Provide a useful implementation of something compatible with testing.T (#571)

* Attempting to provide a useful implementation of something compatible with testing.T

* Handle Fail calls on the TestingT in the right place

* Provide as much of testing.T as possible + tidy up

* Add initial tests for testingT support

* Check compatibility with testing.T and friends

Co-authored-by: Piotr Bocheński <[email protected]>

* Update assert-godogs example to show new usage. Rename 'GetTestingT(ctx)' to 'T(ctx)'

* Update changelog and readme with new usage

* Improve test coverage

* Review updates

---------

Co-authored-by: Piotr Bocheński <[email protected]>

Author: mrsheepuk

CHANGELOG.md

@@ -8,6 +8,9 @@ This document is formatted according to the principles of [Keep A CHANGELOG](htt
 
 ## Unreleased
 
+### Added
+- Provide testing.T-compatible interface on test context, allowing usage of assertion libraries such as testify's assert/require - ([571](https://github.com/cucumber/godog/pull/571) - [mrsheepuk](https://github.com/mrsheepuk))
+
 ## [v0.14.0]
 ### Added
 - Improve ErrSkip handling, add test for Summary and operations order ([584](https://github.com/cucumber/godog/pull/584) - [vearutop](https://github.com/vearutop))

README.md

@@ -495,31 +495,12 @@ If you want to filter scenarios by tags, you can use the `-t=<expression>` or `-
 A more extensive example can be [found here](/_examples/assert-godogs).
 
 ```go
-func thereShouldBeRemaining(remaining int) error {
-	return assertExpectedAndActual(
-		assert.Equal, Godogs, remaining,
-		"Expected %d godogs to be remaining, but there is %d", remaining, Godogs,
-	)
-}
-
-// assertExpectedAndActual is a helper function to allow the step function to call
-// assertion functions where you want to compare an expected and an actual value.
-func assertExpectedAndActual(a expectedAndActualAssertion, expected, actual interface{}, msgAndArgs ...interface{}) error {
-	var t asserter
-	a(&t, expected, actual, msgAndArgs...)
-	return t.err
-}
-
-type expectedAndActualAssertion func(t assert.TestingT, expected, actual interface{}, msgAndArgs ...interface{}) bool
-
-// asserter is used to be able to retrieve the error reported by the called assertion
-type asserter struct {
-	err error
-}
-
-// Errorf is used by the called assertion to report an error
-func (a *asserter) Errorf(format string, args ...interface{}) {
-	a.err = fmt.Errorf(format, args...)
+func thereShouldBeRemaining(ctx context.Context, remaining int) error {
+	assert.Equal(
+    godog.T(ctx), Godogs, remaining, 
+    "Expected %d godogs to be remaining, but there is %d", remaining, Godogs,
+  )
+	return nil
 }
 ```
 

_examples/assert-godogs/godogs_test.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"context"
-	"fmt"
 	"os"
 	"testing"
 
@@ -36,31 +35,22 @@ func thereAreGodogs(available int) error {
 	return nil
 }
 
-func iEat(num int) error {
-	err := assertExpectedAndActual(
-		assert.GreaterOrEqual, Godogs, num,
-		"You cannot eat %d godogs, there are %d available", num, Godogs,
-	)
-	if err != nil {
-		return err
+func iEat(ctx context.Context, num int) error {
+	if !assert.GreaterOrEqual(godog.T(ctx), Godogs, num, "You cannot eat %d godogs, there are %d available", num, Godogs) {
+		return nil
 	}
-
 	Godogs -= num
 	return nil
 }
 
-func thereShouldBeRemaining(remaining int) error {
-	return assertExpectedAndActual(
-		assert.Equal, Godogs, remaining,
-		"Expected %d godogs to be remaining, but there is %d", remaining, Godogs,
-	)
+func thereShouldBeRemaining(ctx context.Context, remaining int) error {
+	assert.Equal(godog.T(ctx), Godogs, remaining, "Expected %d godogs to be remaining, but there is %d", remaining, Godogs)
+	return nil
 }
 
-func thereShouldBeNoneRemaining() error {
-	return assertActual(
-		assert.Empty, Godogs,
-		"Expected none godogs to be remaining, but there is %d", Godogs,
-	)
+func thereShouldBeNoneRemaining(ctx context.Context) error {
+	assert.Empty(godog.T(ctx), Godogs, "Expected none godogs to be remaining, but there is %d", Godogs)
+	return nil
 }
 
