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How to use ErrorIs method of td Package

Best Go-testdeep code snippet using td.ErrorIs

td_error_is_test.go

Source:td_error_is_test.go

...10	"github.com/maxatome/go-testdeep/internal/dark"11	"github.com/maxatome/go-testdeep/internal/test"12	"github.com/maxatome/go-testdeep/td"13)14func TestErrorIs(t *testing.T) {15	insideErr1 := fmt.Errorf("failure1")16	insideErr2 := fmt.Errorf("failure2: %w", insideErr1)17	insideErr3 := fmt.Errorf("failure3: %w", insideErr2)18	err := fmt.Errorf("failure4: %w", insideErr3)19	checkOK(t, err, td.ErrorIs(err))20	checkOK(t, err, td.ErrorIs(insideErr3))21	checkOK(t, err, td.ErrorIs(insideErr2))22	checkOK(t, err, td.ErrorIs(insideErr1))23	checkOK(t, nil, td.ErrorIs(nil))24	var errNil error25	checkOK(t, &errNil, td.Ptr(td.ErrorIs(nil)))26	checkError(t, nil, td.ErrorIs(insideErr1),27		expectedError{28			Message:  mustBe("nil value"),29			Path:     mustBe("DATA"),30			Got:      mustBe("nil"),31			Expected: mustBe("anything implementing error interface"),32		})33	checkError(t, 45, td.ErrorIs(insideErr1),34		expectedError{35			Message:  mustBe("int does not implement error interface"),36			Path:     mustBe("DATA"),37			Got:      mustBe("45"),38			Expected: mustBe("anything implementing error interface"),39		})40	checkError(t, 45, td.ErrorIs(fmt.Errorf("another")),41		expectedError{42			Message:  mustBe("int does not implement error interface"),43			Path:     mustBe("DATA"),44			Got:      mustBe("45"),45			Expected: mustBe("anything implementing error interface"),46		})47	checkError(t, err, td.ErrorIs(fmt.Errorf("another")),48		expectedError{49			Message:  mustBe("is not the error"),50			Path:     mustBe("DATA"),51			Got:      mustBe(`(*fmt.wrapError) "failure4: failure3: failure2: failure1"`),52			Expected: mustBe(`(*errors.errorString) "another"`),53		})54	checkError(t, err, td.ErrorIs(nil),55		expectedError{56			Message:  mustBe("is not the error"),57			Path:     mustBe("DATA"),58			Got:      mustBe(`(*fmt.wrapError) "failure4: failure3: failure2: failure1"`),59			Expected: mustBe(`nil`),60		})61	type private struct{ err error }62	got := private{err: err}63	for _, expErr := range []error{err, insideErr3} {64		expected := td.Struct(private{}, td.StructFields{"err": td.ErrorIs(expErr)})65		if dark.UnsafeDisabled {66			checkError(t, got, expected,67				expectedError{68					Message: mustBe("cannot compare"),69					Path:    mustBe("DATA.err"),70					Summary: mustBe("unexported field that cannot be overridden"),71				})72		} else {73			checkOK(t, got, expected)74		}75	}76	if !dark.UnsafeDisabled {77		got = private{}78		checkOK(t, got, td.Struct(private{}, td.StructFields{"err": td.ErrorIs(nil)}))79	}80	//81	// String82	test.EqualStr(t, td.ErrorIs(insideErr1).String(), "ErrorIs(failure1)")83	test.EqualStr(t, td.ErrorIs(nil).String(), "ErrorIs(nil)")84}85func TestErrorIsTypeBehind(t *testing.T) {86	equalTypes(t, td.ErrorIs(fmt.Errorf("another")), nil)87}...

