Re

func Re(reg any, capture ...any) TestDeep

Re operator allows to apply a regexp on a string (or convertible), []byte, error or fmt.Stringer interface (error interface is tested before fmt.Stringer.)

reg is the regexp. It can be a string that is automatically compiled using regexp.Compile, or a *regexp.Regexp.

Optional capture parameter can be used to match the contents of regexp groups. Groups are presented as a []string or [][]byte depending the original matched data. Note that an other operator can be used here.

td.Cmp(t, "foobar zip!", td.Re(`^foobar`)) // succeeds
td.Cmp(t, "John Doe",
  td.Re(`^(\w+) (\w+)`, []string{"John", "Doe"})) // succeeds
td.Cmp(t, "John Doe",
  td.Re(`^(\w+) (\w+)`, td.Bag("Doe", "John"))) // succeeds

When matching many, many lines with a single regexp, it is sometimes difficult to see where the regexp failed in the input string. To avoid that, the regexp can be split by lines and so the failure is easier to locate, thanks to List operator and Flatten:

td.Cmp(t,
  strings.Split(got, "\n"),
  td.List(td.Flatten(strings.Split(expectedRe, "\n"),
    func(line string) any {
      return `^` + td.Re(line) + `\z`
    })))

See also the multilines example.

Examples

Base example

	t := &testing.T{}

	got := "foo bar"
	ok := td.Cmp(t, got, td.Re("(zip|bar)$"), "checks value %s", got)
	fmt.Println(ok)

	got = "bar foo"
	ok = td.Cmp(t, got, td.Re("(zip|bar)$"), "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true
	// false

Stringer example

	t := &testing.T{}

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foo bar")
	ok := td.Cmp(t, got, td.Re("(zip|bar)$"), "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true

Error example

	t := &testing.T{}

	got := errors.New("foo bar")
	ok := td.Cmp(t, got, td.Re("(zip|bar)$"), "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true

Capture example

	t := &testing.T{}

	got := "foo bar biz"
	ok := td.Cmp(t, got, td.Re(`^(\w+) (\w+) (\w+)$`, td.Set("biz", "foo", "bar")),
		"checks value %s", got)
	fmt.Println(ok)

	got = "foo bar! biz"
	ok = td.Cmp(t, got, td.Re(`^(\w+) (\w+) (\w+)$`, td.Set("biz", "foo", "bar")),
		"checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true
	// false

Multilines example

	t := &testing.T{}

	got := `multi
lines
probably
more
than 4
`
	expectedRe := `^multi
lines?
(probably|possibly)
more
than \d+
\z`

	ok := td.Cmp(t, got, td.Re(expectedRe))
	fmt.Println("Raw multi-lines string matches:", ok)

	// But for strings with many, many, many lines, when the regexp
	// doesn't match, it is sometimes difficult to see where the regexp
	// failed in the string. Here td.List & td.Flatten can help to apply
	// regexp line per line (note expectedRe is not anchored anymore):
	expectedRe = `multi
lines?
(probably|possibly)
more
than \d+
`
	ok = td.Cmp(t,
		strings.Split(got, "\n"),
		td.List(td.Flatten(strings.Split(expectedRe, "\n"),
			func(line string) any {
				return td.Re(`^` + line + `\z`)
			})))
	fmt.Println("All string lines match:", ok)

	// Output:
	// Raw multi-lines string matches: true
	// All string lines match: true

Compiled example

	t := &testing.T{}

	expected := regexp.MustCompile("(zip|bar)$")

	got := "foo bar"
	ok := td.Cmp(t, got, td.Re(expected), "checks value %s", got)
	fmt.Println(ok)

	got = "bar foo"
	ok = td.Cmp(t, got, td.Re(expected), "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true
	// false

CompiledStringer example

	t := &testing.T{}

	expected := regexp.MustCompile("(zip|bar)$")

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foo bar")
	ok := td.Cmp(t, got, td.Re(expected), "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true

CompiledError example

	t := &testing.T{}

	expected := regexp.MustCompile("(zip|bar)$")

	got := errors.New("foo bar")
	ok := td.Cmp(t, got, td.Re(expected), "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true

CompiledCapture example

	t := &testing.T{}

	expected := regexp.MustCompile(`^(\w+) (\w+) (\w+)$`)

	got := "foo bar biz"
	ok := td.Cmp(t, got, td.Re(expected, td.Set("biz", "foo", "bar")),
		"checks value %s", got)
	fmt.Println(ok)

	got = "foo bar! biz"
	ok = td.Cmp(t, got, td.Re(expected, td.Set("biz", "foo", "bar")),
		"checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true
	// false

CmpRe shortcut

func CmpRe(t TestingT, got, reg , capture any, args ...any) bool

CmpRe is a shortcut for:

td.Cmp(t, got, td.Re(reg, capture), args...)

See above for details.

Re optional parameter capture is here mandatory. nil value should be passed to mimic its absence in original Re call.

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 CmpRe godoc.