 func InitializeScenario(ctx *godog.ScenarioContext) {
@@ -74,34 +64,3 @@ func InitializeScenario(ctx *godog.ScenarioContext) {
 	ctx.Step(`^there should be (\d+) remaining$`, thereShouldBeRemaining)
 	ctx.Step(`^there should be none remaining$`, thereShouldBeNoneRemaining)
 }
-
-// assertExpectedAndActual is a helper function to allow the step function to call
-// assertion functions where you want to compare an expected and an actual value.
-func assertExpectedAndActual(a expectedAndActualAssertion, expected, actual interface{}, msgAndArgs ...interface{}) error {
-	var t asserter
-	a(&t, expected, actual, msgAndArgs...)
-	return t.err
-}
-
-type expectedAndActualAssertion func(t assert.TestingT, expected, actual interface{}, msgAndArgs ...interface{}) bool
-
-// assertActual is a helper function to allow the step function to call
-// assertion functions where you want to compare an actual value to a
-// predined state like nil, empty or true/false.
-func assertActual(a actualAssertion, actual interface{}, msgAndArgs ...interface{}) error {
-	var t asserter
-	a(&t, actual, msgAndArgs...)
-	return t.err
-}
-
-type actualAssertion func(t assert.TestingT, actual interface{}, msgAndArgs ...interface{}) bool
-
-// asserter is used to be able to retrieve the error reported by the called assertion
-type asserter struct {
-	err error
-}
-
-// Errorf is used by the called assertion to report an error
-func (a *asserter) Errorf(format string, args ...interface{}) {
-	a.err = fmt.Errorf(format, args...)
-}

features/formatter/events.feature

@@ -13,7 +13,7 @@ Feature: event stream formatter
       """
 
   Scenario: should process simple scenario
-    Given a feature path "features/load.feature:26"
+    Given a feature path "features/load.feature:27"
     When I run feature suite with formatter "events"
     Then the following events should be fired:
       """
@@ -34,7 +34,7 @@ Feature: event stream formatter
       """
 
   Scenario: should process outline scenario
-    Given a feature path "features/load.feature:34"
+    Given a feature path "features/load.feature:35"
     When I run feature suite with formatter "events"
     Then the following events should be fired:
       """

features/formatter/pretty.feature

@@ -350,7 +350,7 @@ Feature: pretty formatter
   Scenario: Should scenarios identified with path:line and preserve the order.
     Given a feature path "features/load.feature:6"
     And a feature path "features/multistep.feature:6"
-    And a feature path "features/load.feature:26"
+    And a feature path "features/load.feature:27"
     And a feature path "features/multistep.feature:23"
     When I run feature suite with formatter "pretty"
     Then the rendered output will be as follows:
@@ -363,7 +363,7 @@ Feature: pretty formatter
       Scenario: load features within path    # features/load.feature:6
         Given a feature path "features"      # suite_context_test.go:0 -> *godogFeaturesScenario
         When I parse features                # suite_context_test.go:0 -> *godogFeaturesScenario
-        Then I should have 13 feature files: # suite_context_test.go:0 -> *godogFeaturesScenario
+        Then I should have 14 feature files: # suite_context_test.go:0 -> *godogFeaturesScenario
           \"\"\"
           features/background.feature
           features/events.feature
@@ -378,6 +378,7 @@ Feature: pretty formatter
           features/run.feature
           features/snippets.feature
           features/tags.feature
+          features/testingt.feature
           \"\"\"
 
     Feature: run features with nested steps
@@ -407,7 +408,7 @@ Feature: pretty formatter
       As a test suite
       I need to be able to load features
 
-      Scenario: load a specific feature file         # features/load.feature:26
+      Scenario: load a specific feature file         # features/load.feature:27
         Given a feature path "features/load.feature" # suite_context_test.go:0 -> *godogFeaturesScenario
         When I parse features                        # suite_context_test.go:0 -> *godogFeaturesScenario
         Then I should have 1 feature file:           # suite_context_test.go:0 -> *godogFeaturesScenario

features/lang.feature

@@ -8,7 +8,7 @@ Savybė: užkrauti savybes
   Scenarijus: savybių užkrovimas iš aplanko
     Duota savybių aplankas "features"
     Kai aš išskaitau savybes
-    Tada aš turėčiau turėti 13 savybių failus:
+    Tada aš turėčiau turėti 14 savybių failus:
       """
       features/background.feature
       features/events.feature
@@ -23,4 +23,5 @@ Savybė: užkrauti savybes
       features/run.feature
       features/snippets.feature
       features/tags.feature
+      features/testingt.feature
       """

features/load.feature

@@ -6,7 +6,7 @@ Feature: load features
   Scenario: load features within path
     Given a feature path "features"
     When I parse features
-    Then I should have 13 feature files:
+    Then I should have 14 feature files:
       """
       features/background.feature
       features/events.feature
@@ -21,6 +21,7 @@ Feature: load features
       features/run.feature
       features/snippets.feature
       features/tags.feature
+      features/testingt.feature
       """
 
   Scenario: load a specific feature file