CoalesceMapOrEmpty](#coalescemaporempty)
 
 Function helpers:
 
@@ -3011,6 +3015,58 @@ result := lo.CoalesceOrEmpty(nil, nilStr, &str)
 // &"foobar"
 ```
 
+### CoalesceSlice
+
+Returns the first non-zero slice.
+
+```go
+result, ok := lo.CoalesceSlice([]int{1, 2, 3}, []int{4, 5, 6})
+// [1, 2, 3]
+// true
+
+result, ok := lo.CoalesceSlice(nil, []int{})
+// []
+// true
+```
+
+### CoalesceSliceOrEmpty
+
+Returns the first non-zero slice.
+
+```go
+result := lo.CoalesceSliceOrEmpty([]int{1, 2, 3}, []int{4, 5, 6})
+// [1, 2, 3]
+
+result := lo.CoalesceSliceOrEmpty(nil, []int{})
+// []
+```
+
+### CoalesceMap
+
+Returns the first non-zero map.
+
+```go
+result, ok := lo.CoalesceMap(map[string]int{"1": 1, "2": 2, "3": 3}, map[string]int{"4": 4, "5": 5, "6": 6})
+// [1, 2, 3]
+// true
+
+result, ok := lo.CoalesceMap(nil, map[string]int{})
+// []
+// true
+```
+
+### CoalesceMapOrEmpty
+
+Returns the first non-zero map.
+
+```go
+result := lo.CoalesceMapOrEmpty(map[string]int{"1": 1, "2": 2, "3": 3}, map[string]int{"4": 4, "5": 5, "6": 6})
+// {"1": 1, "2": 2, "3": 3}
+
+result := lo.CoalesceMapOrEmpty(nil, map[string]int{})
+// {}
+```
+
 ### Partial
 
 Returns new function that, when called, has its first argument set to the provided value.

type_manipulation.go

@@ -143,8 +143,18 @@ func CoalesceOrEmpty[T comparable](v ...T) T {
 	return result
 }
 
-// CoalesceOrEmptySlice returns the first non-zero slice.
-func CoalesceOrEmptySlice[T any](v ...[]T) []T {
+// CoalesceSlice returns the first non-zero slice.
+func CoalesceSlice[T any](v ...[]T) ([]T, bool) {
+	for i := range v {
+		if v[i] != nil && len(v[i]) > 0 {
+			return v[i], true
+		}
+	}
+	return []T{}, false
+}
+
+// CoalesceSliceOrEmpty returns the first non-zero slice.
+func CoalesceSliceOrEmpty[T any](v ...[]T) []T {
 	for i := range v {
 		if v[i] != nil && len(v[i]) > 0 {
 			return v[i]
@@ -152,3 +162,23 @@ func CoalesceOrEmptySlice[T any](v ...[]T) []T {
 	}
 	return []T{}
 }
+
+// CoalesceMap returns the first non-zero map.
+func CoalesceMap[K comparable, V any](v ...map[K]V) (map[K]V, bool) {
+	for i := range v {
+		if v[i] != nil && len(v[i]) > 0 {
+			return v[i], true
+		}
+	}
+	return map[K]V{}, false
+}
+
+// CoalesceMapOrEmpty returns the first non-zero map.
