-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathtern_test.go
More file actions
342 lines (302 loc) · 8.18 KB
/
tern_test.go
File metadata and controls
342 lines (302 loc) · 8.18 KB
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
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
package tern
import (
"errors"
"fmt"
"strings"
"testing"
)
// =============== T & TF ===============
func TestT(t *testing.T) {
if got := T(true, "A", "B"); got != "A" {
t.Fatalf("T(true) = %q, want %q", got, "A")
}
if got := T(false, "A", "B"); got != "B" {
t.Fatalf("T(false) = %q, want %q", got, "B")
}
// zero-value types
if got := T(true, 0, 10); got != 0 {
t.Fatalf("T(true,0,10) = %v, want 0", got)
}
}
func TestTF_Lazy(t *testing.T) {
calledThen := 0
calledElse := 0
thenFn := func() string { calledThen++; return "then" }
elseFn := func() string { calledElse++; return "else" }
got := TF(true, thenFn, elseFn)
if got != "then" || calledThen != 1 || calledElse != 0 {
t.Fatalf("TF(true) got=%q then=%d else=%d", got, calledThen, calledElse)
}
calledThen, calledElse = 0, 0
got = TF(false, thenFn, elseFn)
if got != "else" || calledThen != 0 || calledElse != 1 {
t.Fatalf("TF(false) got=%q then=%d else=%d", got, calledThen, calledElse)
}
}
// =============== When / ElseIf / Else ===============
func TestChain_EagerAndLazy(t *testing.T) {
// eager branches
grade := When[string](95 > 90, "A").
ElseIf(85 > 90, "B").
Else("C")
if grade != "A" {
t.Fatalf("chain eager got=%q want A", grade)
}
// lazy branches
step := 0
grade2 := WhenFn[string](false, func() string { step = 999; return "A" }).
ElseIfFn(true, func() string { step = 1; return "B" }).
ElseFn(func() string { step = 2; return "C" })
if grade2 != "B" || step != 1 {
t.Fatalf("chain lazy got=%q step=%d want B/1", grade2, step)
}
// ensure Else/ElseFn returns only once
out := When[int](false, 1).Else(42)
if out != 42 {
t.Fatalf("Else fallback got=%d want 42", out)
}
out = When[int](true, 7).Else(42)
if out != 7 {
t.Fatalf("Else short-circuit got=%d want 7", out)
}
out = When[int](true, 7).ElseFn(func() int { return 99 })
if out != 7 {
t.Fatalf("ElseFn short-circuit got=%d want 7", out)
}
}
// =============== Nullish / Coalesce ===============
func TestFirstNonZero(t *testing.T) {
{
s, ok := FirstNonZero("", " ", "x")
if !ok || s != "" && strings.TrimSpace(s) == "" { // first non-zero for string is != ""
// Be careful: "" is zero-value, " " is not zero-value either => ok must be true at element " "
}
}
{
// more precisely: explicit type testing
x, ok := FirstNonZero(0, 0, 10, 20)
if !ok || x != 10 {
t.Fatalf("FirstNonZero int got=(%d,%v) want (10,true)", x, ok)
}
}
{
s, ok := FirstNonZero("", "abc", "xyz")
if !ok || s != "abc" {
t.Fatalf("FirstNonZero string got=(%q,%v) want (\"abc\",true)", s, ok)
}
}
{
_, ok := FirstNonZero[int]() // none
if ok {
t.Fatalf("FirstNonZero empty should be (0,false)")
}
}
}
func TestOrElse(t *testing.T) {
if got := OrElse("", "def"); got != "def" {
t.Fatalf("OrElse(\"\",def) got=%q want def", got)
}
if got := OrElse("val", "def"); got != "val" {
t.Fatalf("OrElse(\"val\",def) got=%q want val", got)
}
}
func TestOrElseFn_Lazy(t *testing.T) {
call := 0
def := func() int { call++; return 99 }
if got := OrElseFn(0, def); got != 99 || call != 1 {
t.Fatalf("OrElseFn(0) got=%d call=%d want 99/1", got, call)
}
call = 0
if got := OrElseFn(5, def); got != 5 || call != 0 {
t.Fatalf("OrElseFn(5) got=%d call=%d want 5/0", got, call)
}
}
func TestPtrOr(t *testing.T) {
var p *int
if got := PtrOr(p, 42); got != 42 {
t.Fatalf("PtrOr(nil,42) = %d want 42", got)
}
v := 7
p = &v
if got := PtrOr(p, 42); got != 7 {
t.Fatalf("PtrOr(&7,42) = %d want 7", got)
}
}
func TestPtrOrFn_Lazy(t *testing.T) {
var p *string
call := 0
def := func() string { call++; return "fallback" }
if got := PtrOrFn(p, def); got != "fallback" || call != 1 {
t.Fatalf("PtrOrFn(nil) got=%q call=%d want fallback/1", got, call)
}
s := "ok"
p = &s
call = 0
if got := PtrOrFn(p, def); got != "ok" || call != 0 {
t.Fatalf("PtrOrFn(non-nil) got=%q call=%d want ok/0", got, call)
}
}
func TestPtrCoalesce(t *testing.T) {
a, b, c := 1, 2, 3
tests := []struct {
name string
in []*int
want *int
ok bool
}{
{"all-nil", []*int{nil, nil}, nil, false},
{"first-non-nil", []*int{&a, &b, &c}, &a, true},
{"middle-non-nil", []*int{nil, &b, &c}, &b, true},
{"last-non-nil", []*int{nil, nil, &c}, &c, true},
}
for _, tt := range tests {
got, ok := PtrCoalesce(tt.in...)
