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-rw-r--r--src/slices/slices_test.go1075
1 files changed, 1075 insertions, 0 deletions
diff --git a/src/slices/slices_test.go b/src/slices/slices_test.go
new file mode 100644
index 0000000..6984f27
--- /dev/null
+++ b/src/slices/slices_test.go
@@ -0,0 +1,1075 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package slices
+
+import (
+ "cmp"
+ "internal/race"
+ "internal/testenv"
+ "math"
+ "strings"
+ "testing"
+)
+
+var equalIntTests = []struct {
+ s1, s2 []int
+ want bool
+}{
+ {
+ []int{1},
+ nil,
+ false,
+ },
+ {
+ []int{},
+ nil,
+ true,
+ },
+ {
+ []int{1, 2, 3},
+ []int{1, 2, 3},
+ true,
+ },
+ {
+ []int{1, 2, 3},
+ []int{1, 2, 3, 4},
+ false,
+ },
+}
+
+var equalFloatTests = []struct {
+ s1, s2 []float64
+ wantEqual bool
+ wantEqualNaN bool
+}{
+ {
+ []float64{1, 2},
+ []float64{1, 2},
+ true,
+ true,
+ },
+ {
+ []float64{1, 2, math.NaN()},
+ []float64{1, 2, math.NaN()},
+ false,
+ true,
+ },
+}
+
+func TestEqual(t *testing.T) {
+ for _, test := range equalIntTests {
+ if got := Equal(test.s1, test.s2); got != test.want {
+ t.Errorf("Equal(%v, %v) = %t, want %t", test.s1, test.s2, got, test.want)
+ }
+ }
+ for _, test := range equalFloatTests {
+ if got := Equal(test.s1, test.s2); got != test.wantEqual {
+ t.Errorf("Equal(%v, %v) = %t, want %t", test.s1, test.s2, got, test.wantEqual)
+ }
+ }
+}
+
+// equal is simply ==.
+func equal[T comparable](v1, v2 T) bool {
+ return v1 == v2
+}
+
+// equalNaN is like == except that all NaNs are equal.
+func equalNaN[T comparable](v1, v2 T) bool {
+ isNaN := func(f T) bool { return f != f }
+ return v1 == v2 || (isNaN(v1) && isNaN(v2))
+}
+
+// offByOne returns true if integers v1 and v2 differ by 1.
+func offByOne(v1, v2 int) bool {
+ return v1 == v2+1 || v1 == v2-1
+}
+
+func TestEqualFunc(t *testing.T) {
+ for _, test := range equalIntTests {
+ if got := EqualFunc(test.s1, test.s2, equal[int]); got != test.want {
+ t.Errorf("EqualFunc(%v, %v, equal[int]) = %t, want %t", test.s1, test.s2, got, test.want)
+ }
+ }
+ for _, test := range equalFloatTests {
+ if got := EqualFunc(test.s1, test.s2, equal[float64]); got != test.wantEqual {
+ t.Errorf("Equal(%v, %v, equal[float64]) = %t, want %t", test.s1, test.s2, got, test.wantEqual)
+ }
+ if got := EqualFunc(test.s1, test.s2, equalNaN[float64]); got != test.wantEqualNaN {
+ t.Errorf("Equal(%v, %v, equalNaN[float64]) = %t, want %t", test.s1, test.s2, got, test.wantEqualNaN)
+ }
+ }
+
+ s1 := []int{1, 2, 3}
+ s2 := []int{2, 3, 4}
+ if EqualFunc(s1, s1, offByOne) {
+ t.Errorf("EqualFunc(%v, %v, offByOne) = true, want false", s1, s1)
+ }
+ if !EqualFunc(s1, s2, offByOne) {
+ t.Errorf("EqualFunc(%v, %v, offByOne) = false, want true", s1, s2)
+ }
+
+ s3 := []string{"a", "b", "c"}
+ s4 := []string{"A", "B", "C"}
+ if !EqualFunc(s3, s4, strings.EqualFold) {
+ t.Errorf("EqualFunc(%v, %v, strings.EqualFold) = false, want true", s3, s4)
+ }
+
+ cmpIntString := func(v1 int, v2 string) bool {
