testutils

func And ¶

func And(ms ...types.GomegaMatcher) types.GomegaMatcher

And succeeds only if all of the given matchers succeed. The matchers are tried in order, and will fail-fast if one doesn't succeed.

Expect("hi").To(And(HaveLen(2), Equal("hi"))

And(), Or(), Not() and WithTransform() allow matchers to be composed into complex expressions.

func BeADirectory ¶

func BeADirectory() types.GomegaMatcher

BeADirectory succeeds if a file exists and is a directory. Actual must be a string representing the abs path to the file being checked.

func BeARegularFile ¶

func BeARegularFile() types.GomegaMatcher

BeARegularFile succeeds if a file exists and is a regular file. Actual must be a string representing the abs path to the file being checked.

func BeAnExistingFile ¶

func BeAnExistingFile() types.GomegaMatcher

BeAnExistingFile succeeds if a file exists. Actual must be a string representing the abs path to the file being checked.

func BeAssignableToTypeOf ¶

func BeAssignableToTypeOf(expected interface{}) types.GomegaMatcher

BeAssignableToTypeOf succeeds if actual is assignable to the type of expected. It will return an error when one of the values is nil.

Expect(0).Should(BeAssignableToTypeOf(0))         // Same values
Expect(5).Should(BeAssignableToTypeOf(-1))        // different values same type
Expect("foo").Should(BeAssignableToTypeOf("bar")) // different values same type
Expect(struct{ Foo string }{}).Should(BeAssignableToTypeOf(struct{ Foo string }{}))

func BeClosed ¶

func BeClosed() types.GomegaMatcher

BeClosed succeeds if actual is a closed channel. It is an error to pass a non-channel to BeClosed, it is also an error to pass nil

In order to check whether or not the channel is closed, Gomega must try to read from the channel (even in the `ShouldNot(BeClosed())` case). You should keep this in mind if you wish to make subsequent assertions about values coming down the channel.

Also, if you are testing that a *buffered* channel is closed you must first read all values out of the channel before asserting that it is closed (it is not possible to detect that a buffered-channel has been closed until all its buffered values are read).

Finally, as a corollary: it is an error to check whether or not a send-only channel is closed.

func BeComparableTo ¶

func BeComparableTo(expected interface{}, opts ...cmp.Option) types.GomegaMatcher

BeComparableTo uses gocmp.Equal from github.com/google/go-cmp (instead of reflect.DeepEqual) to perform a deep comparison. You can pass cmp.Option as options. It is an error for actual and expected to be nil. Use BeNil() instead.

func BeElementOf ¶

func BeElementOf(elements ...interface{}) types.GomegaMatcher

BeElementOf succeeds if actual is contained in the passed in elements. BeElementOf() always uses Equal() to perform the match. When the passed in elements are comprised of a single element that is either an Array or Slice, BeElementOf() behaves as the reverse of ContainElement() that operates with Equal() to perform the match.

Expect(2).Should(BeElementOf([]int{1, 2}))
Expect(2).Should(BeElementOf([2]int{1, 2}))

Otherwise, BeElementOf() provides a syntactic sugar for Or(Equal(_), Equal(_), ...):

Expect(2).Should(BeElementOf(1, 2))

Actual must be typed.

func BeEmpty ¶

func BeEmpty() types.GomegaMatcher

BeEmpty succeeds if actual is empty. Actual must be of type string, array, map, chan, or slice.

func BeEquivalentTo ¶

func BeEquivalentTo(expected interface{}) types.GomegaMatcher

BeEquivalentTo is more lax than Equal, allowing equality between different types. This is done by converting actual to have the type of expected before attempting equality with reflect.DeepEqual. It is an error for actual and expected to be nil. Use BeNil() instead.

func BeFalse ¶

func BeFalse() types.GomegaMatcher

BeFalse succeeds if actual is false

In general, it's better to use `BeFalseBecause(reason)` to provide a more useful error message if a false check fails.

func BeFalseBecause ¶

func BeFalseBecause(format string, args ...any) types.GomegaMatcher

BeFalseBecause succeeds if actual is false and displays the provided reason if it is true. fmt.Sprintf is used to render the reason

func BeIdenticalTo ¶

func BeIdenticalTo(expected interface{}) types.GomegaMatcher

BeIdenticalTo uses the == operator to compare actual with expected. BeIdenticalTo is strict about types when performing comparisons. It is an error for both actual and expected to be nil. Use BeNil() instead.

func BeKeyOf ¶

func BeKeyOf(element interface{}) types.GomegaMatcher

BeKeyOf succeeds if actual is contained in the keys of the passed in map. BeKeyOf() always uses Equal() to perform the match between actual and the map keys.

