chore: test coverage improvement (#240)

* chore: improves channel functions test coverage

* chore: improves errors functions test coverage

* chore: improves map functions test coverage

* chore: improves parallel slice functions test coverage

* chore: improves slice functions test coverage

* fix: uses atomic counter on parallel/slice_test

* Update channel_test.go

Co-authored-by: Samuel Berthe <dev@samuel-berthe.fr>

channel_test.go

@@ -1,6 +1,7 @@
 package lo
 
 import (
+	"math/rand"
 	"testing"
 	"time"
 
@@ -111,7 +112,21 @@ func TestDispatchingStrategyRoundRobin(t *testing.T) {
 }
 
 func TestDispatchingStrategyRandom(t *testing.T) {
-	// @TODO
+	testWithTimeout(t, 10*time.Millisecond)
+	is := assert.New(t)
+
+	// with this seed, the order of random channels are: 1 - 0
+	rand.Seed(14)
+
+	children := createChannels[int](2, 2)
+	rochildren := channelsToReadOnly(children)
+	defer closeChannels(children)
+
+	for i := 0; i < 2; i++ {
+		children[1] <- i
+	}
+
+	is.Equal(0, DispatchingStrategyRandom[int](42, 0, rochildren))
 }
 
 func TestDispatchingStrategyWeightedRandom(t *testing.T) {

errors_test.go

@@ -53,6 +53,13 @@ func TestMust(t *testing.T) {
 	is.PanicsWithValue("operation should fail: assert.AnError general error for testing", func() {
 		Must0(cb(), "operation should fail")
 	})
+
+	is.PanicsWithValue("must: invalid err type 'int', should either be a bool or an error", func() {
+		Must0(0)
+	})
+	is.PanicsWithValue("must: invalid err type 'string', should either be a bool or an error", func() {
+		Must0("error")
+	})
 }
 
 func TestMustX(t *testing.T) {
@@ -264,7 +271,11 @@ func TestTry(t *testing.T) {
 func TestTryX(t *testing.T) {
 	t.Parallel()
 	is := assert.New(t)
-
+
+	is.True(Try1(func() error {
+		return nil
+	}))
+
 	is.True(Try2(func() (string, error) {
 		return "", nil
 	}))
@@ -284,7 +295,11 @@ func TestTryX(t *testing.T) {
 	is.True(Try6(func() (string, string, string, string, string, error) {
 		return "", "", "", "", "", nil
 	}))
-
+
+	is.False(Try1(func() error {
+		panic("error")
+	}))
+
 	is.False(Try2(func() (string, error) {
 		panic("error")
 	}))
@@ -304,7 +319,11 @@ func TestTryX(t *testing.T) {
 	is.False(Try6(func() (string, string, string, string, string, error) {
 		panic("error")
 	}))
-
+
+	is.False(Try1(func() error {
+		return errors.New("foo")
+	}))
+
 	is.False(Try2(func() (string, error) {
 		return "", errors.New("foo")
 	}))
@@ -489,11 +508,18 @@ func TestTryWithErrorValue(t *testing.T) {
 	is := assert.New(t)
 
 	err, ok := TryWithErrorValue(func() error {
+		// getting error in case of panic, using recover function
 		panic("error")
 	})
 	is.False(ok)
 	is.Equal("error", err)
-
+
+	err, ok = TryWithErrorValue(func() error {
+		return errors.New("foo")
+	})
+	is.False(ok)
+	is.EqualError(err.(error), "foo")
+
 	err, ok = TryWithErrorValue(func() error {
 		return nil
 	})

map_test.go

@@ -108,10 +108,31 @@ func TestEntries(t *testing.T) {
 	})
 }
 
-func TestFromEntries(t *testing.T) {
+func TestToPairs(t *testing.T) {
 	t.Parallel()
 	is := assert.New(t)
+
+	r1 := ToPairs(map[string]int{"baz": 3, "qux": 4})
+
+	sort.Slice(r1, func(i, j int) bool {
+		return r1[i].Value < r1[j].Value
+	})
+	is.EqualValues(r1, []Entry[string, int]{
+		{
+			Key:   "baz",
+			Value: 3,
+		},
+		{
+			Key:   "qux",
+			Value: 4,
+		},
+	})
+}
 
+func TestFromEntries(t *testing.T) {
+	t.Parallel()
+	is := assert.New(t)
+
 	r1 := FromEntries([]Entry[string, int]{
 		{
 			Key:   "foo",
@@ -128,10 +149,30 @@ func TestFromEntries(t *testing.T) {
 	is.Equal(r1["bar"], 2)
 }
 
-func TestInvert(t *testing.T) {
+func TestFromPairs(t *testing.T) {
 	t.Parallel()
 	is := assert.New(t)
+
+	r1 := FromPairs([]Entry[string, int]{
+		{
+			Key:   "baz",
+			Value: 3,
+		},
+		{
+			Key:   "qux",
+			Value: 4,
+		},
+	})
+
+	is.Len(r1, 2)
+	is.Equal(r1["baz"], 3)
+	is.Equal(r1["qux"], 4)
+}
 