+ return string(rune(v1)-1+'a') == v2
+ }
+ if !EqualFunc(s1, s3, cmpIntString) {
+ t.Errorf("EqualFunc(%v, %v, cmpIntString) = false, want true", s1, s3)
+ }
+}
+
+func BenchmarkEqualFunc_Large(b *testing.B) {
+ type Large [4 * 1024]byte
+
+ xs := make([]Large, 1024)
+ ys := make([]Large, 1024)
+ for i := 0; i < b.N; i++ {
+ _ = EqualFunc(xs, ys, func(x, y Large) bool { return x == y })
+ }
+}
+
+var compareIntTests = []struct {
+ s1, s2 []int
+ want int
+}{
+ {
+ []int{1},
+ []int{1},
+ 0,
+ },
+ {
+ []int{1},
+ []int{},
+ 1,
+ },
+ {
+ []int{},
+ []int{1},
+ -1,
+ },
+ {
+ []int{},
+ []int{},
+ 0,
+ },
+ {
+ []int{1, 2, 3},
+ []int{1, 2, 3},
+ 0,
+ },
+ {
+ []int{1, 2, 3},
+ []int{1, 2, 3, 4},
+ -1,
+ },
+ {
+ []int{1, 2, 3, 4},
+ []int{1, 2, 3},
+ +1,
+ },
+ {
+ []int{1, 2, 3},
+ []int{1, 4, 3},
+ -1,
+ },
+ {
+ []int{1, 4, 3},
+ []int{1, 2, 3},
+ +1,
+ },
+ {
+ []int{1, 4, 3},
+ []int{1, 2, 3, 8, 9},
+ +1,
+ },
+}
+
+var compareFloatTests = []struct {
+ s1, s2 []float64
+ want int
+}{
+ {
+ []float64{},
+ []float64{},
+ 0,
+ },
+ {
+ []float64{1},
+ []float64{1},
+ 0,
+ },
+ {
+ []float64{math.NaN()},
+ []float64{math.NaN()},
+ 0,
+ },
+ {
+ []float64{1, 2, math.NaN()},
+ []float64{1, 2, math.NaN()},
+ 0,
+ },
+ {
+ []float64{1, math.NaN(), 3},
+ []float64{1, math.NaN(), 4},
+ -1,
+ },
+ {
+ []float64{1, math.NaN(), 3},
+ []float64{1, 2, 4},
+ -1,
+ },
+ {
+ []float64{1, math.NaN(), 3},
+ []float64{1, 2, math.NaN()},
+ -1,
+ },
+ {
+ []float64{1, 2, 3},
+ []float64{1, 2, math.NaN()},
+ +1,
+ },
+ {
+ []float64{1, 2, 3},
+ []float64{1, math.NaN(), 3},
+ +1,
+ },
+ {
+ []float64{1, math.NaN(), 3, 4},
+ []float64{1, 2, math.NaN()},
+ -1,
+ },
+}
+
+func TestCompare(t *testing.T) {
+ intWant := func(want bool) string {
+ if want {
+ return "0"
+ }
+ return "!= 0"
+ }
+ for _, test := range equalIntTests {
+ if got := Compare(test.s1, test.s2); (got == 0) != test.want {
+ t.Errorf("Compare(%v, %v) = %d, want %s", test.s1, test.s2, got, intWant(test.want))
+ }
+ }
+ for _, test := range equalFloatTests {
+ if got := Compare(test.s1, test.s2); (got == 0) != test.wantEqualNaN {
+ t.Errorf("Compare(%v, %v) = %d, want %s", test.s1, test.s2, got, intWant(test.wantEqualNaN))
+ }
+ }
+
+ for _, test := range compareIntTests {
+ if got := Compare(test.s1, test.s2); got != test.want {
+ t.Errorf("Compare(%v, %v) = %d, want %d", test.s1, test.s2, got, test.want)
+ }
+ }
+ for _, test := range compareFloatTests {
+ if got := Compare(test.s1, test.s2); got != test.want {
+ t.Errorf("Compare(%v, %v) = %d, want %d", test.s1, test.s2, got, test.want)
+ }
+ }
+}
+
+func equalToCmp[T comparable](eq func(T, T) bool) func(T, T) int {
+ return func(v1, v2 T) int {
+ if eq(v1, v2) {
+ return 0
+ }
+ return 1
+ }
+}
+
+func TestCompareFunc(t *testing.T) {
+ intWant := func(want bool) string {
+ if want {
+ return "0"
+ }
+ return "!= 0"
+ }
+ for _, test := range equalIntTests {
+ if got := CompareFunc(test.s1, test.s2, equalToCmp(equal[int])); (got == 0) != test.want {