Expect("foo").Should(BeKeyOf(map[string]bool{"foo": true, "bar": false}))

func BeNil ¶

func BeNil() types.GomegaMatcher

BeNil succeeds if actual is nil

func BeNumerically ¶

func BeNumerically(comparator string, compareTo ...interface{}) types.GomegaMatcher

BeNumerically performs numerical assertions in a type-agnostic way. Actual and expected should be numbers, though the specific type of number is irrelevant (float32, float64, uint8, etc...).

There are six, self-explanatory, supported comparators:

Expect(1.0).Should(BeNumerically("==", 1))
Expect(1.0).Should(BeNumerically("~", 0.999, 0.01))
Expect(1.0).Should(BeNumerically(">", 0.9))
Expect(1.0).Should(BeNumerically(">=", 1.0))
Expect(1.0).Should(BeNumerically("<", 3))
Expect(1.0).Should(BeNumerically("<=", 1.0))

func BeSent ¶

func BeSent(arg interface{}) types.GomegaMatcher

BeSent succeeds if a value can be sent to actual. Actual must be a channel (and cannot be a receive-only channel) that can sent the type of the value passed into BeSent -- anything else is an error. In addition, actual must not be closed.

BeSent never blocks:

- If the channel `c` is not ready to receive then Expect(c).Should(BeSent("foo")) will fail immediately - If the channel `c` is eventually ready to receive then Eventually(c).Should(BeSent("foo")) will succeed.. presuming the channel becomes ready to receive before Eventually's timeout - If the channel `c` is closed then Expect(c).Should(BeSent("foo")) and Ω(c).ShouldNot(BeSent("foo")) will both fail immediately

Of course, the value is actually sent to the channel. The point of `BeSent` is less to make an assertion about the availability of the channel (which is typically an implementation detail that your test should not be concerned with). Rather, the point of `BeSent` is to make it possible to easily and expressively write tests that can timeout on blocked channel sends.

func BeTemporally ¶

func BeTemporally(comparator string, compareTo time.Time, threshold ...time.Duration) types.GomegaMatcher

BeTemporally compares time.Time's like BeNumerically Actual and expected must be time.Time. The comparators are the same as for BeNumerically

Expect(time.Now()).Should(BeTemporally(">", time.Time{}))
Expect(time.Now()).Should(BeTemporally("~", time.Now(), time.Second))

func BeTrue ¶

func BeTrue() types.GomegaMatcher

BeTrue succeeds if actual is true

In general, it's better to use `BeTrueBecause(reason)` to provide a more useful error message if a true check fails.

func BeTrueBecause ¶

func BeTrueBecause(format string, args ...any) types.GomegaMatcher

BeTrueBecause succeeds if actual is true and displays the provided reason if it is false fmt.Sprintf is used to render the reason

func BeZero ¶

func BeZero() types.GomegaMatcher

BeZero succeeds if actual is the zero value for its type or if actual is nil.

func ConsistOf ¶

func ConsistOf(elements ...interface{}) types.GomegaMatcher

ConsistOf succeeds if actual contains precisely the elements passed into the matcher. The ordering of the elements does not matter. By default ConsistOf() uses Equal() to match the elements, however custom matchers can be passed in instead. Here are some examples:

Expect([]string{"Foo", "FooBar"}).Should(ConsistOf("FooBar", "Foo"))
Expect([]string{"Foo", "FooBar"}).Should(ConsistOf(ContainSubstring("Bar"), "Foo"))
Expect([]string{"Foo", "FooBar"}).Should(ConsistOf(ContainSubstring("Foo"), ContainSubstring("Foo")))

Actual must be an array, slice or map. For maps, ConsistOf matches against the map's values.

