feat: improve consumer error reporting

MIGRATION.md

@@ -31,7 +31,7 @@ The following package exposes aliases for the most commonly used interfaces for
 #### Primary Interface
 
 - `dsl.Pact` was the primary interface. This is now replaced with `NewPactV2` and the `NewPactV3` methods, which will return you a builder for the corresponding specification.
-- `Verify` is now `ExecuteTest` to avoid ambiguity with provider side verification.
+- `Verify` is now `ExecuteTest` to avoid ambiguity with provider side verification. It also accepts a `*testing.T` argument, to improve error reporting and resolution.
 
 These are available in consumer package: `"github.com/pact-foundation/pact-go/v2/consumer"`
 

consumer/http.go

@@ -15,7 +15,12 @@ import (
 	"log"
 	"os"
 	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
 	"time"
+	"unicode"
+	"unicode/utf8"
 
 	native "github.com/pact-foundation/pact-go/v2/internal/native/mockserver"
 	logging "github.com/pact-foundation/pact-go/v2/log"
@@ -125,7 +130,7 @@ func (p *httpMockProvider) configure() error {
 // ExecuteTest runs the current test case against a Mock Service.
 // Will cleanup interactions between tests within a suite
 // and write the pact file if successful
-func (p *httpMockProvider) ExecuteTest(integrationTest func(MockServerConfig) error) error {
+func (p *httpMockProvider) ExecuteTest(t *testing.T, integrationTest func(MockServerConfig) error) error {
 	log.Println("[DEBUG] pact verify")
 
 	var err error
@@ -153,7 +158,7 @@ func (p *httpMockProvider) ExecuteTest(integrationTest func(MockServerConfig) er
 	})
 
 	res, mismatches := p.mockserver.Verify(p.config.Port, p.config.PactDir)
-	p.displayMismatches(mismatches)
+	p.displayMismatches(t, mismatches)
 
 	if err != nil {
 		return err
@@ -177,33 +182,121 @@ func (p *httpMockProvider) reset() {
 	p.configure()
 }
 
-// TODO: pretty print this to make it really easy to understand the problems
+// TODO: improve / pretty print this to make it really easy to understand the problems
 // See existing Pact/Ruby code examples
-func (p *httpMockProvider) displayMismatches(mismatches []native.MismatchedRequest) {
+func (p *httpMockProvider) displayMismatches(t *testing.T, mismatches []native.MismatchedRequest) {
 	if len(mismatches) > 0 {
+
+		if len(callerInfo()) > 0 {
+			fmt.Printf("\n\n%s:\n", callerInfo()[len(callerInfo())-1])
+		}
+		fmt.Println("\tPact Verification Failed for:", t.Name())
+		fmt.Println()
+		fmt.Println("\t\tDiff:")
 		log.Println("[INFO] pact validation failed, errors: ")
 		for _, m := range mismatches {
 			formattedRequest := fmt.Sprintf("%s %s", m.Request.Method, m.Request.Path)
 			switch m.Type {
 			case "missing-request":
-				fmt.Printf("Expected request to: %s, but did not receive one\n", formattedRequest)
+				fmt.Printf("\t\texpected: \t%s (Expected request that was not received)\n", formattedRequest)
 			case "request-not-found":
-				fmt.Printf("Unexpected request was received: %s\n", formattedRequest)
+				fmt.Printf("\t\tactual: \t%s (Unexpected request was received)\n", formattedRequest)
 			default:
 				// TODO:
 			}
 