+ t.Errorf("CompareFunc(%v, %v, equalToCmp(equal[int])) = %d, want %s", test.s1, test.s2, got, intWant(test.want))
+ }
+ }
+ for _, test := range equalFloatTests {
+ if got := CompareFunc(test.s1, test.s2, equalToCmp(equal[float64])); (got == 0) != test.wantEqual {
+ t.Errorf("CompareFunc(%v, %v, equalToCmp(equal[float64])) = %d, want %s", test.s1, test.s2, got, intWant(test.wantEqual))
+ }
+ }
+
+ for _, test := range compareIntTests {
+ if got := CompareFunc(test.s1, test.s2, cmp.Compare[int]); got != test.want {
+ t.Errorf("CompareFunc(%v, %v, cmp[int]) = %d, want %d", test.s1, test.s2, got, test.want)
+ }
+ }
+ for _, test := range compareFloatTests {
+ if got := CompareFunc(test.s1, test.s2, cmp.Compare[float64]); got != test.want {
+ t.Errorf("CompareFunc(%v, %v, cmp[float64]) = %d, want %d", test.s1, test.s2, got, test.want)
+ }
+ }
+
+ s1 := []int{1, 2, 3}
+ s2 := []int{2, 3, 4}
+ if got := CompareFunc(s1, s2, equalToCmp(offByOne)); got != 0 {
+ t.Errorf("CompareFunc(%v, %v, offByOne) = %d, want 0", s1, s2, got)
+ }
+
+ s3 := []string{"a", "b", "c"}
+ s4 := []string{"A", "B", "C"}
+ if got := CompareFunc(s3, s4, strings.Compare); got != 1 {
+ t.Errorf("CompareFunc(%v, %v, strings.Compare) = %d, want 1", s3, s4, got)
+ }
+
+ compareLower := func(v1, v2 string) int {
+ return strings.Compare(strings.ToLower(v1), strings.ToLower(v2))
+ }
+ if got := CompareFunc(s3, s4, compareLower); got != 0 {
+ t.Errorf("CompareFunc(%v, %v, compareLower) = %d, want 0", s3, s4, got)
+ }
+
+ cmpIntString := func(v1 int, v2 string) int {
+ return strings.Compare(string(rune(v1)-1+'a'), v2)
+ }
+ if got := CompareFunc(s1, s3, cmpIntString); got != 0 {
+ t.Errorf("CompareFunc(%v, %v, cmpIntString) = %d, want 0", s1, s3, got)
+ }
+}
+
+var indexTests = []struct {
+ s []int
+ v int
+ want int
+}{
+ {
+ nil,
+ 0,
+ -1,
+ },
+ {
+ []int{},
+ 0,
+ -1,
+ },
+ {
+ []int{1, 2, 3},
+ 2,
+ 1,
+ },
+ {
+ []int{1, 2, 2, 3},
+ 2,
+ 1,
+ },
+ {
+ []int{1, 2, 3, 2},
+ 2,
+ 1,
+ },
+}
+
+func TestIndex(t *testing.T) {
+ for _, test := range indexTests {
+ if got := Index(test.s, test.v); got != test.want {
+ t.Errorf("Index(%v, %v) = %d, want %d", test.s, test.v, got, test.want)
+ }
+ }
+}
+
+func equalToIndex[T any](f func(T, T) bool, v1 T) func(T) bool {
+ return func(v2 T) bool {
+ return f(v1, v2)
+ }
+}
+
+func BenchmarkIndex_Large(b *testing.B) {
+ type Large [4 * 1024]byte
+
+ ss := make([]Large, 1024)
+ for i := 0; i < b.N; i++ {
+ _ = Index(ss, Large{1})
+ }
+}
+
+func TestIndexFunc(t *testing.T) {
+ for _, test := range indexTests {
+ if got := IndexFunc(test.s, equalToIndex(equal[int], test.v)); got != test.want {
+ t.Errorf("IndexFunc(%v, equalToIndex(equal[int], %v)) = %d, want %d", test.s, test.v, got, test.want)
+ }
+ }
+
+ s1 := []string{"hi", "HI"}
+ if got := IndexFunc(s1, equalToIndex(equal[string], "HI")); got != 1 {
+ t.Errorf("IndexFunc(%v, equalToIndex(equal[string], %q)) = %d, want %d", s1, "HI", got, 1)
+ }