You typically pass variadic arguments to ConsistOf (as in the examples above). However, if you need to pass in a slice you can provided that it is the only element passed in to ConsistOf:

Expect([]string{"Foo", "FooBar"}).Should(ConsistOf([]string{"FooBar", "Foo"}))

Note that Go's type system does not allow you to write this as ConsistOf([]string{"FooBar", "Foo"}...) as []string and []interface{} are different types - hence the need for this special rule.

func ContainElement ¶

func ContainElement(element interface{}, result ...interface{}) types.GomegaMatcher

ContainElement succeeds if actual contains the passed in element. By default ContainElement() uses Equal() to perform the match, however a matcher can be passed in instead:

Expect([]string{"Foo", "FooBar"}).Should(ContainElement(ContainSubstring("Bar")))

Actual must be an array, slice or map. For maps, ContainElement searches through the map's values.

If you want to have a copy of the matching element(s) found you can pass a pointer to a variable of the appropriate type. If the variable isn't a slice or map, then exactly one match will be expected and returned. If the variable is a slice or map, then at least one match is expected and all matches will be stored in the variable.

var findings []string
Expect([]string{"Foo", "FooBar"}).Should(ContainElement(ContainSubString("Bar", &findings)))

func ContainElements ¶

func ContainElements(elements ...interface{}) types.GomegaMatcher

ContainElements succeeds if actual contains the passed in elements. The ordering of the elements does not matter. By default ContainElements() uses Equal() to match the elements, however custom matchers can be passed in instead. Here are some examples:

Expect([]string{"Foo", "FooBar"}).Should(ContainElements("FooBar"))
Expect([]string{"Foo", "FooBar"}).Should(ContainElements(ContainSubstring("Bar"), "Foo"))

Actual must be an array, slice or map. For maps, ContainElements searches through the map's values.

func ContainSubstring ¶

func ContainSubstring(substr string, args ...interface{}) types.GomegaMatcher

ContainSubstring succeeds if actual is a string or stringer that contains the passed-in substring. Optional arguments can be provided to construct the substring via fmt.Sprintf().

func Equal ¶

func Equal(expected interface{}) types.GomegaMatcher

Equal uses reflect.DeepEqual to compare actual with expected. Equal is strict about types when performing comparisons. It is an error for both actual and expected to be nil. Use BeNil() instead.

func HaveCap ¶

func HaveCap(count int) types.GomegaMatcher

HaveCap succeeds if actual has the passed-in capacity. Actual must be of type array, chan, or slice.

func HaveEach ¶

func HaveEach(element interface{}) types.GomegaMatcher

HaveEach succeeds if actual solely contains elements that match the passed in element. Please note that if actual is empty, HaveEach always will fail. By default HaveEach() uses Equal() to perform the match, however a matcher can be passed in instead:

Expect([]string{"Foo", "FooBar"}).Should(HaveEach(ContainSubstring("Foo")))

Actual must be an array, slice or map. For maps, HaveEach searches through the map's values.

func HaveExactElements ¶

func HaveExactElements(elements ...interface{}) types.GomegaMatcher

HaveExactElements succeeds if actual contains elements that precisely match the elemets passed into the matcher. The ordering of the elements does matter. By default HaveExactElements() uses Equal() to match the elements, however custom matchers can be passed in instead. Here are some examples:

Expect([]string{"Foo", "FooBar"}).Should(HaveExactElements("Foo", "FooBar"))
Expect([]string{"Foo", "FooBar"}).Should(HaveExactElements("Foo", ContainSubstring("Bar")))
Expect([]string{"Foo", "FooBar"}).Should(HaveExactElements(ContainSubstring("Foo"), ContainSubstring("Foo")))

Actual must be an array or slice.

func HaveExistingField ¶

func HaveExistingField(field string) types.GomegaMatcher

HaveExistingField succeeds if actual is a struct and the specified field exists.

HaveExistingField can be combined with HaveField in order to cover use cases with optional fields. HaveField alone would trigger an error in such situations.