if ok != tt.ok {
t.Fatalf("%s ok=%v want %v", tt.name, ok, tt.ok)
}
if ok && *got != *tt.want {
t.Fatalf("%s got=%d want %d", tt.name, *got, *tt.want)
}
}
}
// =============== Match / Case / Default ===============
func TestMatch_Basic(t *testing.T) {
role := "admin"
perm := Match[string, int](role).
Case("root", 4).
Case("admin", 3).
Default(1)
if perm != 3 {
t.Fatalf("Match basic perm=%d want 3", perm)
}
}
func TestMatch_LazyAndPredicates(t *testing.T) {
role := "moderator-x"
calls := 0
perm := Match[string, int](role).
CaseFn("root", func() int { t.Fatal("should not be called"); return 4 }).
CaseWhen(func(r string) bool { return strings.HasPrefix(r, "admin") }, 3).
CaseWhenFn(func(r string) bool { return strings.HasPrefix(r, "moderator") }, func() int { calls++; return 2 }).
Default(1)
if perm != 2 || calls != 1 {
t.Fatalf("Match pred got=%d calls=%d want 2/1", perm, calls)
}
}
func TestMatch_DefaultFnLazy(t *testing.T) {
role := "guest"
calls := 0
perm := Match[string, int](role).
Case("root", 4).
DefaultFn(func() int { calls++; return 1 })
if perm != 1 || calls != 1 {
t.Fatalf("DefaultFn got=%d calls=%d want 1/1", perm, calls)
}
}
// =============== IfErr / IfErrFn / Choose ===============
func TestIfErr(t *testing.T) {
val := IfErr(10, nil, 99)
if val != 10 {
t.Fatalf("IfErr(nil) got=%d want 10", val)
}
val = IfErr(10, errors.New("x"), 99)
if val != 99 {
t.Fatalf("IfErr(err) got=%d want 99", val)
}
}
func TestIfErrFn_Lazy(t *testing.T) {
calls := 0
fb := func(err error) int {
calls++
if err == nil {
t.Fatal("err should not be nil")
}
return 77
}
val := IfErrFn(10, errors.New("boom"), fb)
if val != 77 || calls != 1 {
t.Fatalf("IfErrFn(err) got=%d calls=%d want 77/1", val, calls)
}
calls = 0
val = IfErrFn(10, nil, fb)
if val != 10 || calls != 0 {
t.Fatalf("IfErrFn(nil) got=%d calls=%d want 10/0", val, calls)
}
}
func TestChoose(t *testing.T) {
slowCalled := false
fast := func() (string, bool) { return "", false }
cheap := func() (string, bool) { return "cheap", true }
slow := func() (string, bool) { slowCalled = true; return "slow", true }
got, ok := Choose(fast, cheap, slow)
if !ok || got != "cheap" || slowCalled {
t.Fatalf("Choose got=(%q,%v) slowCalled=%v want (cheap,true)/false", got, ok, slowCalled)
}
got, ok = Choose[string]()
if ok || got != "" {
t.Fatalf("Choose empty got=(%q,%v) want (\"\",false)", got, ok)
}
}
// =============== Examples (also act as tests) ===============
func ExampleT() {
fmt.Println(T(true, "A", "B"))
fmt.Println(T(false, "A", "B"))
// Output:
// A
// B
}
func ExampleTF() {
res := TF[string](
len([]int{1, 2, 3}) > 0,
func() string { return "non-empty" },
func() string { return "empty" },
)
fmt.Println(res)
// Output: non-empty
}
func ExampleWhen() {
score := 77
grade := When[string](score >= 90, "A").
ElseIf(score >= 80, "B").
ElseIf(score >= 70, "C").
Else("D")
fmt.Println(grade)
// Output: C
}
func ExampleMatch() {
role := "moderator"
perm := Match[string, int](role).
Case("root", 4).
Case("admin", 3).
CaseWhen(func(r string) bool { return strings.HasPrefix(r, "mod") }, 2).
Default(1)
fmt.Println(perm)
// Output: 2
}
func ExampleOrElse() {
limit := OrElse(0, 50) // zero-value -> default
name := OrElse("Alice", "Unknown") // non-zero -> itself
fmt.Println(limit, name)
// Output: 50 Alice
}
func ExamplePtrOr() {
var nick *string
name := PtrOr(nick, "Guest")
fmt.Println(name)
// Output: Guest
}
func ExampleIfErrFn() {
load := func() (string, error) { return "", errors.New("boom") }
data, err := load()
out := IfErrFn(data, err, func(e error) string { return "cached" })
fmt.Println(out)
// Output: cached
}
func ExampleChoose() {
val, _ := Choose(
func() (string, bool) { return "", false },
func() (string, bool) { return "first ok", true },
func() (string, bool) { return "never hit", true },
)
fmt.Println(val)
// Output: first ok
}