+ if got := IndexFunc(s1, equalToIndex(strings.EqualFold, "HI")); got != 0 {
+ t.Errorf("IndexFunc(%v, equalToIndex(strings.EqualFold, %q)) = %d, want %d", s1, "HI", got, 0)
+ }
+}
+
+func BenchmarkIndexFunc_Large(b *testing.B) {
+ type Large [4 * 1024]byte
+
+ ss := make([]Large, 1024)
+ for i := 0; i < b.N; i++ {
+ _ = IndexFunc(ss, func(e Large) bool {
+ return e == Large{1}
+ })
+ }
+}
+
+func TestContains(t *testing.T) {
+ for _, test := range indexTests {
+ if got := Contains(test.s, test.v); got != (test.want != -1) {
+ t.Errorf("Contains(%v, %v) = %t, want %t", test.s, test.v, got, test.want != -1)
+ }
+ }
+}
+
+func TestContainsFunc(t *testing.T) {
+ for _, test := range indexTests {
+ if got := ContainsFunc(test.s, equalToIndex(equal[int], test.v)); got != (test.want != -1) {
+ t.Errorf("ContainsFunc(%v, equalToIndex(equal[int], %v)) = %t, want %t", test.s, test.v, got, test.want != -1)
+ }
+ }
+
+ s1 := []string{"hi", "HI"}
+ if got := ContainsFunc(s1, equalToIndex(equal[string], "HI")); got != true {
+ t.Errorf("ContainsFunc(%v, equalToContains(equal[string], %q)) = %t, want %t", s1, "HI", got, true)
+ }
+ if got := ContainsFunc(s1, equalToIndex(equal[string], "hI")); got != false {
+ t.Errorf("ContainsFunc(%v, equalToContains(strings.EqualFold, %q)) = %t, want %t", s1, "hI", got, false)
+ }
+ if got := ContainsFunc(s1, equalToIndex(strings.EqualFold, "hI")); got != true {
+ t.Errorf("ContainsFunc(%v, equalToContains(strings.EqualFold, %q)) = %t, want %t", s1, "hI", got, true)
+ }
+}
+
+var insertTests = []struct {
+ s []int
+ i int
+ add []int
+ want []int
+}{
+ {
+ []int{1, 2, 3},
+ 0,
+ []int{4},
+ []int{4, 1, 2, 3},
+ },
+ {
+ []int{1, 2, 3},
+ 1,
+ []int{4},
+ []int{1, 4, 2, 3},
+ },
+ {
+ []int{1, 2, 3},
+ 3,
+ []int{4},
+ []int{1, 2, 3, 4},
+ },
+ {
+ []int{1, 2, 3},
+ 2,
+ []int{4, 5},
+ []int{1, 2, 4, 5, 3},
+ },
+}
+
+func TestInsert(t *testing.T) {
+ s := []int{1, 2, 3}
+ if got := Insert(s, 0); !Equal(got, s) {
+ t.Errorf("Insert(%v, 0) = %v, want %v", s, got, s)
+ }
+ for _, test := range insertTests {
+ copy := Clone(test.s)
+ if got := Insert(copy, test.i, test.add...); !Equal(got, test.want) {
+ t.Errorf("Insert(%v, %d, %v...) = %v, want %v", test.s, test.i, test.add, got, test.want)
+ }
+ }
+
+ if !testenv.OptimizationOff() && !race.Enabled {
+ // Allocations should be amortized.
+ const count = 50
+ n := testing.AllocsPerRun(10, func() {
+ s := []int{1, 2, 3}
+ for i := 0; i < count; i++ {
+ s = Insert(s, 0, 1)
+ }
+ })
+ if n > count/2 {
+ t.Errorf("too many allocations inserting %d elements: got %v, want less than %d", count, n, count/2)
+ }
+ }
+}
+
+func TestInsertOverlap(t *testing.T) {
+ const N = 10
+ a := make([]int, N)
+ want := make([]int, 2*N)
+ for n := 0; n <= N; n++ { // length
+ for i := 0; i <= n; i++ { // insertion point
+ for x := 0; x <= N; x++ { // start of inserted data
+ for y := x; y <= N; y++ { // end of inserted data
+ for k := 0; k < N; k++ {
+ a[k] = k
+ }
+ want = want[:0]
+ want = append(want, a[:i]...)