Expect(MrHarmless).NotTo(And(HaveExistingField("Title"), HaveField("Title", "Supervillain")))

func HaveField ¶

func HaveField(field string, expected interface{}) types.GomegaMatcher

HaveField succeeds if actual is a struct and the value at the passed in field matches the passed in matcher. By default HaveField used Equal() to perform the match, however a matcher can be passed in in stead.

The field must be a string that resolves to the name of a field in the struct. Structs can be traversed using the '.' delimiter. If the field ends with '()' a method named field is assumed to exist on the struct and is invoked. Such methods must take no arguments and return a single value:

type Book struct {
    Title string
    Author Person
}
type Person struct {
    FirstName string
    LastName string
    DOB time.Time
}
Expect(book).To(HaveField("Title", "Les Miserables"))
Expect(book).To(HaveField("Title", ContainSubstring("Les"))
Expect(book).To(HaveField("Author.FirstName", Equal("Victor"))
Expect(book).To(HaveField("Author.DOB.Year()", BeNumerically("<", 1900))

func HaveHTTPBody ¶

func HaveHTTPBody(expected interface{}) types.GomegaMatcher

HaveHTTPBody matches if the body matches. Actual must be either a *http.Response or *httptest.ResponseRecorder. Expected must be either a string, []byte, or other matcher

func HaveHTTPHeaderWithValue ¶

func HaveHTTPHeaderWithValue(header string, value interface{}) types.GomegaMatcher

HaveHTTPHeaderWithValue succeeds if the header is found and the value matches. Actual must be either a *http.Response or *httptest.ResponseRecorder. Expected must be a string header name, followed by a header value which can be a string, or another matcher.

func HaveHTTPStatus ¶

func HaveHTTPStatus(expected ...interface{}) types.GomegaMatcher

HaveHTTPStatus succeeds if the Status or StatusCode field of an HTTP response matches. Actual must be either a *http.Response or *httptest.ResponseRecorder. Expected must be either an int or a string.

Expect(resp).Should(HaveHTTPStatus(http.StatusOK))   // asserts that resp.StatusCode == 200
Expect(resp).Should(HaveHTTPStatus("404 Not Found")) // asserts that resp.Status == "404 Not Found"
Expect(resp).Should(HaveHTTPStatus(http.StatusOK, http.StatusNoContent))   // asserts that resp.StatusCode == 200 || resp.StatusCode == 204

func HaveKey ¶

func HaveKey(key interface{}) types.GomegaMatcher

HaveKey succeeds if actual is a map with the passed in key. By default HaveKey uses Equal() to perform the match, however a matcher can be passed in instead:

Expect(map[string]string{"Foo": "Bar", "BazFoo": "Duck"}).Should(HaveKey(MatchRegexp(`.+Foo$`)))

func HaveKeyWithValue ¶

func HaveKeyWithValue(key interface{}, value interface{}) types.GomegaMatcher

HaveKeyWithValue succeeds if actual is a map with the passed in key and value. By default HaveKeyWithValue uses Equal() to perform the match, however a matcher can be passed in instead:

Expect(map[string]string{"Foo": "Bar", "BazFoo": "Duck"}).Should(HaveKeyWithValue("Foo", "Bar"))
Expect(map[string]string{"Foo": "Bar", "BazFoo": "Duck"}).Should(HaveKeyWithValue(MatchRegexp(`.+Foo$`), "Bar"))

func HaveLen ¶

func HaveLen(count int) types.GomegaMatcher

HaveLen succeeds if actual has the passed-in length. Actual must be of type string, array, map, chan, or slice.

func HaveOccurred ¶

func HaveOccurred() types.GomegaMatcher

HaveOccurred succeeds if actual is a non-nil error The typical Go error checking pattern looks like:

err := SomethingThatMightFail()
Expect(err).ShouldNot(HaveOccurred())

func HavePrefix ¶

func HavePrefix(prefix string, args ...interface{}) types.GomegaMatcher

HavePrefix succeeds if actual is a string or stringer that contains the passed-in string as a prefix. Optional arguments can be provided to construct via fmt.Sprintf().

func HaveSuffix ¶

func HaveSuffix(suffix string, args ...interface{}) types.GomegaMatcher

HaveSuffix succeeds if actual is a string or stringer that contains the passed-in string as a suffix. Optional arguments can be provided to construct via fmt.Sprintf().

func HaveValue ¶

func HaveValue(matcher types.GomegaMatcher) types.GomegaMatcher

HaveValue applies the given matcher to the value of actual, optionally and repeatedly dereferencing pointers or taking the concrete value of interfaces. Thus, the matcher will always be applied to non-pointer and non-interface values only. HaveValue will fail with an error if a pointer or interface is nil. It will also fail for more than 31 pointer or interface dereferences to guard against mistakenly applying it to arbitrarily deep linked pointers.