+func CoalesceMapOrEmpty[K comparable, V any](v ...map[K]V) map[K]V {
+	for i := range v {
+		if v[i] != nil && len(v[i]) > 0 {
+			return v[i]
+		}
+	}
+	return map[K]V{}
+}

type_manipulation_test.go

@@ -317,7 +317,7 @@ func TestCoalesceOrEmpty(t *testing.T) {
 	is.Equal(result10, struct1)
 }
 
-func TestCoalesceOrEmptySlice(t *testing.T) {
+func TestCoalesceSlice(t *testing.T) {
 	t.Parallel()
 	is := assert.New(t)
 
@@ -326,16 +326,82 @@ func TestCoalesceOrEmptySlice(t *testing.T) {
 	slice1 := []int{1}
 	slice2 := []int{1, 2}
 
-	result1 := CoalesceOrEmptySlice[int]()
-	result2 := CoalesceOrEmptySlice[int](nil)
-	result3 := CoalesceOrEmptySlice(sliceNil)
-	result4 := CoalesceOrEmptySlice(slice0)
-	result5 := CoalesceOrEmptySlice(nil, sliceNil, slice0)
-	result6 := CoalesceOrEmptySlice(slice2)
-	result7 := CoalesceOrEmptySlice(slice1)
-	result8 := CoalesceOrEmptySlice(slice1, slice2)
-	result9 := CoalesceOrEmptySlice(slice2, slice1)
-	result10 := CoalesceOrEmptySlice(sliceNil, slice0, slice1, slice2)
+	result1, ok1 := CoalesceSlice[int]()
+	result2, ok2 := CoalesceSlice[int](nil)
+	result3, ok3 := CoalesceSlice(sliceNil)
+	result4, ok4 := CoalesceSlice(slice0)
+	result5, ok5 := CoalesceSlice(nil, sliceNil, slice0)
+	result6, ok6 := CoalesceSlice(slice2)
+	result7, ok7 := CoalesceSlice(slice1)
+	result8, ok8 := CoalesceSlice(slice1, slice2)
+	result9, ok9 := CoalesceSlice(slice2, slice1)
+	result10, ok10 := CoalesceSlice(sliceNil, slice0, slice1, slice2)
+
+	is.NotNil(result1)
+	is.Empty(result1)
+	is.Equal([]int{}, result1)
+	is.False(ok1)
+
+	is.NotNil(result2)
+	is.Empty(result2)
+	is.Equal([]int{}, result2)
+	is.False(ok2)
+
+	is.NotNil(result3)
+	is.Empty(result3)
+	is.Equal([]int{}, result3)
+	is.False(ok3)
+
+	is.NotNil(result4)
+	is.Empty(result4)
+	is.Equal([]int{}, result4)
+	is.False(ok4)
+
+	is.NotNil(result5)
+	is.Empty(result5)
+	is.Equal([]int{}, result5)
+	is.False(ok5)
+
+	is.NotNil(result6)
+	is.Equal(slice2, result6)
+	is.True(ok6)
+
+	is.NotNil(result7)
+	is.Equal(slice1, result7)
+	is.True(ok7)
+
+	is.NotNil(result8)
+	is.Equal(slice1, result8)
+	is.True(ok8)
+
+	is.NotNil(result9)
+	is.Equal(slice2, result9)
+	is.True(ok9)
+
+	is.NotNil(result10)
+	is.Equal(slice1, result10)
+	is.True(ok10)
+}
+
+func TestCoalesceSliceOrEmpty(t *testing.T) {
+	t.Parallel()
+	is := assert.New(t)
+
+	var sliceNil []int
+	slice0 := []int{}
+	slice1 := []int{1}
+	slice2 := []int{1, 2}
+
+	result1 := CoalesceSliceOrEmpty[int]()
+	result2 := CoalesceSliceOrEmpty[int](nil)
+	result3 := CoalesceSliceOrEmpty(sliceNil)
+	result4 := CoalesceSliceOrEmpty(slice0)
+	result5 := CoalesceSliceOrEmpty(nil, sliceNil, slice0)
+	result6 := CoalesceSliceOrEmpty(slice2)
+	result7 := CoalesceSliceOrEmpty(slice1)
+	result8 := CoalesceSliceOrEmpty(slice1, slice2)
+	result9 := CoalesceSliceOrEmpty(slice2, slice1)
