summaryrefslogtreecommitdiff
path: root/go/diamond/diamond_test.go
blob: 637287890b237d7558aba0338a7089d2433e5e57 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
package diamond

import (
	"math/rand"
	"reflect"
	"strings"
	"testing"
	"testing/quick"
	"time"
)

var config = &quick.Config{Rand: rand.New(rand.NewSource(time.Now().UnixNano()))}

type correctChar byte

func (c correctChar) Generate(rand *rand.Rand, _ int) reflect.Value {
	return reflect.ValueOf(correctChar('A' + rand.Intn('Z'-'A'+1)))
}

func checkCorrect(requirement func(byte, []string) bool, keepSeparator bool, t *testing.T) {
	assertion := func(char correctChar) bool {
		d, err := Gen(byte(char))
		if err != nil {
			return false
		}
		separator := strings.Split
		if keepSeparator {
			separator = strings.SplitAfter
		}
		rows := separator(d, "\n")
		if len(rows) < 2 {
			return false
		}
		return requirement(byte(char), rows[:len(rows)-1])
	}
	if err := quick.Check(assertion, config); err != nil {
		t.Error(err)
	}
}

func TestFirstRowContainsOneA(t *testing.T) {
	requirement := func(char byte, rows []string) bool {
		return len(rows) > 0 && strings.Count(rows[0], "A") == 1
	}
	checkCorrect(requirement, false, t)
}

func TestLastRowContainsOneA(t *testing.T) {
	requirement := func(char byte, rows []string) bool {
		return len(rows) > 0 && strings.Count(rows[len(rows)-1], "A") == 1
	}
	checkCorrect(requirement, false, t)
}

func TestAllRowsIdenticalLettersExceptFirstAndLast(t *testing.T) {
	requirement := func(char byte, rows []string) bool {
		for i, row := range rows {
			r := strings.TrimSpace(row)
			if r[0] != r[len(r)-1] {
				return false
			}
			if len(r) < 2 && i != 0 && i != len(rows)-1 {
				return false
			}
		}
		return true
	}
	checkCorrect(requirement, false, t)
}

func TestAllRowsHaveSameTrailingSpaces(t *testing.T) {
	requirement := func(char byte, rows []string) bool {
		for _, row := range rows {
			if len(row) == 0 {
				return false
			}
			for i, j := 0, len(row)-1; i < j && row[i] == ' '; i, j = i+1, j-1 {
				if row[j] != ' ' {
					return false
				}
			}
		}
		return true
	}
	checkCorrect(requirement, false, t)
}

func TestDiamondIsHorizontallySymmetric(t *testing.T) {
	requirement := func(char byte, rows []string) bool {
		for _, row := range rows {
			l := len(row)
			for i := l/2 - 1; i >= 0; i-- {
				if row[i] != row[l-1-i] {
					return false
				}
			}
		}
		return true
	}
	checkCorrect(requirement, false, t)
}

func TestDiamondIsVerticallySymmetric(t *testing.T) {
	requirement := func(char byte, rows []string) bool {
		for i, j := 0, len(rows)-1; i < j; i, j = i+1, j-1 {
			if rows[i] != rows[j] {
				return false
			}
		}
		return true
	}
	checkCorrect(requirement, true, t)
}

func TestDiamondIsSquare(t *testing.T) {
	requirement := func(char byte, rows []string) bool {
		if int(char-'A')*2+1 != len(rows) {
			return false
		}
		for _, row := range rows {
			if len(row) != len(rows) {
				return false
			}
		}
		return true
	}
	checkCorrect(requirement, false, t)
}

func TestDiamondHasItsShape(t *testing.T) {
	requirement := func(char byte, rows []string) bool {
		var n int
		for i, row := range rows {
			s := len(strings.TrimSpace(row))
			if i > len(rows)/2 && n <= s {
				return false
			} else if i <= len(rows)/2 && n >= s {
				return false
			}
			n = s
		}
		return true
	}
	checkCorrect(requirement, false, t)
}

func TestTopHalfHasAscendingLetters(t *testing.T) {
	requirement := func(char byte, rows []string) bool {
		var start byte = 'A' - 1
		for i := 0; i <= len(rows)/2; i++ {
			s := strings.TrimLeft(rows[i], " ")
			if s == "" || s[0] <= start {
				return false
			}
			start = s[0]
		}
		return true
	}
	checkCorrect(requirement, false, t)
}

func TestBottomHalfHasDescendingLetters(t *testing.T) {
	requirement := func(char byte, rows []string) bool {
		var start byte = 'A' - 1
		for i := len(rows) - 1; i > len(rows)/2; i-- {
			s := strings.TrimLeft(rows[i], " ")
			if s == "" || s[0] <= start {
				return false
			}
			start = s[0]
		}
		return true
	}
	checkCorrect(requirement, false, t)
}

func TestDiamondFourCornersAreTriangle(t *testing.T) {
	requirement := func(char byte, rows []string) bool {
		notSpace := func(r rune) bool { return r <= 'Z' && r >= 'A' }
		var n int
		for i, row := range rows {
			s := strings.IndexFunc(row, notSpace)
			e := len(row) - strings.LastIndexFunc(row, notSpace) - 1
			if s != e {
				return false
			} else if i == 0 {
				n = s
			} else {
				if i > len(rows)/2 && n >= s {
					return false
				} else if i <= len(rows)/2 && n <= s {
					return false
				}
				n = s
			}
		}
		return true
	}
	checkCorrect(requirement, false, t)
}

type wrongChar byte

func (c wrongChar) Generate(rand *rand.Rand, _ int) reflect.Value {
	b := rand.Intn(256)
	for ; b >= 'A' && b <= 'Z'; b = rand.Intn(256) {
	}
	return reflect.ValueOf(wrongChar(b))
}

func TestCharOutOfRangeShouldGiveError(t *testing.T) {
	assertion := func(char wrongChar) bool {
		_, err := Gen(byte(char))
		return err != nil
	}
	if err := quick.Check(assertion, config); err != nil {
		t.Error(err)
	}
}

const targetTestVersion = 1

func TestTestVersion(t *testing.T) {
	if testVersion != targetTestVersion {
		t.Errorf("Found testVersion = %v, want %v.", testVersion, targetTestVersion)
	}
}