refactor(test): improve failure messages in custom matchers (#422)

display a readable diff of the "processed actual" vs "expected" values Fixes #421 Signed-off-by: Xavier Coulon <[email protected]>
bytesparadise · Sep 30, 2019 · 37e48f8 · 37e48f8
1 parent 6c57b55
commit 37e48f8
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Showing 19 changed files with 164 additions and 112 deletions.
diff --git a/testsupport/comparison.go b/testsupport/comparison.go
@@ -0,0 +1,32 @@
+package testsupport
+
+import (
+	"reflect"
+
+	"github.com/davecgh/go-spew/spew"
+	. "github.com/onsi/ginkgo" // nolint: go-lint
+	"github.com/sergi/go-diff/diffmatchpatch"
+)
+
+type comparison struct {
+	actual   string
+	expected string
+	diffs    string
+}
+
+// compare compares the 'actual' vs 'expected' values and produces a 'comparison' report
+func compare(actual interface{}, expected interface{}) comparison {
+	c := comparison{
+		actual:   spew.Sdump(actual),
+		expected: spew.Sdump(expected),
+	}
+	if !reflect.DeepEqual(actual, expected) {
+		dmp := diffmatchpatch.New()
+		diffs := dmp.DiffMain(c.actual, c.expected, true)
+		c.diffs = dmp.DiffPrettyText(diffs)
+	}
+	GinkgoT().Logf("actual:\n%s", c.actual)
+	GinkgoT().Logf("expected:\n%s", c.expected)
+	GinkgoT().Logf("diff:\n%s", c.diffs)
+	return c
+}
diff --git a/testsupport/comparison_test.go b/testsupport/comparison_test.go
@@ -0,0 +1,20 @@
+package testsupport_test
+
+import (
+	"reflect"
+
+	"github.com/davecgh/go-spew/spew"
+	"github.com/sergi/go-diff/diffmatchpatch"
+)
+
+// compare compares the 'actual' vs 'expected' values and produces a 'comparison' report
+func compare(actual interface{}, expected interface{}) string {
+	a := spew.Sdump(actual)
+	e := spew.Sdump(expected)
+	if reflect.DeepEqual(actual, expected) {
+		return ""
+	}
+	dmp := diffmatchpatch.New()
+	diffs := dmp.DiffMain(a, e, true)
+	return dmp.DiffPrettyText(diffs)
+}
diff --git a/testsupport/console_matcher.go b/testsupport/console_matcher.go
@@ -74,11 +74,11 @@ func (m *containMessageMatcher) Match(actual interface{}) (success bool, err err
 	return false, nil
 }
 
-func (m *containMessageMatcher) FailureMessage(actual interface{}) (message string) {
+func (m *containMessageMatcher) FailureMessage(_ interface{}) (message string) {
 	return fmt.Sprintf("expected console to contain message '%s' with level '%v'", m.msg, m.level)
 }
 
-func (m *containMessageMatcher) NegatedFailureMessage(actual interface{}) (message string) {
+func (m *containMessageMatcher) NegatedFailureMessage(_ interface{}) (message string) {
 	return fmt.Sprintf("expected console not to contain message '%s' with level '%v'", m.msg, m.level)
 }
 
@@ -121,10 +121,10 @@ func (m *containAnyMessageMatcher) Match(actual interface{}) (success bool, err
 	return false, nil
 }
 
-func (m *containAnyMessageMatcher) FailureMessage(actual interface{}) (message string) {
+func (m *containAnyMessageMatcher) FailureMessage(_ interface{}) (message string) {
 	return fmt.Sprintf("expected console to contain a message at level '%v'", m.levels)
 }
 
-func (m *containAnyMessageMatcher) NegatedFailureMessage(actual interface{}) (message string) {
+func (m *containAnyMessageMatcher) NegatedFailureMessage(_ interface{}) (message string) {
 	return fmt.Sprintf("expected console not to contain a message at level '%v'", m.levels)
 }
diff --git a/testsupport/document_block_matcher.go b/testsupport/document_block_matcher.go
@@ -2,16 +2,12 @@ package testsupport
 
 import (
 	"fmt"
-	"reflect"
 	"strings"
 
