maps_test.go

Documentation: golang.org/x/exp/maps

     1  // Copyright 2021 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package maps
     6  
     7  import (
     8  	"math"
     9  	"sort"
    10  	"strconv"
    11  	"testing"
    12  
    13  	"golang.org/x/exp/slices"
    14  )
    15  
    16  var m1 = map[int]int{1: 2, 2: 4, 4: 8, 8: 16}
    17  var m2 = map[int]string{1: "2", 2: "4", 4: "8", 8: "16"}
    18  
    19  func TestKeys(t *testing.T) {
    20  	want := []int{1, 2, 4, 8}
    21  
    22  	got1 := Keys(m1)
    23  	sort.Ints(got1)
    24  	if !slices.Equal(got1, want) {
    25  		t.Errorf("Keys(%v) = %v, want %v", m1, got1, want)
    26  	}
    27  
    28  	got2 := Keys(m2)
    29  	sort.Ints(got2)
    30  	if !slices.Equal(got2, want) {
    31  		t.Errorf("Keys(%v) = %v, want %v", m2, got2, want)
    32  	}
    33  }
    34  
    35  func TestValues(t *testing.T) {
    36  	got1 := Values(m1)
    37  	want1 := []int{2, 4, 8, 16}
    38  	sort.Ints(got1)
    39  	if !slices.Equal(got1, want1) {
    40  		t.Errorf("Values(%v) = %v, want %v", m1, got1, want1)
    41  	}
    42  
    43  	got2 := Values(m2)
    44  	want2 := []string{"16", "2", "4", "8"}
    45  	sort.Strings(got2)
    46  	if !slices.Equal(got2, want2) {
    47  		t.Errorf("Values(%v) = %v, want %v", m2, got2, want2)
    48  	}
    49  }
    50  
    51  func TestEqual(t *testing.T) {
    52  	if !Equal(m1, m1) {
    53  		t.Errorf("Equal(%v, %v) = false, want true", m1, m1)
    54  	}
    55  	if Equal(m1, (map[int]int)(nil)) {
    56  		t.Errorf("Equal(%v, nil) = true, want false", m1)
    57  	}
    58  	if Equal((map[int]int)(nil), m1) {
    59  		t.Errorf("Equal(nil, %v) = true, want false", m1)
    60  	}
    61  	if !Equal[map[int]int, map[int]int](nil, nil) {
    62  		t.Error("Equal(nil, nil) = false, want true")
    63  	}
    64  	if ms := map[int]int{1: 2}; Equal(m1, ms) {
    65  		t.Errorf("Equal(%v, %v) = true, want false", m1, ms)
    66  	}
    67  
    68  	// Comparing NaN for equality is expected to fail.
    69  	mf := map[int]float64{1: 0, 2: math.NaN()}
    70  	if Equal(mf, mf) {
    71  		t.Errorf("Equal(%v, %v) = true, want false", mf, mf)
    72  	}
    73  }
    74  
    75  // equal is simply ==.
    76  func equal[T comparable](v1, v2 T) bool {
    77  	return v1 == v2
    78  }
    79  
    80  // equalNaN is like == except that all NaNs are equal.
    81  func equalNaN[T comparable](v1, v2 T) bool {
    82  	isNaN := func(f T) bool { return f != f }
    83  	return v1 == v2 || (isNaN(v1) && isNaN(v2))
    84  }
    85  
    86  // equalIntStr compares ints and strings.
