HasPrefix
func HasPrefix(expected string) TestDeep
HasPrefix operator allows to compare the prefix of a string (or
convertible), []byte (or convertible), error or fmt.Stringer
interface (error interface is tested before fmt.Stringer).
td.Cmp(t, []byte("foobar"), td.HasPrefix("foo")) // succeeds
type Foobar string
td.Cmp(t, Foobar("foobar"), td.HasPrefix("foo")) // succeeds
err := errors.New("error!")
td.Cmp(t, err, td.HasPrefix("err")) // succeeds
bstr := bytes.NewBufferString("fmt.Stringer!")
td.Cmp(t, bstr, td.HasPrefix("fmt")) // succeeds
See also Contains, HasSuffix, Re, ReAll and String.
See also HasPrefix godoc.
Examples
Base example
t := &testing.T{}
got := "foobar"
ok := td.Cmp(t, got, td.HasPrefix("foo"), "checks %s", got)
fmt.Println("using string:", ok)
ok = td.Cmp(t, []byte(got), td.HasPrefix("foo"), "checks %s", got)
fmt.Println("using []byte:", ok)
// Output:
// using string: true
// using []byte: true
Stringer example
t := &testing.T{}
// bytes.Buffer implements fmt.Stringer
got := bytes.NewBufferString("foobar")
ok := td.Cmp(t, got, td.HasPrefix("foo"), "checks %s", got)
fmt.Println(ok)
// Output:
// true
Error example
t := &testing.T{}
got := errors.New("foobar")
ok := td.Cmp(t, got, td.HasPrefix("foo"), "checks %s", got)
fmt.Println(ok)
// Output:
// true
CmpHasPrefix shortcut
func CmpHasPrefix(t TestingT, got any, expected string, args ...any) bool
CmpHasPrefix is a shortcut for:
td.Cmp(t, got, td.HasPrefix(expected), 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 CmpHasPrefix godoc.
Examples
Base example
t := &testing.T{}
got := "foobar"
ok := td.CmpHasPrefix(t, got, "foo", "checks %s", got)
fmt.Println("using string:", ok)
ok = td.Cmp(t, []byte(got), td.HasPrefix("foo"), "checks %s", got)
fmt.Println("using []byte:", ok)
// Output:
// using string: true
// using []byte: true
Stringer example
t := &testing.T{}
// bytes.Buffer implements fmt.Stringer
got := bytes.NewBufferString("foobar")
ok := td.CmpHasPrefix(t, got, "foo", "checks %s", got)
fmt.Println(ok)
// Output:
// true
Error example
t := &testing.T{}
got := errors.New("foobar")
ok := td.CmpHasPrefix(t, got, "foo", "checks %s", got)
fmt.Println(ok)
// Output:
// true
T.HasPrefix shortcut
func (t *T) HasPrefix(got any, expected string, args ...any) bool
HasPrefix is a shortcut for:
t.Cmp(got, td.HasPrefix(expected), 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.HasPrefix godoc.
Examples
Base example
t := td.NewT(&testing.T{})
got := "foobar"
ok := t.HasPrefix(got, "foo", "checks %s", got)
fmt.Println("using string:", ok)
ok = t.Cmp([]byte(got), td.HasPrefix("foo"), "checks %s", got)
fmt.Println("using []byte:", ok)
// Output:
// using string: true
// using []byte: true
Stringer example
t := td.NewT(&testing.T{})
// bytes.Buffer implements fmt.Stringer
got := bytes.NewBufferString("foobar")
ok := t.HasPrefix(got, "foo", "checks %s", got)
fmt.Println(ok)
// Output:
// true
Error example
t := td.NewT(&testing.T{})
got := errors.New("foobar")
ok := t.HasPrefix(got, "foo", "checks %s", got)
fmt.Println(ok)
// Output:
// true