+func TestInvert(t *testing.T) {
+	t.Parallel()
+	is := assert.New(t)
+
 	r1 := Invert(map[string]int{"a": 1, "b": 2})
 	r2 := Invert(map[string]int{"a": 1, "b": 2, "c": 1})
 

parallel/slice_test.go

@@ -3,52 +3,65 @@ package parallel
 import (
 	"sort"
 	"strconv"
+	"sync/atomic"
 	"testing"
-
+	
 	"github.com/stretchr/testify/assert"
 )
 
 func TestMap(t *testing.T) {
 	is := assert.New(t)
-
+	
 	result1 := Map([]int{1, 2, 3, 4}, func(x int, _ int) string {
 		return "Hello"
 	})
 	result2 := Map([]int64{1, 2, 3, 4}, func(x int64, _ int) string {
 		return strconv.FormatInt(x, 10)
 	})
-
+	
 	is.Equal(len(result1), 4)
 	is.Equal(len(result2), 4)
 	is.Equal(result1, []string{"Hello", "Hello", "Hello", "Hello"})
 	is.Equal(result2, []string{"1", "2", "3", "4"})
 }
 
-func TestTimes(t *testing.T) {
+func TestForEach(t *testing.T) {
 	is := assert.New(t)
+
+	var counter uint64
+	collection := []int{1, 2, 3, 4}
+	ForEach(collection, func(x int, i int) {
+		atomic.AddUint64(&counter, 1)
+	})
+
+	is.Equal(uint64(4), atomic.LoadUint64(&counter))
+}
 
+func TestTimes(t *testing.T) {
+	is := assert.New(t)
+
 	result1 := Times(3, func(i int) string {
 		return strconv.FormatInt(int64(i), 10)
 	})
-
+	
 	is.Equal(len(result1), 3)
 	is.Equal(result1, []string{"0", "1", "2"})
 }
 
 func TestGroupBy(t *testing.T) {
 	is := assert.New(t)
-
+	
 	result1 := GroupBy([]int{0, 1, 2, 3, 4, 5}, func(i int) int {
 		return i % 3
 	})
-
+	
 	// order
 	for x := range result1 {
 		sort.Slice(result1[x], func(i, j int) bool {
 			return result1[x][i] < result1[x][j]
 		})
 	}
-
+	
 	is.EqualValues(len(result1), 3)
 	is.EqualValues(result1, map[int][]int{
 		0: {0, 3},
@@ -59,7 +72,7 @@ func TestGroupBy(t *testing.T) {
 
 func TestPartitionBy(t *testing.T) {
 	is := assert.New(t)
-
+	
 	oddEven := func(x int) string {
 		if x < 0 {
 			return "negative"
@@ -68,10 +81,10 @@ func TestPartitionBy(t *testing.T) {
 		}
 		return "odd"
 	}
-
+	
 	result1 := PartitionBy([]int{-2, -1, 0, 1, 2, 3, 4, 5}, oddEven)
 	result2 := PartitionBy([]int{}, oddEven)
-
+	
 	// order
 	sort.Slice(result1, func(i, j int) bool {
 		return result1[i][0] < result1[j][0]
@@ -81,7 +94,7 @@ func TestPartitionBy(t *testing.T) {
 			return result1[x][i] < result1[x][j]
 		})
 	}
-
+	
 	is.ElementsMatch(result1, [][]int{{-2, -1}, {0, 2, 4}, {1, 3, 5}})
 	is.Equal(result2, [][]int{})
 }

slice_test.go

@@ -197,6 +197,9 @@ func TestChunk(t *testing.T) {
 	is.Equal(result2, [][]int{{0, 1}, {2, 3}, {4, 5}, {6}})
 	is.Equal(result3, [][]int{})
 	is.Equal(result4, [][]int{{0}})
+	is.PanicsWithValue("Second parameter must be greater than 0", func() {
+		Chunk([]int{0}, 0)
+	})
 }
 
 func TestPartitionBy(t *testing.T) {
@@ -383,6 +386,41 @@ func TestAssociate(t *testing.T) {
 	}
 }
 
+func TestSliceToMap(t *testing.T) {
+	t.Parallel()
+
+	type foo struct {
+		baz string
+		bar int
+	}
+	transform := func(f *foo) (string, int) {
+		return f.baz, f.bar
+	}
+	testCases := []struct {
+		in     []*foo
+		expect map[string]int
+	}{
+		{
+			in:     []*foo{{baz: "apple", bar: 1}},
+			expect: map[string]int{"apple": 1},
+		},
+		{
+			in:     []*foo{{baz: "apple", bar: 1}, {baz: "banana", bar: 2}},
+			expect: map[string]int{"apple": 1, "banana": 2},
+		},
+		{
+			in:     []*foo{{baz: "apple", bar: 1}, {baz: "apple", bar: 2}},
+			expect: map[string]int{"apple": 2},
+		},
+	}
+	for i, testCase := range testCases {
+		t.Run(fmt.Sprintf("test_%d", i), func(t *testing.T) {
+			is := assert.New(t)
+			is.Equal(SliceToMap(testCase.in, transform), testCase.expect)
+		})
+	}
+}
+
 func TestDrop(t *testing.T) {
 	t.Parallel()
 	is := assert.New(t)
@@ -584,7 +622,8 @@ func TestSlice(t *testing.T) {
 	out12 := Slice(in, 1, 0)
 	out13 := Slice(in, 5, 0)
 	out14 := Slice(in, 6, 4)
-
+	out15 := Slice(in, 6, 7)
+
 	is.Equal([]int{}, out1)
 	is.Equal([]int{0}, out2)
 	is.Equal([]int{0, 1, 2, 3, 4}, out3)
@@ -599,6 +638,7 @@ func TestSlice(t *testing.T) {
 	is.Equal([]int{}, out12)
 	is.Equal([]int{}, out13)
 	is.Equal([]int{}, out14)
+	is.Equal([]int{}, out15)
 }
 
 func TestReplace(t *testing.T) {