HaveValue differs from gstruct.PointTo in that it does not expect actual to be a pointer (as gstruct.PointTo does) but instead also accepts non-pointer and even interface values.

actual := 42
Expect(actual).To(HaveValue(42))
Expect(&actual).To(HaveValue(42))

func Implement ¶

func Implement(expected interface{}) types.GomegaMatcher

Implement checks if the object implements the interface

func MatchError ¶

func MatchError(expected interface{}, functionErrorDescription ...any) types.GomegaMatcher

MatchError succeeds if actual is a non-nil error that matches the passed in string, error, function, or matcher.

These are valid use-cases:

When passed a string:

Expect(err).To(MatchError("an error"))

asserts that err.Error() == "an error"

When passed an error:

Expect(err).To(MatchError(SomeError))

First checks if errors.Is(err, SomeError). If that fails then it checks if reflect.DeepEqual(err, SomeError) repeatedly for err and any errors wrapped by err

When passed a matcher:

Expect(err).To(MatchError(ContainSubstring("sprocket not found")))

the matcher is passed err.Error(). In this case it asserts that err.Error() contains substring "sprocket not found"

When passed a func(err) bool and a description:

Expect(err).To(MatchError(os.IsNotExist, "IsNotExist"))

the function is passed err and matches if the return value is true. The description is required to allow Gomega to print a useful error message.

It is an error for err to be nil or an object that does not implement the Error interface

The optional second argument is a description of the error function, if used. This is required when passing a function but is ignored in all other cases.

func MatchJSON ¶

func MatchJSON(json interface{}) types.GomegaMatcher

MatchJSON succeeds if actual is a string or stringer of JSON that matches the expected JSON. The JSONs are decoded and the resulting objects are compared via reflect.DeepEqual so things like key-ordering and whitespace shouldn't matter.

func MatchRegexp ¶

func MatchRegexp(regexp string, args ...interface{}) types.GomegaMatcher

MatchRegexp succeeds if actual is a string or stringer that matches the passed-in regexp. Optional arguments can be provided to construct a regexp via fmt.Sprintf().

func MatchXML ¶

func MatchXML(xml interface{}) types.GomegaMatcher

MatchXML succeeds if actual is a string or stringer of XML that matches the expected XML. The XMLs are decoded and the resulting objects are compared via reflect.DeepEqual so things like whitespaces shouldn't matter.

func MatchYAML ¶

func MatchYAML(yaml interface{}) types.GomegaMatcher

MatchYAML succeeds if actual is a string or stringer of YAML that matches the expected YAML. The YAML's are decoded and the resulting objects are compared via reflect.DeepEqual so things like key-ordering and whitespace shouldn't matter.

func Not ¶

func Not(matcher types.GomegaMatcher) types.GomegaMatcher

Not negates the given matcher; it succeeds if the given matcher fails.

Expect(1).To(Not(Equal(2))

And(), Or(), Not() and WithTransform() allow matchers to be composed into complex expressions.

func Or ¶

func Or(ms ...types.GomegaMatcher) types.GomegaMatcher

Or succeeds if any of the given matchers succeed. The matchers are tried in order and will return immediately upon the first successful match.

Expect("hi").To(Or(HaveLen(3), HaveLen(2))

And(), Or(), Not() and WithTransform() allow matchers to be composed into complex expressions.

func Panic ¶

func Panic() types.GomegaMatcher

Panic succeeds if actual is a function that, when invoked, panics. Actual must be a function that takes no arguments and returns no results.

func PanicWith ¶

func PanicWith(expected interface{}) types.GomegaMatcher

PanicWith succeeds if actual is a function that, when invoked, panics with a specific value. Actual must be a function that takes no arguments and returns no results.