+ want = append(want, a[x:y]...)
+ want = append(want, a[i:n]...)
+ got := Insert(a[:n], i, a[x:y]...)
+ if !Equal(got, want) {
+ t.Errorf("Insert with overlap failed n=%d i=%d x=%d y=%d, got %v want %v", n, i, x, y, got, want)
+ }
+ }
+ }
+ }
+ }
+}
+
+var deleteTests = []struct {
+ s []int
+ i, j int
+ want []int
+}{
+ {
+ []int{1, 2, 3},
+ 0,
+ 0,
+ []int{1, 2, 3},
+ },
+ {
+ []int{1, 2, 3},
+ 0,
+ 1,
+ []int{2, 3},
+ },
+ {
+ []int{1, 2, 3},
+ 3,
+ 3,
+ []int{1, 2, 3},
+ },
+ {
+ []int{1, 2, 3},
+ 0,
+ 2,
+ []int{3},
+ },
+ {
+ []int{1, 2, 3},
+ 0,
+ 3,
+ []int{},
+ },
+}
+
+func TestDelete(t *testing.T) {
+ for _, test := range deleteTests {
+ copy := Clone(test.s)
+ if got := Delete(copy, test.i, test.j); !Equal(got, test.want) {
+ t.Errorf("Delete(%v, %d, %d) = %v, want %v", test.s, test.i, test.j, got, test.want)
+ }
+ }
+}
+
+var deleteFuncTests = []struct {
+ s []int
+ fn func(int) bool
+ want []int
+}{
+ {
+ nil,
+ func(int) bool { return true },
+ nil,
+ },
+ {
+ []int{1, 2, 3},
+ func(int) bool { return true },
+ nil,
+ },
+ {
+ []int{1, 2, 3},
+ func(int) bool { return false },
+ []int{1, 2, 3},
+ },
+ {
+ []int{1, 2, 3},
+ func(i int) bool { return i > 2 },
+ []int{1, 2},
+ },
+ {
+ []int{1, 2, 3},
+ func(i int) bool { return i < 2 },
+ []int{2, 3},
+ },
+ {
+ []int{10, 2, 30},
+ func(i int) bool { return i >= 10 },
+ []int{2},
+ },
+}
+
+func TestDeleteFunc(t *testing.T) {
+ for i, test := range deleteFuncTests {
+ copy := Clone(test.s)
+ if got := DeleteFunc(copy, test.fn); !Equal(got, test.want) {
+ t.Errorf("DeleteFunc case %d: got %v, want %v", i, got, test.want)
+ }
+ }
+}
+
+func panics(f func()) (b bool) {
+ defer func() {
+ if x := recover(); x != nil {
+ b = true
+ }
+ }()
+ f()
+ return false
+}
+
+func TestDeletePanics(t *testing.T) {
+ for _, test := range []struct {
+ name string
+ s []int
+ i, j int
+ }{
+ {"with negative first index", []int{42}, -2, 1},
+ {"with negative second index", []int{42}, 1, -1},
+ {"with out-of-bounds first index", []int{42}, 2, 3},
+ {"with out-of-bounds second index", []int{42}, 0, 2},
+ {"with invalid i>j", []int{42}, 1, 0},
+ } {
+ if !panics(func() { _ = Delete(test.s, test.i, test.j) }) {
+ t.Errorf("Delete %s: got no panic, want panic", test.name)
+ }
+ }
+}
+
+func TestClone(t *testing.T) {
+ s1 := []int{1, 2, 3}
+ s2 := Clone(s1)
+ if !Equal(s1, s2) {
+ t.Errorf("Clone(%v) = %v, want %v", s1, s2, s1)
+ }
+ s1[0] = 4
+ want := []int{1, 2, 3}
+ if !Equal(s2, want) {
+ t.Errorf("Clone(%v) changed unexpectedly to %v", want, s2)
+ }
+ if got := Clone([]int(nil)); got != nil {
+ t.Errorf("Clone(nil) = %#v, want nil", got)
+ }
+ if got := Clone(s1[:0]); got == nil || len(got) != 0 {
+ t.Errorf("Clone(%v) = %#v, want %#v", s1[:0], got, s1[:0])
+ }
+}
+
+var compactTests = []struct {
+ name string
+ s []int
+ want []int
+}{
+ {
+ "nil",
+ nil,
+ nil,
+ },
+ {
+ "one",
+ []int{1},
+ []int{1},
+ },
+ {
+ "sorted",
+ []int{1, 2, 3},
+ []int{1, 2, 3},
+ },
+ {
+ "1 item",
+ []int{1, 1, 2},
+ []int{1, 2},
+ },
+ {
+ "unsorted",
+ []int{1, 2, 1},
+ []int{1, 2, 1},
+ },
+ {
+ "many",
+ []int{1, 2, 2, 3, 3, 4},
+ []int{1, 2, 3, 4},
+ },
+}
+
+func TestCompact(t *testing.T) {
+ for _, test := range compactTests {
+ copy := Clone(test.s)
+ if got := Compact(copy); !Equal(got, test.want) {
+ t.Errorf("Compact(%v) = %v, want %v", test.s, got, test.want)
+ }
+ }
+}
+
+func BenchmarkCompact(b *testing.B) {
+ for _, c := range compactTests {
+ b.Run(c.name, func(b *testing.B) {
+ ss := make([]int, 0, 64)
+ for k := 0; k < b.N; k++ {
+ ss = ss[:0]
+ ss = append(ss, c.s...)