 	"github.com/bytesparadise/libasciidoc/pkg/parser"
-	"github.com/davecgh/go-spew/spew"
 
-	. "github.com/onsi/ginkgo"
 	"github.com/onsi/gomega/types"
 	"github.com/pkg/errors"
-	log "github.com/sirupsen/logrus"
 )
 
 // EqualDocumentBlock a custom matcher to verify that a document block matches the expectation
@@ -22,8 +18,9 @@ func EqualDocumentBlock(expected interface{}) types.GomegaMatcher {
 }
 
 type documentBlockMatcher struct {
-	expected interface{}
-	actual   interface{}
+	expected   interface{}
+	actual     interface{}
+	comparison comparison
 }
 
 func (m *documentBlockMatcher) Match(actual interface{}) (success bool, err error) {
@@ -40,17 +37,14 @@ func (m *documentBlockMatcher) Match(actual interface{}) (success bool, err erro
 	if err != nil {
 		return false, err
 	}
-	if log.IsLevelEnabled(log.DebugLevel) {
-		GinkgoT().Logf("actual:\n%v", spew.Sdump(m.actual))
-		GinkgoT().Logf("expected:\n%v", spew.Sdump(m.expected))
-	}
-	return reflect.DeepEqual(m.expected, m.actual), nil
+	m.comparison = compare(m.actual, m.expected)
+	return m.comparison.diffs == "", nil
 }
 
-func (m *documentBlockMatcher) FailureMessage(actual interface{}) (message string) {
-	return fmt.Sprintf("expected document blocks to match:\n\texpected: '%v'\n\tactual:   '%v'", m.expected, m.actual)
+func (m *documentBlockMatcher) FailureMessage(_ interface{}) (message string) {
+	return fmt.Sprintf("expected document blocks to match:\n%s", m.comparison.diffs)
 }
 
-func (m *documentBlockMatcher) NegatedFailureMessage(actual interface{}) (message string) {
-	return fmt.Sprintf("expected document blocks not to match:\n\texpected: '%v'\n\tactual:   '%v'", m.expected, m.actual)
+func (m *documentBlockMatcher) NegatedFailureMessage(_ interface{}) (message string) {
+	return fmt.Sprintf("expected document blocks not to match:\n%s", m.comparison.diffs)
 }
diff --git a/testsupport/document_block_matcher_test.go b/testsupport/document_block_matcher_test.go
@@ -54,8 +54,8 @@ var _ = Describe("document block assertions", func() {
 				},
 			},
 		}
-		Expect(matcher.FailureMessage(actual)).To(Equal(fmt.Sprintf("expected document blocks to match:\n\texpected: '%v'\n\tactual:   '%v'", expected, obtained)))
-		Expect(matcher.NegatedFailureMessage(actual)).To(Equal(fmt.Sprintf("expected document blocks not to match:\n\texpected: '%v'\n\tactual:   '%v'", expected, obtained)))
+		Expect(matcher.FailureMessage(actual)).To(Equal(fmt.Sprintf("expected document blocks to match:\n%s", compare(obtained, expected))))
+		Expect(matcher.NegatedFailureMessage(actual)).To(Equal(fmt.Sprintf("expected document blocks not to match:\n%s", compare(obtained, expected))))
 	})
 
 	It("should return error when invalid type is input", func() {

diff --git a/testsupport/document_matcher.go b/testsupport/document_matcher.go
@@ -2,7 +2,6 @@ package testsupport
 
 import (
 	"fmt"
-	"reflect"
 	"strings"
 