 			for _, detail := range m.Mismatches {
 				switch detail.Type {
 				case "HeaderMismatch":
-					fmt.Printf("Comparing Header: '%s'\n", detail.Key)
-					fmt.Println(detail.Mismatch)
-					fmt.Println("Expected:", detail.Expected)
-					fmt.Println("Actual:", detail.Actual)
+					fmt.Printf("\t\t\tComparing Header: '%s'\n", detail.Key)
+					fmt.Println("\t\t\t", detail.Mismatch)
+					fmt.Println("\t\t\texpected: \t", detail.Expected)
+					fmt.Println("\t\t\tactual: \t", detail.Actual)
+				case "BodyMismatch":
+					fmt.Printf("\t\t\t%s\n", detail.Mismatch)
+					fmt.Println("\t\t\texpected:\t", detail.Expected)
+					fmt.Println("\t\t\tactual:\t\t", detail.Actual)
 				}
 			}
 		}
+		fmt.Println()
+		fmt.Println()
+	}
+}
+
+// Stolen from "github.com/stretchr/testify/assert"
+func callerInfo() []string {
+
+	var pc uintptr
+	var ok bool
+	var file string
+	var line int
+	var name string
+
+	callers := []string{}
+	for i := 0; ; i++ {
+		pc, file, line, ok = runtime.Caller(i)
+		if !ok {
+			// The breaks below failed to terminate the loop, and we ran off the
+			// end of the call stack.
+			break
+		}
+
+		// This is a huge edge case, but it will panic if this is the case, see #180
+		if file == "<autogenerated>" {
+			break
+		}
+
+		f := runtime.FuncForPC(pc)
+		if f == nil {
+			break
+		}
+		name = f.Name()
+
+		// testing.tRunner is the standard library function that calls
+		// tests. Subtests are called directly by tRunner, without going through
+		// the Test/Benchmark/Example function that contains the t.Run calls, so
+		// with subtests we should break when we hit tRunner, without adding it
+		// to the list of callers.
+		if name == "testing.tRunner" {
+			break
+		}
+
+		parts := strings.Split(file, "/")
+		file = parts[len(parts)-1]
+		if len(parts) > 1 {
+			dir := parts[len(parts)-2]
+			if (dir != "assert" && dir != "mock" && dir != "require") || file == "mock_test.go" {
+				callers = append(callers, fmt.Sprintf("%s:%d", file, line))
+			}
+		}
+
+		// Drop the package
+		segments := strings.Split(name, ".")
+		name = segments[len(segments)-1]
+		if isTest(name, "Test") ||
+			isTest(name, "Benchmark") ||
+			isTest(name, "Example") {
+			break
+		}
+	}
+
+	return callers
+}
+
+// Stolen from the `go test` tool.
+// isTest tells whether name looks like a test (or benchmark, according to prefix).
+// It is a Test (say) if there is a character after Test that is not a lower-case letter.
+// We don't want TesticularCancer.
+func isTest(name, prefix string) bool {
+	if !strings.HasPrefix(name, prefix) {
+		return false
+	}
+	if len(name) == len(prefix) { // "Test" is ok
+		return true
 	}
+	r, _ := utf8.DecodeRuneInString(name[len(prefix):])
+	return !unicode.IsLower(r)
 }
 
 // writePact may be called after each interaction with a mock server is completed

docs/consumer.md

@@ -56,7 +56,7 @@ func TestProductAPIClient(t *testing.T) {
 		WithBodyMatch(&Product{}) // This uses struct tags for matchers
 
 	// Act: test our API client behaves correctly
-	err = mockProvider.ExecuteTest(func(config MockServerConfig) error {
+	err = mockProvider.ExecuteTest(t, func(config MockServerConfig) error {
 		// Initialise the API client and point it at the Pact mock server
 		// Pact spins up a dedicated mock server for each test
 		client := newClient(config.Host, config.Port)

examples/basic_test.go

@@ -29,7 +29,7 @@ func TestProductAPIClient(t *testing.T) {
 		WithBodyMatch(&Product{})
 
 	// Act: test our API client behaves correctly
-	err = mockProvider.ExecuteTest(func(config MockServerConfig) error {
+	err = mockProvider.ExecuteTest(t, func(config MockServerConfig) error {
 		// Initialise the API client and point it at the Pact mock server
 		client := newClient(config.Host, config.Port)
 

examples/consumer_test.go

@@ -56,7 +56,7 @@ func TestConsumerV2(t *testing.T) {
 		})
 
 	// Execute pact test
-	err = mockProvider.ExecuteTest(test)
+	err = mockProvider.ExecuteTest(t, test)
 	assert.NoError(t, err)
 }
 
@@ -87,7 +87,7 @@ func TestConsumerV2_Match(t *testing.T) {
 		WithBodyMatch(&User{})
 
 	// Execute pact test
-	err = mockProvider.ExecuteTest(test)
+	err = mockProvider.ExecuteTest(t, test)
 	assert.NoError(t, err)
 }
 
@@ -144,7 +144,7 @@ func TestConsumerV3(t *testing.T) {
 		})
 
 	// Execute pact test
-	err = mockProvider.ExecuteTest(test)
+	err = mockProvider.ExecuteTest(t, test)
 	assert.NoError(t, err)
 }
 
@@ -193,7 +193,7 @@ func TestConsumerV2AllInOne(t *testing.T) {
 		})
 
 	// Execute pact test
-	err = mockProvider.ExecuteTest(legacyTest)
+	err = mockProvider.ExecuteTest(t, legacyTest)
 	assert.NoError(t, err)
 }