+ _ = Compact(ss)
+ }
+ })
+ }
+}
+
+func BenchmarkCompact_Large(b *testing.B) {
+ type Large [4 * 1024]byte
+
+ ss := make([]Large, 1024)
+ for i := 0; i < b.N; i++ {
+ _ = Compact(ss)
+ }
+}
+
+func TestCompactFunc(t *testing.T) {
+ for _, test := range compactTests {
+ copy := Clone(test.s)
+ if got := CompactFunc(copy, equal[int]); !Equal(got, test.want) {
+ t.Errorf("CompactFunc(%v, equal[int]) = %v, want %v", test.s, got, test.want)
+ }
+ }
+
+ s1 := []string{"a", "a", "A", "B", "b"}
+ copy := Clone(s1)
+ want := []string{"a", "B"}
+ if got := CompactFunc(copy, strings.EqualFold); !Equal(got, want) {
+ t.Errorf("CompactFunc(%v, strings.EqualFold) = %v, want %v", s1, got, want)
+ }
+}
+
+func BenchmarkCompactFunc_Large(b *testing.B) {
+ type Large [4 * 1024]byte
+
+ ss := make([]Large, 1024)
+ for i := 0; i < b.N; i++ {
+ _ = CompactFunc(ss, func(a, b Large) bool { return a == b })
+ }
+}
+
+func TestGrow(t *testing.T) {
+ s1 := []int{1, 2, 3}
+
+ copy := Clone(s1)
+ s2 := Grow(copy, 1000)
+ if !Equal(s1, s2) {
+ t.Errorf("Grow(%v) = %v, want %v", s1, s2, s1)
+ }
+ if cap(s2) < 1000+len(s1) {
+ t.Errorf("after Grow(%v) cap = %d, want >= %d", s1, cap(s2), 1000+len(s1))
+ }
+
+ // Test mutation of elements between length and capacity.
+ copy = Clone(s1)
+ s3 := Grow(copy[:1], 2)[:3]
+ if !Equal(s1, s3) {
+ t.Errorf("Grow should not mutate elements between length and capacity")
+ }
+ s3 = Grow(copy[:1], 1000)[:3]
+ if !Equal(s1, s3) {
+ t.Errorf("Grow should not mutate elements between length and capacity")
+ }
+
+ // Test number of allocations.
+ if n := testing.AllocsPerRun(100, func() { _ = Grow(s2, cap(s2)-len(s2)) }); n != 0 {
+ t.Errorf("Grow should not allocate when given sufficient capacity; allocated %v times", n)
+ }
+ if n := testing.AllocsPerRun(100, func() { _ = Grow(s2, cap(s2)-len(s2)+1) }); n != 1 {
+ errorf := t.Errorf
+ if race.Enabled || testenv.OptimizationOff() {
+ errorf = t.Logf // this allocates multiple times in race detector mode
+ }
+ errorf("Grow should allocate once when given insufficient capacity; allocated %v times", n)
+ }
+
+ // Test for negative growth sizes.