 	"github.com/bytesparadise/libasciidoc/pkg/parser"
@@ -20,8 +19,9 @@ func EqualDocument(expected types.Document) gomegatypes.GomegaMatcher {
 }
 
 type documentMatcher struct {
-	expected types.Document
-	actual   types.Document
+	expected   types.Document
+	actual     types.Document
+	comparison comparison
 }
 
 func (m *documentMatcher) Match(actual interface{}) (success bool, err error) {
@@ -34,13 +34,14 @@ func (m *documentMatcher) Match(actual interface{}) (success bool, err error) {
 	if err != nil {
 		return false, err
 	}
-	return reflect.DeepEqual(m.expected, m.actual), nil
+	m.comparison = compare(m.actual, m.expected)
+	return m.comparison.diffs == "", nil
 }
 
-func (m *documentMatcher) FailureMessage(actual interface{}) (message string) {
-	return fmt.Sprintf("expected documents to match:\n\texpected: '%v'\n\tactual:   '%v'", m.expected, m.actual)
+func (m *documentMatcher) FailureMessage(_ interface{}) (message string) {
+	return fmt.Sprintf("expected documents to match:\n%s", m.comparison.diffs)
 }
 
-func (m *documentMatcher) NegatedFailureMessage(actual interface{}) (message string) {
-	return fmt.Sprintf("expected documents not to match:\n\texpected: '%v'\n\tactual:   '%v'", m.expected, m.actual)
+func (m *documentMatcher) NegatedFailureMessage(_ interface{}) (message string) {
+	return fmt.Sprintf("expected documents not to match:\n%s", m.comparison.diffs)
 }
diff --git a/testsupport/document_matcher_test.go b/testsupport/document_matcher_test.go
@@ -70,8 +70,8 @@ var _ = Describe("document assertions", func() {
 				},
 			},
 		}
-		Expect(matcher.FailureMessage(actual)).To(Equal(fmt.Sprintf("expected documents to match:\n\texpected: '%v'\n\tactual:   '%v'", expected, obtained)))
-		Expect(matcher.NegatedFailureMessage(actual)).To(Equal(fmt.Sprintf("expected documents not to match:\n\texpected: '%v'\n\tactual:   '%v'", expected, obtained)))
+		Expect(matcher.FailureMessage(actual)).To(Equal(fmt.Sprintf("expected documents to match:\n%s", compare(obtained, expected))))
+		Expect(matcher.NegatedFailureMessage(actual)).To(Equal(fmt.Sprintf("expected documents not to match:\n%s", compare(obtained, expected))))
 	})
 
 	It("should return error when invalid type is input", func() {

diff --git a/testsupport/document_metadata_matcher.go b/testsupport/document_metadata_matcher.go
@@ -3,7 +3,6 @@ package testsupport
 import (
 	"context"
 	"fmt"
-	"reflect"
 
 	"github.com/bytesparadise/libasciidoc/pkg/renderer"
 	"github.com/bytesparadise/libasciidoc/pkg/types"
@@ -20,8 +19,9 @@ func HaveMetadata(expected interface{}) gomegatypes.GomegaMatcher {
 }
 
 type metadataMatcher struct {
-	expected interface{}
-	actual   types.DocumentAttributes
+	expected   interface{}
+	actual     interface{}
+	comparison comparison
 }
 
 func (m *metadataMatcher) Match(actual interface{}) (success bool, err error) {
@@ -32,13 +32,14 @@ func (m *metadataMatcher) Match(actual interface{}) (success bool, err error) {
 	ctx := renderer.Wrap(context.Background(), source)
 	renderer.ProcessDocumentHeader(ctx)
 	m.actual = ctx.Document.Attributes
-	return reflect.DeepEqual(m.expected, m.actual), nil
+	m.comparison = compare(m.actual, m.expected)
+	return m.comparison.diffs == "", nil
 }
 
-func (m *metadataMatcher) FailureMessage(actual interface{}) (message string) {
-	return fmt.Sprintf("expected document metadata to match:\n\texpected: '%v'\n\tactual:   '%v'", m.expected, m.actual)
+func (m *metadataMatcher) FailureMessage(_ interface{}) (message string) {
+	return fmt.Sprintf("expected document metadata to match:\n%s", m.comparison.diffs)
 }
 