By default PanicWith uses Equal() to perform the match, however a matcher can be passed in instead:

Expect(fn).Should(PanicWith(MatchRegexp(`.+Foo$`)))

func Receive ¶

func Receive(args ...interface{}) types.GomegaMatcher

Receive succeeds if there is a value to be received on actual. Actual must be a channel (and cannot be a send-only channel) -- anything else is an error.

Receive returns immediately and never blocks:

- If there is nothing on the channel `c` then Expect(c).Should(Receive()) will fail and Ω(c).ShouldNot(Receive()) will pass.

- If the channel `c` is closed then Expect(c).Should(Receive()) will fail and Ω(c).ShouldNot(Receive()) will pass.

- If there is something on the channel `c` ready to be read, then Expect(c).Should(Receive()) will pass and Ω(c).ShouldNot(Receive()) will fail.

If you have a go-routine running in the background that will write to channel `c` you can:

Eventually(c).Should(Receive())

This will timeout if nothing gets sent to `c` (you can modify the timeout interval as you normally do with `Eventually`)

A similar use-case is to assert that no go-routine writes to a channel (for a period of time). You can do this with `Consistently`:

Consistently(c).ShouldNot(Receive())

You can pass `Receive` a matcher. If you do so, it will match the received object against the matcher. For example:

Expect(c).Should(Receive(Equal("foo")))

When given a matcher, `Receive` will always fail if there is nothing to be received on the channel.

Passing Receive a matcher is especially useful when paired with Eventually:

Eventually(c).Should(Receive(ContainSubstring("bar")))

will repeatedly attempt to pull values out of `c` until a value matching "bar" is received.

Finally, if you want to have a reference to the value *sent* to the channel you can pass the `Receive` matcher a pointer to a variable of the appropriate type:

var myThing thing
Eventually(thingChan).Should(Receive(&myThing))
Expect(myThing.Sprocket).Should(Equal("foo"))
Expect(myThing.IsValid()).Should(BeTrue())

func Satisfy ¶

func Satisfy(predicate interface{}) types.GomegaMatcher

Satisfy matches the actual value against the `predicate` function. The given predicate must be a function of one paramter that returns bool.

var isEven = func(i int) bool { return i%2 == 0 }
Expect(2).To(Satisfy(isEven))

func SatisfyAll ¶

func SatisfyAll(matchers ...types.GomegaMatcher) types.GomegaMatcher

SatisfyAll is an alias for And().

Expect("hi").Should(SatisfyAll(HaveLen(2), Equal("hi")))

func SatisfyAny ¶

func SatisfyAny(matchers ...types.GomegaMatcher) types.GomegaMatcher

SatisfyAny is an alias for Or().

Expect("hi").SatisfyAny(Or(HaveLen(3), HaveLen(2))

func Succeed ¶

func Succeed() types.GomegaMatcher

Succeed passes if actual is a nil error Succeed is intended to be used with functions that return a single error value. Instead of

err := SomethingThatMightFail()
Expect(err).ShouldNot(HaveOccurred())

You can write:

Expect(SomethingThatMightFail()).Should(Succeed())

It is a mistake to use Succeed with a function that has multiple return values. Gomega's Ω and Expect functions automatically trigger failure if any return values after the first return value are non-zero/non-nil. This means that Ω(MultiReturnFunc()).ShouldNot(Succeed()) can never pass.

func WithTransform ¶

func WithTransform(transform interface{}, matcher types.GomegaMatcher) types.GomegaMatcher

WithTransform applies the `transform` to the actual value and matches it against `matcher`. The given transform must be either a function of one parameter that returns one value or a function of one parameter that returns two values, where the second value must be of the error type.

var plus1 = func(i int) int { return i + 1 }
Expect(1).To(WithTransform(plus1, Equal(2))

 var failingplus1 = func(i int) (int, error) { return 42, "this does not compute" }
 Expect(1).To(WithTransform(failingplus1, Equal(2)))

And(), Or(), Not() and WithTransform() allow matchers to be composed into complex expressions.