    87  func equalIntStr(v1 int, v2 string) bool {
    88  	return strconv.Itoa(v1) == v2
    89  }
    90  
    91  func TestEqualFunc(t *testing.T) {
    92  	if !EqualFunc(m1, m1, equal[int]) {
    93  		t.Errorf("EqualFunc(%v, %v, equal) = false, want true", m1, m1)
    94  	}
    95  	if EqualFunc(m1, (map[int]int)(nil), equal[int]) {
    96  		t.Errorf("EqualFunc(%v, nil, equal) = true, want false", m1)
    97  	}
    98  	if EqualFunc((map[int]int)(nil), m1, equal[int]) {
    99  		t.Errorf("EqualFunc(nil, %v, equal) = true, want false", m1)
   100  	}
   101  	if !EqualFunc[map[int]int, map[int]int](nil, nil, equal[int]) {
   102  		t.Error("EqualFunc(nil, nil, equal) = false, want true")
   103  	}
   104  	if ms := map[int]int{1: 2}; EqualFunc(m1, ms, equal[int]) {
   105  		t.Errorf("EqualFunc(%v, %v, equal) = true, want false", m1, ms)
   106  	}
   107  
   108  	// Comparing NaN for equality is expected to fail.
   109  	mf := map[int]float64{1: 0, 2: math.NaN()}
   110  	if EqualFunc(mf, mf, equal[float64]) {
   111  		t.Errorf("EqualFunc(%v, %v, equal) = true, want false", mf, mf)
   112  	}
   113  	// But it should succeed using equalNaN.
   114  	if !EqualFunc(mf, mf, equalNaN[float64]) {
   115  		t.Errorf("EqualFunc(%v, %v, equalNaN) = false, want true", mf, mf)
   116  	}
   117  
   118  	if !EqualFunc(m1, m2, equalIntStr) {
   119  		t.Errorf("EqualFunc(%v, %v, equalIntStr) = false, want true", m1, m2)
   120  	}
   121  }
   122  
   123  func TestClear(t *testing.T) {
   124  	ml := map[int]int{1: 1, 2: 2, 3: 3}
   125  	Clear(ml)
   126  	if got := len(ml); got != 0 {
   127  		t.Errorf("len(%v) = %d after Clear, want 0", ml, got)
   128  	}
   129  	if !Equal(ml, (map[int]int)(nil)) {
   130  		t.Errorf("Equal(%v, nil) = false, want true", ml)
   131  	}
   132  }
   133  
   134  func TestClone(t *testing.T) {
   135  	mc := Clone(m1)
   136  	if !Equal(mc, m1) {
   137  		t.Errorf("Clone(%v) = %v, want %v", m1, mc, m1)
   138  	}
   139  	mc[16] = 32
   140  	if Equal(mc, m1) {
   141  		t.Errorf("Equal(%v, %v) = true, want false", mc, m1)
   142  	}
   143  }
   144  
   145  func TestCloneNil(t *testing.T) {
   146  	var m1 map[string]int
   147  	mc := Clone(m1)
   148  	if mc != nil {
   149  		t.Errorf("Clone(%v) = %v, want %v", m1, mc, m1)
   150  	}
   151  }
   152  
   153  func TestCopy(t *testing.T) {
   154  	mc := Clone(m1)
   155  	Copy(mc, mc)
   156  	if !Equal(mc, m1) {
   157  		t.Errorf("Copy(%v, %v) = %v, want %v", m1, m1, mc, m1)
   158  	}
   159  	Copy(mc, map[int]int{16: 32})
   160  	want := map[int]int{1: 2, 2: 4, 4: 8, 8: 16, 16: 32}
   161  	if !Equal(mc, want) {
   162  		t.Errorf("Copy result = %v, want %v", mc, want)
   163  	}
   164  
   165  	type M1 map[int]bool
   166  	type M2 map[int]bool
   167  	Copy(make(M1), make(M2))
   168  }
   169  
   170  func TestDeleteFunc(t *testing.T) {
   171  	mc := Clone(m1)
   172  	DeleteFunc(mc, func(int, int) bool { return false })
   173  	if !Equal(mc, m1) {
   174  		t.Errorf("DeleteFunc(%v, true) = %v, want %v", m1, mc, m1)
   175  	}
   176  	DeleteFunc(mc, func(k, v int) bool { return k > 3 })
   177  	want := map[int]int{1: 2, 2: 4}
   178  	if !Equal(mc, want) {
   179  		t.Errorf("DeleteFunc result = %v, want %v", mc, want)
   180  	}
   181  }
   182
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