-func (m *metadataMatcher) NegatedFailureMessage(actual interface{}) (message string) {
-	return fmt.Sprintf("expected document metadata not to match:\n\texpected: '%v'\n\tactual:   '%v'", m.expected, m.actual)
+func (m *metadataMatcher) NegatedFailureMessage(_ interface{}) (message string) {
+	return fmt.Sprintf("expected document metadata not to match:\n%s", m.comparison.diffs)
 }
diff --git a/testsupport/document_metadata_matcher_test.go b/testsupport/document_metadata_matcher_test.go
@@ -1,8 +1,10 @@
 package testsupport_test
 
 import (
+	"context"
 	"fmt"
 
+	"github.com/bytesparadise/libasciidoc/pkg/renderer"
 	"github.com/bytesparadise/libasciidoc/pkg/types"
 	"github.com/bytesparadise/libasciidoc/testsupport"
 
@@ -52,9 +54,11 @@ var _ = Describe("document metadata assertions", func() {
 		Expect(err).ToNot(HaveOccurred())
 		Expect(result).To(BeFalse())
 		// also verify the messages
-		obtained := types.DocumentAttributes{}
-		Expect(matcher.FailureMessage(actual)).To(Equal(fmt.Sprintf("expected document metadata to match:\n\texpected: '%v'\n\tactual:   '%v'", expected, obtained)))
-		Expect(matcher.NegatedFailureMessage(actual)).To(Equal(fmt.Sprintf("expected document metadata not to match:\n\texpected: '%v'\n\tactual:   '%v'", expected, obtained)))
+		ctx := renderer.Wrap(context.Background(), actual)
+		renderer.ProcessDocumentHeader(ctx)
+		obtained := ctx.Document.Attributes
+		Expect(matcher.FailureMessage(actual)).To(Equal(fmt.Sprintf("expected document metadata to match:\n%s", compare(obtained, expected))))
+		Expect(matcher.NegatedFailureMessage(actual)).To(Equal(fmt.Sprintf("expected document metadata not to match:\n%s", compare(obtained, expected))))
 	})
 
 	It("should return error when invalid type is input", func() {

diff --git a/testsupport/document_preamble_matcher.go b/testsupport/document_preamble_matcher.go
@@ -3,7 +3,6 @@ package testsupport
 import (
 	"context"
 	"fmt"
-	"reflect"
 
 	"github.com/bytesparadise/libasciidoc/pkg/renderer"
 	"github.com/bytesparadise/libasciidoc/pkg/types"
@@ -20,8 +19,9 @@ func HavePreamble(expected types.Document) gomegatypes.GomegaMatcher {
 }
 
 type preambleMatcher struct {
-	expected types.Document
-	actual   types.Document
+	expected   types.Document
+	actual     types.Document
+	comparison comparison
 }
 
 func (m *preambleMatcher) Match(actual interface{}) (success bool, err error) {
@@ -32,13 +32,14 @@ func (m *preambleMatcher) Match(actual interface{}) (success bool, err error) {
 	ctx := renderer.Wrap(context.Background(), doc)
 	renderer.IncludePreamble(ctx)
 	m.actual = ctx.Document
-	return reflect.DeepEqual(m.expected, m.actual), nil
+	m.comparison = compare(m.actual, m.expected)
+	return m.comparison.diffs == "", nil
 }
 
-func (m *preambleMatcher) FailureMessage(actual interface{}) (message string) {
-	return fmt.Sprintf("expected document to match:\n\texpected: '%v'\n\tactual:   '%v'", m.expected, m.actual)
+func (m *preambleMatcher) FailureMessage(_ interface{}) (message string) {
+	return fmt.Sprintf("expected documents to match:\n%s", m.comparison.diffs)
 }
 