+	result10 := CoalesceSliceOrEmpty(sliceNil, slice0, slice1, slice2)
 
 	is.NotNil(result1)
 	is.Empty(result1)
@@ -363,3 +429,116 @@ func TestCoalesceOrEmptySlice(t *testing.T) {
 	is.NotNil(result10)
 	is.Equal(slice1, result10)
 }
+
+func TestCoalesceMap(t *testing.T) {
+	t.Parallel()
+	is := assert.New(t)
+
+	var mapNil map[int]int
+	map0 := map[int]int{}
+	map1 := map[int]int{1: 1}
+	map2 := map[int]int{1: 1, 2: 2}
+
+	result1, ok1 := CoalesceMap[int, int]()
+	result2, ok2 := CoalesceMap[int, int](nil)
+	result3, ok3 := CoalesceMap(mapNil)
+	result4, ok4 := CoalesceMap(map0)
+	result5, ok5 := CoalesceMap(nil, mapNil, map0)
+	result6, ok6 := CoalesceMap(map2)
+	result7, ok7 := CoalesceMap(map1)
+	result8, ok8 := CoalesceMap(map1, map2)
+	result9, ok9 := CoalesceMap(map2, map1)
+	result10, ok10 := CoalesceMap(mapNil, map0, map1, map2)
+
+	is.NotNil(result1)
+	is.Empty(result1)
+	is.Equal(map[int]int{}, result1)
+	is.False(ok1)
+
+	is.NotNil(result2)
+	is.Empty(result2)
+	is.Equal(map[int]int{}, result2)
+	is.False(ok2)
+
+	is.NotNil(result3)
+	is.Empty(result3)
+	is.Equal(map[int]int{}, result3)
+	is.False(ok3)
+
+	is.NotNil(result4)
+	is.Empty(result4)
+	is.Equal(map[int]int{}, result4)
+	is.False(ok4)
+
+	is.NotNil(result5)
+	is.Empty(result5)
+	is.Equal(map[int]int{}, result5)
+	is.False(ok5)
+
+	is.NotNil(result6)
+	is.Equal(map2, result6)
+	is.True(ok6)
+
+	is.NotNil(result7)
+	is.Equal(map1, result7)
+	is.True(ok7)
+
+	is.NotNil(result8)
+	is.Equal(map1, result8)
+	is.True(ok8)
+
+	is.NotNil(result9)
+	is.Equal(map2, result9)
+	is.True(ok9)
+
+	is.NotNil(result10)
+	is.Equal(map1, result10)
+	is.True(ok10)
+}
+
+func TestCoalesceMapOrEmpty(t *testing.T) {
+	t.Parallel()
+	is := assert.New(t)
+
+	var mapNil map[int]int
+	map0 := map[int]int{}
+	map1 := map[int]int{1: 1}
+	map2 := map[int]int{1: 1, 2: 2}
+
+	result1 := CoalesceMapOrEmpty[int, int]()
+	result2 := CoalesceMapOrEmpty[int, int](nil)
+	result3 := CoalesceMapOrEmpty(mapNil)
+	result4 := CoalesceMapOrEmpty(map0)
+	result5 := CoalesceMapOrEmpty(nil, mapNil, map0)
+	result6 := CoalesceMapOrEmpty(map2)
+	result7 := CoalesceMapOrEmpty(map1)
+	result8 := CoalesceMapOrEmpty(map1, map2)
+	result9 := CoalesceMapOrEmpty(map2, map1)
+	result10 := CoalesceMapOrEmpty(mapNil, map0, map1, map2)
+
+	is.NotNil(result1)
+	is.Empty(result1)
+	is.Equal(map[int]int{}, result1)
+	is.NotNil(result2)
+	is.Empty(result2)
+	is.Equal(map[int]int{}, result2)
+	is.NotNil(result3)
+	is.Empty(result3)
+	is.Equal(map[int]int{}, result3)
+	is.NotNil(result4)
+	is.Empty(result4)
+	is.Equal(map[int]int{}, result4)
+	is.NotNil(result5)
+	is.Empty(result5)
+	is.Equal(map[int]int{}, result5)
+	is.NotNil(result6)
+	is.Equal(map2, result6)
+	is.NotNil(result7)
+	is.Equal(map1, result7)
+	is.NotNil(result8)
+	is.Equal(map1, result8)
+	is.NotNil(result9)
+	is.Equal(map2, result9)
+	is.NotNil(result10)
+	is.Equal(map1, result10)
+}