td_error_is.go

Source:td_error_is.go

...11	"github.com/maxatome/go-testdeep/internal/ctxerr"12	"github.com/maxatome/go-testdeep/internal/dark"13	"github.com/maxatome/go-testdeep/internal/types"14)15type tdErrorIs struct {16	baseOKNil17	expected error18}19var _ TestDeep = &tdErrorIs{}20func errorToRawString(err error) types.RawString {21	if err == nil {22		return "nil"23	}24	return types.RawString(fmt.Sprintf("(%[1]T) %[1]q", err))25}26// summary(ErrorIs): checks the data is an error and matches a wrapped error27// input(ErrorIs): if(error)28// ErrorIs operator reports whether any error in an error's chain29// matches expected.30//31//	_, err := os.Open("/unknown/file")32//	td.Cmp(t, err, os.ErrNotExist)             // fails33//	td.Cmp(t, err, td.ErrorIs(os.ErrNotExist)) // succeeds34//35//	err1 := fmt.Errorf("failure1")36//	err2 := fmt.Errorf("failure2: %w", err1)37//	err3 := fmt.Errorf("failure3: %w", err2)38//	err := fmt.Errorf("failure4: %w", err3)39//	td.Cmp(t, err, td.ErrorIs(err))  // succeeds40//	td.Cmp(t, err, td.ErrorIs(err1)) // succeeds41//	td.Cmp(t, err1, td.ErrorIs(err)) // fails42//43// Behind the scene it uses [errors.Is] function.44//45// Note that like [errors.Is], expected can be nil: in this case the46// comparison succeeds when got is nil too.47//48// See also [CmpError] and [CmpNoError].49func ErrorIs(expected error) TestDeep {50	return &tdErrorIs{51		baseOKNil: newBaseOKNil(3),52		expected:  expected,53	}54}55func (e *tdErrorIs) Match(ctx ctxerr.Context, got reflect.Value) *ctxerr.Error {56	// nil case57	if !got.IsValid() {58		// Special case59		if e.expected == nil {60			return nil61		}62		if ctx.BooleanError {63			return ctxerr.BooleanError64		}65		return ctx.CollectError(&ctxerr.Error{66			Message:  "nil value",67			Got:      types.RawString("nil"),68			Expected: types.RawString("anything implementing error interface"),69		})70	}71	gotIf, ok := dark.GetInterface(got, true)72	if !ok {73		return ctx.CollectError(ctx.CannotCompareError())74	}75	gotErr, ok := gotIf.(error)76	if !ok {77		if ctx.BooleanError {78			return ctxerr.BooleanError79		}80		return ctx.CollectError(&ctxerr.Error{81			Message:  got.Type().String() + " does not implement error interface",82			Got:      gotIf,83			Expected: types.RawString("anything implementing error interface"),84		})85	}86	if errors.Is(gotErr, e.expected) {87		return nil88	}89	if ctx.BooleanError {90		return ctxerr.BooleanError91	}92	return ctx.CollectError(&ctxerr.Error{93		Message:  "is not the error",94		Got:      errorToRawString(gotErr),95		Expected: errorToRawString(e.expected),96	})97}98func (e *tdErrorIs) String() string {99	if e.expected == nil {100		return "ErrorIs(nil)"101	}102	return "ErrorIs(" + e.expected.Error() + ")"103}...

event_registry_test.go

Source:event_registry_test.go

...16func Test_EventRegistry_Register(t *testing.T) {17	t.Run("factory should return pointer", func(t *testing.T) {18		registry := NewEventRegistry()19		err := registry.Register(factoryBadFn)20		assert.ErrorIs(t, err, ErrFactoryShouldReturnValidPointer)21		err = registry.Register(factoryNilFn)22		assert.ErrorIs(t, err, ErrFactoryShouldReturnValidPointer)23	})24	t.Run("factory should return proper type", func(t *testing.T) {25		registry := NewEventRegistry()26		err := registry.Register(factoryFn)27		assert.NoError(t, err)28		assert.Len(t, registry.factories, 1)29		td, err := registry.Create(registry.GetName(&eventRegistryTestData{}))30		assert.NoError(t, err)31		assert.IsType(t, &eventRegistryTestData{}, td)32	})33	t.Run("should not register duplicate factories", func(t *testing.T) {34		registry := NewEventRegistry()35		_ = registry.Register(factoryFn)36		err := registry.Register(factoryFn)37		assert.NoError(t, err)38		assert.Len(t, registry.factories, 1)39	})40}41func Test_EventRegistry_Unregister(t *testing.T) {42	t.Run("should return early if type not registered", func(t *testing.T) {43		registry := NewEventRegistry()44		registry.Unregister(&eventRegistryTestData{})45		assert.Len(t, registry.factories, 0)46	})47	t.Run("should remove factory", func(t *testing.T) {48		registry := NewEventRegistry()49		_ = registry.Register(factoryFn)50		registry.Unregister(factoryFn())51		assert.Len(t, registry.factories, 0)52	})53}54func Test_EventRegistry_Create(t *testing.T) {55	t.Run("should return error when type not registered", func(t *testing.T) {56		registry := NewEventRegistry()57		_, err := registry.Create("poo")58		assert.ErrorIs(t, err, ErrEventDataFactoryNotRegistered)59	})60	t.Run("should return pointer", func(t *testing.T) {61		registry := NewEventRegistry()62		_ = registry.Register(factoryFn)63		ptr, err := registry.Create(registry.GetName(factoryFn()))64		assert.NoError(t, err)65		assert.IsType(t, &eventRegistryTestData{}, ptr)66	})67}68func Test_dn(t *testing.T) {69	n1 := defaultNameFormatter(eventRegistryTestData{})70	n2 := defaultNameFormatter(&eventRegistryTestData{})71	fmt.Println(n1)72	fmt.Println(n2)...

