Len
func Len(expectedLen any) TestDeep
Len is a smuggler operator. It takes data, applies len() function
on it and compares its result to expectedLen. Of course, the
compared value must be an array, a channel, a map, a slice or a
string.
expectedLen can be an int value:
td.Cmp(t, gotSlice, td.Len(12))
as well as an other operator:
td.Cmp(t, gotSlice, td.Len(td.Between(3, 4)))
See also Cap.
See also Len godoc.
Examples
Slice example
t := &testing.T{}
got := []int{11, 22, 33}
ok := td.Cmp(t, got, td.Len(3), "checks %v len is 3", got)
fmt.Println(ok)
ok = td.Cmp(t, got, td.Len(0), "checks %v len is 0", got)
fmt.Println(ok)
got = nil
ok = td.Cmp(t, got, td.Len(0), "checks %v len is 0", got)
fmt.Println(ok)
// Output:
// true
// false
// true
Map example
t := &testing.T{}
got := map[int]bool{11: true, 22: false, 33: false}
ok := td.Cmp(t, got, td.Len(3), "checks %v len is 3", got)
fmt.Println(ok)
ok = td.Cmp(t, got, td.Len(0), "checks %v len is 0", got)
fmt.Println(ok)
got = nil
ok = td.Cmp(t, got, td.Len(0), "checks %v len is 0", got)
fmt.Println(ok)
// Output:
// true
// false
// true
OperatorSlice example
t := &testing.T{}
got := []int{11, 22, 33}
ok := td.Cmp(t, got, td.Len(td.Between(3, 8)),
"checks %v len is in [3 .. 8]", got)
fmt.Println(ok)
ok = td.Cmp(t, got, td.Len(td.Lt(5)), "checks %v len is < 5", got)
fmt.Println(ok)
// Output:
// true
// true
OperatorMap example
t := &testing.T{}
got := map[int]bool{11: true, 22: false, 33: false}
ok := td.Cmp(t, got, td.Len(td.Between(3, 8)),
"checks %v len is in [3 .. 8]", got)
fmt.Println(ok)
ok = td.Cmp(t, got, td.Len(td.Gte(3)), "checks %v len is ≥ 3", got)
fmt.Println(ok)
// Output:
// true
// true
CmpLen shortcut
func CmpLen(t TestingT, got, expectedLen any, args ...any) bool
CmpLen is a shortcut for:
td.Cmp(t, got, td.Len(expectedLen), args...)
See above for details.
Returns true if the test is OK, false if it fails.
If t is a *T then its Config field is inherited.
args… are optional and allow to name the test. This name is
used in case of failure to qualify the test. If len(args) > 1 and
the first item of args is a string and contains a ‘%’ rune then
fmt.Fprintf is used to compose the name, else args are passed to
fmt.Fprint. Do not forget it is the name of the test, not the
reason of a potential failure.
See also CmpLen godoc.
Examples
Slice example
t := &testing.T{}
got := []int{11, 22, 33}
ok := td.CmpLen(t, got, 3, "checks %v len is 3", got)
fmt.Println(ok)
ok = td.CmpLen(t, got, 0, "checks %v len is 0", got)
fmt.Println(ok)
got = nil
ok = td.CmpLen(t, got, 0, "checks %v len is 0", got)
fmt.Println(ok)
// Output:
// true
// false
// true
Map example
t := &testing.T{}
got := map[int]bool{11: true, 22: false, 33: false}
ok := td.CmpLen(t, got, 3, "checks %v len is 3", got)
fmt.Println(ok)
ok = td.CmpLen(t, got, 0, "checks %v len is 0", got)
fmt.Println(ok)
got = nil
ok = td.CmpLen(t, got, 0, "checks %v len is 0", got)
fmt.Println(ok)
// Output:
// true
// false
// true
OperatorSlice example
t := &testing.T{}
got := []int{11, 22, 33}
ok := td.CmpLen(t, got, td.Between(3, 8),
"checks %v len is in [3 .. 8]", got)
fmt.Println(ok)
ok = td.CmpLen(t, got, td.Lt(5), "checks %v len is < 5", got)
fmt.Println(ok)
// Output:
// true
// true
OperatorMap example
t := &testing.T{}
got := map[int]bool{11: true, 22: false, 33: false}
ok := td.CmpLen(t, got, td.Between(3, 8),
"checks %v len is in [3 .. 8]", got)
fmt.Println(ok)
ok = td.CmpLen(t, got, td.Gte(3), "checks %v len is ≥ 3", got)
fmt.Println(ok)
// Output:
// true
// true
T.Len shortcut
func (t *T) Len(got, expectedLen any, args ...any) bool
Len is a shortcut for:
t.Cmp(got, td.Len(expectedLen), args...)
See above for details.
Returns true if the test is OK, false if it fails.
args… are optional and allow to name the test. This name is
used in case of failure to qualify the test. If len(args) > 1 and
the first item of args is a string and contains a ‘%’ rune then
fmt.Fprintf is used to compose the name, else args are passed to
fmt.Fprint. Do not forget it is the name of the test, not the
reason of a potential failure.
See also T.Len godoc.
Examples
Slice example
t := td.NewT(&testing.T{})
got := []int{11, 22, 33}
ok := t.Len(got, 3, "checks %v len is 3", got)
fmt.Println(ok)
ok = t.Len(got, 0, "checks %v len is 0", got)
fmt.Println(ok)
got = nil
ok = t.Len(got, 0, "checks %v len is 0", got)
fmt.Println(ok)
// Output:
// true
// false
// true
Map example
t := td.NewT(&testing.T{})
got := map[int]bool{11: true, 22: false, 33: false}
ok := t.Len(got, 3, "checks %v len is 3", got)
fmt.Println(ok)
ok = t.Len(got, 0, "checks %v len is 0", got)
fmt.Println(ok)
got = nil
ok = t.Len(got, 0, "checks %v len is 0", got)
fmt.Println(ok)
// Output:
// true
// false
// true
OperatorSlice example
t := td.NewT(&testing.T{})
got := []int{11, 22, 33}
ok := t.Len(got, td.Between(3, 8),
"checks %v len is in [3 .. 8]", got)
fmt.Println(ok)
ok = t.Len(got, td.Lt(5), "checks %v len is < 5", got)
fmt.Println(ok)
// Output:
// true
// true
OperatorMap example
t := td.NewT(&testing.T{})
got := map[int]bool{11: true, 22: false, 33: false}
ok := t.Len(got, td.Between(3, 8),
"checks %v len is in [3 .. 8]", got)
fmt.Println(ok)
ok = t.Len(got, td.Gte(3), "checks %v len is ≥ 3", got)
fmt.Println(ok)
// Output:
// true
// true