Examples

Base example

	t := &testing.T{}

	got := "foo bar"
	ok := td.CmpRe(t, got, "(zip|bar)$", nil, "checks value %s", got)
	fmt.Println(ok)

	got = "bar foo"
	ok = td.CmpRe(t, got, "(zip|bar)$", nil, "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true
	// false

Stringer example

	t := &testing.T{}

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foo bar")
	ok := td.CmpRe(t, got, "(zip|bar)$", nil, "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true

Error example

	t := &testing.T{}

	got := errors.New("foo bar")
	ok := td.CmpRe(t, got, "(zip|bar)$", nil, "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true

Capture example

	t := &testing.T{}

	got := "foo bar biz"
	ok := td.CmpRe(t, got, `^(\w+) (\w+) (\w+)$`, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

	got = "foo bar! biz"
	ok = td.CmpRe(t, got, `^(\w+) (\w+) (\w+)$`, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true
	// false

Multilines example

	t := &testing.T{}

	got := `multi
lines
probably
more
than 4
`
	expectedRe := `^multi
lines?
(probably|possibly)
more
than \d+
\z`

	ok := td.CmpRe(t, got, expectedRe, nil)
	fmt.Println("Raw multi-lines string matches:", ok)

	// But for strings with many, many, many lines, when the regexp
	// doesn't match, it is sometimes difficult to see where the regexp
	// failed in the string. Here td.List & td.Flatten can help to apply
	// regexp line per line (note expectedRe is not anchored anymore):
	expectedRe = `multi
lines?
(probably|possibly)
more
than \d+
`
	ok = td.Cmp(t,
		strings.Split(got, "\n"),
		td.List(td.Flatten(strings.Split(expectedRe, "\n"),
			func(line string) any {
				return td.Re(`^` + line + `\z`)
			})))
	fmt.Println("All string lines match:", ok)

	// Output:
	// Raw multi-lines string matches: true
	// All string lines match: true

Compiled example

	t := &testing.T{}

	expected := regexp.MustCompile("(zip|bar)$")

	got := "foo bar"
	ok := td.CmpRe(t, got, expected, nil, "checks value %s", got)
	fmt.Println(ok)

	got = "bar foo"
	ok = td.CmpRe(t, got, expected, nil, "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true
	// false

CompiledStringer example

	t := &testing.T{}

	expected := regexp.MustCompile("(zip|bar)$")

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foo bar")
	ok := td.CmpRe(t, got, expected, nil, "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true

CompiledError example

	t := &testing.T{}

	expected := regexp.MustCompile("(zip|bar)$")

	got := errors.New("foo bar")
	ok := td.CmpRe(t, got, expected, nil, "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true

CompiledCapture example

	t := &testing.T{}

	expected := regexp.MustCompile(`^(\w+) (\w+) (\w+)$`)

	got := "foo bar biz"
	ok := td.CmpRe(t, got, expected, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

	got = "foo bar! biz"
	ok = td.CmpRe(t, got, expected, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true
	// false

T.Re shortcut

func (t *T) Re(got, reg , capture any, args ...any) bool

Re is a shortcut for:

t.Cmp(got, td.Re(reg, capture), args...)

See above for details.

Re optional parameter capture is here mandatory. nil value should be passed to mimic its absence in original Re call.

Returns true if the test is OK, false if it fails.

See also T.Re godoc.

Examples

Base example

	t := td.NewT(&testing.T{})

	got := "foo bar"
	ok := t.Re(got, "(zip|bar)$", nil, "checks value %s", got)
	fmt.Println(ok)

	got = "bar foo"
	ok = t.Re(got, "(zip|bar)$", nil, "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true
	// false

Stringer example

	t := td.NewT(&testing.T{})

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foo bar")
	ok := t.Re(got, "(zip|bar)$", nil, "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true

Error example

	t := td.NewT(&testing.T{})

	got := errors.New("foo bar")
	ok := t.Re(got, "(zip|bar)$", nil, "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true

Capture example

	t := td.NewT(&testing.T{})

	got := "foo bar biz"
	ok := t.Re(got, `^(\w+) (\w+) (\w+)$`, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

	got = "foo bar! biz"
	ok = t.Re(got, `^(\w+) (\w+) (\w+)$`, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true
	// false

Multilines example

	t := td.NewT(&testing.T{})

	got := `multi
lines
probably
more
than 4
`
	expectedRe := `^multi
lines?
(probably|possibly)
more
than \d+
\z`

	ok := t.Re(got, expectedRe, nil)
	fmt.Println("Raw multi-lines string matches:", ok)

	// But for strings with many, many, many lines, when the regexp
	// doesn't match, it is sometimes difficult to see where the regexp
	// failed in the string. Here td.List & td.Flatten can help to apply
	// regexp line per line (note expectedRe is not anchored anymore):
	expectedRe = `multi
lines?
(probably|possibly)
more
than \d+
`
	ok = t.Cmp(
		strings.Split(got, "\n"),
		td.List(td.Flatten(strings.Split(expectedRe, "\n"),
			func(line string) any {
				return td.Re(`^` + line + `\z`)
			})))
	fmt.Println("All string lines match:", ok)

	// Output:
	// Raw multi-lines string matches: true
	// All string lines match: true

Compiled example

	t := td.NewT(&testing.T{})

	expected := regexp.MustCompile("(zip|bar)$")

	got := "foo bar"
	ok := t.Re(got, expected, nil, "checks value %s", got)
	fmt.Println(ok)

	got = "bar foo"
	ok = t.Re(got, expected, nil, "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true
	// false

CompiledStringer example

	t := td.NewT(&testing.T{})

	expected := regexp.MustCompile("(zip|bar)$")

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foo bar")
	ok := t.Re(got, expected, nil, "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true

CompiledError example

	t := td.NewT(&testing.T{})

	expected := regexp.MustCompile("(zip|bar)$")

	got := errors.New("foo bar")
	ok := t.Re(got, expected, nil, "checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true

CompiledCapture example

	t := td.NewT(&testing.T{})

	expected := regexp.MustCompile(`^(\w+) (\w+) (\w+)$`)

	got := "foo bar biz"
	ok := t.Re(got, expected, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

	got = "foo bar! biz"
	ok = t.Re(got, expected, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

	// Output:
	// true
	// false