ErrorIs

Using AI Code Generation

1import (2func main() {3	err1 := errors.New("Error 1")4	err2 := fmt.Errorf("Error 2: %w", err1)5	err3 := fmt.Errorf("Error 3: %w", err2)6	err4 := fmt.Errorf("Error 4: %w", err3)7	fmt.Println(errors.Is(err4, err1))8	fmt.Println(errors.Is(err4, err2))9	fmt.Println(errors.Is(err4, err3))10	fmt.Println(errors.Is(err4, err4))11}

ErrorIs

Using AI Code Generation

1import (2func main() {3	err1 := errors.New("error 1")4	err2 := errors.New("error 2")5	err3 := fmt.Errorf("error 3: %w", err2)6	err4 := fmt.Errorf("error 4: %w", err3)7	err5 := fmt.Errorf("error 5: %w", err1)8	err6 := fmt.Errorf("error 6: %w", err5)9	fmt.Println(errors.Is(err4, err2))10	fmt.Println(errors.Is(err4, err1))11	fmt.Println(errors.Is(err6, err1))12}

ErrorIs

Using AI Code Generation

1import (2func main() {3	var err1 error = errors.New("Error 1")4	var err2 error = errors.New("Error 2")5	var err3 error = errors.New("Error 3")6	fmt.Println(errors.Is(err1, err2))7	fmt.Println(errors.Is(err1, err1))8	fmt.Println(errors.Is(err1, err3))9}

ErrorIs

Using AI Code Generation

1import (2func main() {3	err1 := errors.New("error 1")4	err2 := errors.New("error 2")5	err3 := fmt.Errorf("error 2: %w", err2)6	fmt.Println(errors.Is(err1, err2))7	fmt.Println(errors.Is(err3, err2))8}

ErrorIs

Using AI Code Generation

1import (2func main() {3	f, err := os.Open("test.txt")4	if err != nil {5		log.Fatal(err)6	}7	fmt.Println(f.Name(), "opened successfully")8}

ErrorIs

Using AI Code Generation

1import (2func main() {3	err := errors.New("Error")4	fmt.Println(errors.Is(err, err))5	fmt.Println(errors.Is(err, errors.New("Error")))6	fmt.Println(errors.Is(err, errors.New("Error1")))7}

ErrorIs

Using AI Code Generation

1import (2func main() {3	e1 := errors.New("e1")4	e2 := errors.New("e2")5	e3 := errors.New("e3")6	fmt.Println(errors.Is(e1, e1))7	fmt.Println(errors.Is(e1, e2))8	fmt.Println(errors.Is(e1, e3))9}

ErrorIs

Using AI Code Generation

1import (2func main() {3	err1 := errors.New("Error1")4	err2 := errors.New("Error2")5	err3 := errors.New("Error3")6	fmt.Println(errors.Is(err1, err2))7	fmt.Println(errors.Is(err1, err1))8	fmt.Println(errors.Is(err2, err3))9}

ErrorIs

Using AI Code Generation

1import (2func main() {3	var err error = errors.New("Error")4	var err1 error = fmt.Errorf("Error1")5	fmt.Println(errors.Is(err, err1))6}

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