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-rw-r--r--src/slices/slices_test.go604
1 files changed, 604 insertions, 0 deletions
diff --git a/src/slices/slices_test.go b/src/slices/slices_test.go
new file mode 100644
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+++ b/src/slices/slices_test.go
@@ -0,0 +1,604 @@
+// 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 (
+ "internal/race"
+ "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)
+ }
+}
+
+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 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 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)
+ }
+ }
+}
+
+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)
+ }
+ }
+}
+
+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 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 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 {
+ 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))
+ }
+}
+
+// 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 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...)
+ }
+ })
+ }
+
+}
generated by cgit v1.3 (git 2.53.0) at 2026-04-15 04:13:15 +0000