+ var gotPanic bool
+ func() {
+ defer func() { gotPanic = recover() != nil }()
+ _ = Grow(s1, -1)
+ }()
+ if !gotPanic {
+ t.Errorf("Grow(-1) did not panic; expected a panic")
+ }
+}
+
+func TestClip(t *testing.T) {
+ s1 := []int{1, 2, 3, 4, 5, 6}[:3]
+ orig := Clone(s1)
+ if len(s1) != 3 {
+ t.Errorf("len(%v) = %d, want 3", s1, len(s1))
+ }
+ if cap(s1) < 6 {
+ t.Errorf("cap(%v[:3]) = %d, want >= 6", orig, cap(s1))
+ }
+ s2 := Clip(s1)
+ if !Equal(s1, s2) {
+ t.Errorf("Clip(%v) = %v, want %v", s1, s2, s1)
+ }
+ if cap(s2) != 3 {
+ t.Errorf("cap(Clip(%v)) = %d, want 3", orig, cap(s2))
+ }
+}
+
+func TestReverse(t *testing.T) {
+ even := []int{3, 1, 4, 1, 5, 9} // len = 6
+ Reverse(even)
+ if want := []int{9, 5, 1, 4, 1, 3}; !Equal(even, want) {
+ t.Errorf("Reverse(even) = %v, want %v", even, want)
+ }
+
+ odd := []int{3, 1, 4, 1, 5, 9, 2} // len = 7
+ Reverse(odd)
+ if want := []int{2, 9, 5, 1, 4, 1, 3}; !Equal(odd, want) {
+ t.Errorf("Reverse(odd) = %v, want %v", odd, want)
+ }
+
+ words := strings.Fields("one two three")
+ Reverse(words)
+ if want := strings.Fields("three two one"); !Equal(words, want) {
+ t.Errorf("Reverse(words) = %v, want %v", words, want)
+ }
+
+ singleton := []string{"one"}
+ Reverse(singleton)
+ if want := []string{"one"}; !Equal(singleton, want) {
+ t.Errorf("Reverse(singeleton) = %v, want %v", singleton, want)
+ }
+
+ Reverse[[]string](nil)
+}
+
+// naiveReplace is a baseline implementation to the Replace function.
+func naiveReplace[S ~[]E, E any](s S, i, j int, v ...E) S {
+ s = Delete(s, i, j)
+ s = Insert(s, i, v...)
+ return s
+}
+
+func TestReplace(t *testing.T) {
+ for _, test := range []struct {
+ s, v []int
+ i, j int
+ }{
+ {}, // all zero value
+ {
+ s: []int{1, 2, 3, 4},
+ v: []int{5},
+ i: 1,
+ j: 2,
+ },
+ {
+ s: []int{1, 2, 3, 4},
+ v: []int{5, 6, 7, 8},
+ i: 1,
+ j: 2,
+ },
+ {
+ s: func() []int {
+ s := make([]int, 3, 20)
+ s[0] = 0
+ s[1] = 1
+ s[2] = 2
+ return s
+ }(),
+ v: []int{3, 4, 5, 6, 7},
+ i: 0,
+ j: 1,
+ },
+ } {
+ ss, vv := Clone(test.s), Clone(test.v)
+ want := naiveReplace(ss, test.i, test.j, vv...)
+ got := Replace(test.s, test.i, test.j, test.v...)
+ if !Equal(got, want) {
+ t.Errorf("Replace(%v, %v, %v, %v) = %v, want %v", test.s, test.i, test.j, test.v, got, want)
+ }
+ }
+}
+
+func TestReplacePanics(t *testing.T) {
+ for _, test := range []struct {
+ name string
+ s, v []int
+ i, j int
+ }{
+ {"indexes out of order", []int{1, 2}, []int{3}, 2, 1},
+ {"large index", []int{1, 2}, []int{3}, 1, 10},
+ {"negative index", []int{1, 2}, []int{3}, -1, 2},
+ } {
+ ss, vv := Clone(test.s), Clone(test.v)
+ if !panics(func() { _ = Replace(ss, test.i, test.j, vv...) }) {
+ t.Errorf("Replace %s: should have panicked", test.name)
+ }
+ }
+}
+
+func TestReplaceOverlap(t *testing.T) {
+ const N = 10
+ a := make([]int, N)
+ want := make([]int, 2*N)
+ for n := 0; n <= N; n++ { // length
+ for i := 0; i <= n; i++ { // insertion point 1
+ for j := i; j <= n; j++ { // insertion point 2
+ for x := 0; x <= N; x++ { // start of inserted data
+ for y := x; y <= N; y++ { // end of inserted data
+ for k := 0; k < N; k++ {
+ a[k] = k
+ }
+ want = want[:0]
+ want = append(want, a[:i]...)
