introduces Eventually.Within.ProbeEvery with tests and documentation (#591)

Author: thediveo

docs/index.md

@@ -252,10 +252,11 @@ The first optional argument is the timeout (which defaults to 1s), the second is
 
 > As with synchronous assertions, you can annotate asynchronous assertions by passing either a format string and optional inputs or a function of type `func() string` after the `GomegaMatcher`.
 
-Alternatively, the timeout and polling interval can also be specified by chaining `WithTimeout` and `WithPolling` to `Eventually`:
+Alternatively, the timeout and polling interval can also be specified by chaining `Within` and `ProbeEvery` or `WithTimeout` and `WithPolling` to `Eventually`:
 
 ```go
 Eventually(ACTUAL).WithTimeout(TIMEOUT).WithPolling(POLLING_INTERVAL).Should(MATCHER)
+Eventually(ACTUAL).Within(TIMEOUT).ProbeEvery(POLLING_INTERVAL).Should(MATCHER)
 ```
 
 Eventually works with any Gomega compatible matcher and supports making assertions against three categories of `ACTUAL` value:

internal/async_assertion.go

@@ -102,6 +102,16 @@ func (assertion *AsyncAssertion) WithPolling(interval time.Duration) types.Async
 	return assertion
 }
 
+func (assertion *AsyncAssertion) Within(timeout time.Duration) types.AsyncAssertion {
+	assertion.timeoutInterval = timeout
+	return assertion
+}
+
+func (assertion *AsyncAssertion) ProbeEvery(interval time.Duration) types.AsyncAssertion {
+	assertion.pollingInterval = interval
+	return assertion
+}
+
 func (assertion *AsyncAssertion) Should(matcher types.GomegaMatcher, optionalDescription ...interface{}) bool {
 	assertion.g.THelper()
 	vetOptionalDescription("Asynchronous assertion", optionalDescription...)

internal/async_assertion_test.go

@@ -59,6 +59,26 @@ var _ = Describe("Asynchronous Assertions", func() {
 				Ω(ig.FailureMessage).Should(ContainSubstring("positive: no match"))
 				Ω(ig.FailureSkip).Should(Equal([]int{3}))
 			})
+
+			It("maps Within() correctly to timeout and polling intervals", func() {
+				counter := 0
+				ig.G.Eventually(func() bool {
+					counter++
+					return false
+				}).WithTimeout(0).WithPolling(20 * time.Millisecond).Within(200 * time.Millisecond).Should(BeTrue())
+				Ω(counter).Should(BeNumerically(">", 2))
+				Ω(counter).Should(BeNumerically("<", 20))
+
+				counter = 0
+				ig.G.Eventually(func() bool {
+					counter++
+					return false
+				}).WithTimeout(0).WithPolling(0). // first zero intervals, then set them
+									Within(200 * time.Millisecond).ProbeEvery(20 * time.Millisecond).
+									Should(BeTrue())
+				Ω(counter).Should(BeNumerically(">", 2))
+				Ω(counter).Should(BeNumerically("<", 20))
+			})
 		})
 
 		Context("the negative case", func() {
@@ -309,7 +329,7 @@ var _ = Describe("Asynchronous Assertions", func() {
 			})
 		})
 
-		Context("when passed a function that takes no arguments and returns mutliple values", func() {
+		Context("when passed a function that takes no arguments and returns multiple values", func() {
 			Context("with Eventually", func() {
 				It("polls the function until the first returned value satisfies the matcher _and_ all additional values are zero", func() {
 					counter, s, f, err := 0, "hi", Foo{Bar: "hi"}, errors.New("hi")

types/types.go

@@ -6,7 +6,7 @@ import (
 
 type GomegaFailHandler func(message string, callerSkip ...int)
 
-//A simple *testing.T interface wrapper
+// A simple *testing.T interface wrapper
 type GomegaTestingT interface {
 	Helper()
 	Fatalf(format string, args ...interface{})
@@ -30,9 +30,9 @@ type Gomega interface {
 	SetDefaultConsistentlyPollingInterval(time.Duration)
 }
 
-//All Gomega matchers must implement the GomegaMatcher interface
+// All Gomega matchers must implement the GomegaMatcher interface
 //
-//For details on writing custom matchers, check out: http://onsi.github.io/gomega/#adding-your-own-matchers
+// For details on writing custom matchers, check out: http://onsi.github.io/gomega/#adding-your-own-matchers
 type GomegaMatcher interface {
 	Match(actual interface{}) (success bool, err error)
 	FailureMessage(actual interface{}) (message string)
@@ -70,6 +70,8 @@ type AsyncAssertion interface {
 	WithOffset(offset int) AsyncAssertion
 	WithTimeout(interval time.Duration) AsyncAssertion
 	WithPolling(interval time.Duration) AsyncAssertion
+	Within(timeout time.Duration) AsyncAssertion
+	ProbeEvery(interval time.Duration) AsyncAssertion
 }
 
 // Assertions are returned by Ω and Expect and enable assertions against Gomega matchers