+ want = append(want, a[x:y]...)
+ want = append(want, a[j:n]...)
+ got := Replace(a[:n], i, j, a[x:y]...)
+ if !Equal(got, want) {
+ t.Errorf("Insert with overlap failed n=%d i=%d j=%d x=%d y=%d, got %v want %v", n, i, j, x, y, got, want)
+ }
+ }
+ }
+ }
+ }
+ }
+}
+
+func BenchmarkReplace(b *testing.B) {
+ cases := []struct {
+ name string
+ s, v func() []int
+ i, j int
+ }{
+ {
+ name: "fast",
+ s: func() []int {
+ return make([]int, 100)
+ },
+ v: func() []int {
+ return make([]int, 20)
+ },
+ i: 10,
+ j: 40,
+ },
+ {
+ name: "slow",
+ s: func() []int {
+ return make([]int, 100)
+ },
+ v: func() []int {
+ return make([]int, 20)
+ },
+ i: 0,
+ j: 2,
+ },
+ }
+
+ for _, c := range cases {
+ b.Run("naive-"+c.name, func(b *testing.B) {
+ for k := 0; k < b.N; k++ {
+ s := c.s()
+ v := c.v()
+ _ = naiveReplace(s, c.i, c.j, v...)
+ }
+ })
+ b.Run("optimized-"+c.name, func(b *testing.B) {
+ for k := 0; k < b.N; k++ {
+ s := c.s()
+ v := c.v()
+ _ = Replace(s, c.i, c.j, v...)
+ }
+ })
+ }
+
+}
+
+func TestRotate(t *testing.T) {
+ const N = 10
+ s := make([]int, 0, N)
+ for n := 0; n < N; n++ {
+ for r := 0; r < n; r++ {
+ s = s[:0]
+ for i := 0; i < n; i++ {
+ s = append(s, i)
+ }
+ rotateLeft(s, r)
+ for i := 0; i < n; i++ {
+ if s[i] != (i+r)%n {
+ t.Errorf("expected n=%d r=%d i:%d want:%d got:%d", n, r, i, (i+r)%n, s[i])
+ }
+ }
+ }
+ }
+}
+
+func TestInsertGrowthRate(t *testing.T) {
+ b := make([]byte, 1)
+ maxCap := cap(b)
+ nGrow := 0
+ const N = 1e6
+ for i := 0; i < N; i++ {
+ b = Insert(b, len(b)-1, 0)
+ if cap(b) > maxCap {
+ maxCap = cap(b)
+ nGrow++
+ }
+ }
+ want := int(math.Log(N) / math.Log(1.25)) // 1.25 == growth rate for large slices
+ if nGrow > want {
+ t.Errorf("too many grows. got:%d want:%d", nGrow, want)
+ }
+}
+
+func TestReplaceGrowthRate(t *testing.T) {
+ b := make([]byte, 2)
+ maxCap := cap(b)
+ nGrow := 0
+ const N = 1e6
+ for i := 0; i < N; i++ {
+ b = Replace(b, len(b)-2, len(b)-1, 0, 0)
+ if cap(b) > maxCap {
+ maxCap = cap(b)
+ nGrow++
+ }
+ }
+ want := int(math.Log(N) / math.Log(1.25)) // 1.25 == growth rate for large slices
+ if nGrow > want {
+ t.Errorf("too many grows. got:%d want:%d", nGrow, want)
+ }
+}
+
+func apply[T any](v T, f func(T)) {
+ f(v)
+}
+
+// Test type inference with a named slice type.
+func TestInference(t *testing.T) {
+ s1 := []int{1, 2, 3}
+ apply(s1, Reverse)
+ if want := []int{3, 2, 1}; !Equal(s1, want) {
+ t.Errorf("Reverse(%v) = %v, want %v", []int{1, 2, 3}, s1, want)
+ }
+
+ type S []int
+ s2 := S{4, 5, 6}
+ apply(s2, Reverse)
+ if want := (S{6, 5, 4}); !Equal(s2, want) {
+ t.Errorf("Reverse(%v) = %v, want %v", S{4, 5, 6}, s2, want)
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-08 17:02:07 +0000