-func (m *preambleMatcher) NegatedFailureMessage(actual interface{}) (message string) {
-	return fmt.Sprintf("expected document not to match:\n\texpected: '%v'\n\tactual:   '%v'", m.expected, m.actual)
+func (m *preambleMatcher) NegatedFailureMessage(_ interface{}) (message string) {
+	return fmt.Sprintf("expected documents not to match:\n%s", m.comparison.diffs)
 }
diff --git a/testsupport/document_preamble_matcher_test.go b/testsupport/document_preamble_matcher_test.go
@@ -1,8 +1,10 @@
 package testsupport_test
 
 import (
+	"context"
 	"fmt"
 
+	"github.com/bytesparadise/libasciidoc/pkg/renderer"
 	"github.com/bytesparadise/libasciidoc/pkg/types"
 	"github.com/bytesparadise/libasciidoc/testsupport"
 
@@ -103,15 +105,13 @@ var _ = Describe("document preamble assertions", func() {
 		Expect(err).ToNot(HaveOccurred())
 		Expect(result).To(BeFalse())
 		// also verify messages
-		obtained := types.Document{
-			Attributes:         types.DocumentAttributes{},
-			ElementReferences:  types.ElementReferences{},
-			Footnotes:          types.Footnotes{},
-			FootnoteReferences: types.FootnoteReferences{},
-			Elements:           []interface{}{},
-		}
-		Expect(matcher.FailureMessage(actual)).To(Equal(fmt.Sprintf("expected document to match:\n\texpected: '%v'\n\tactual:   '%v'", expected, obtained)))
-		Expect(matcher.NegatedFailureMessage(actual)).To(Equal(fmt.Sprintf("expected document not to match:\n\texpected: '%v'\n\tactual:   '%v'", expected, obtained)))
+		ctx := renderer.Wrap(context.Background(), actual)
+		renderer.IncludePreamble(ctx)
+		obtained := ctx.Document
+		GinkgoT().Logf(matcher.FailureMessage(actual))
+		GinkgoT().Logf(fmt.Sprintf("expected documents to match:\n%s", compare(obtained, expected)))
+		Expect(matcher.FailureMessage(actual)).To(Equal(fmt.Sprintf("expected documents to match:\n%s", compare(obtained, expected))))
+		Expect(matcher.NegatedFailureMessage(actual)).To(Equal(fmt.Sprintf("expected documents not to match:\n%s", compare(obtained, expected))))
 	})
 
 	It("should return error when invalid type is input", func() {

diff --git a/testsupport/document_toc_matcher.go b/testsupport/document_toc_matcher.go
@@ -3,7 +3,6 @@ package testsupport
 import (
 	"context"
 	"fmt"
-	"reflect"
 
 	"github.com/bytesparadise/libasciidoc/pkg/renderer"
 	"github.com/bytesparadise/libasciidoc/pkg/types"
@@ -20,8 +19,9 @@ func HaveTableOfContents(expected types.Document) gomegatypes.GomegaMatcher {
 }
 
 type tocMatcher struct {
-	expected types.Document
-	actual   types.Document
+	expected   types.Document
+	actual     types.Document
+	comparison comparison
 }
 
 func (m *tocMatcher) Match(actual interface{}) (success bool, err error) {
@@ -32,13 +32,14 @@ func (m *tocMatcher) Match(actual interface{}) (success bool, err error) {
 	ctx := renderer.Wrap(context.Background(), doc)
 	renderer.IncludeTableOfContents(ctx)
 	m.actual = ctx.Document
-	return reflect.DeepEqual(m.expected, m.actual), nil
+	m.comparison = compare(m.actual, m.expected)
+	return m.comparison.diffs == "", nil
 }
 
-func (m *tocMatcher) FailureMessage(actual interface{}) (message string) {
-	return fmt.Sprintf("expected document to match:\n\texpected: '%v'\n\tactual:   '%v'", m.expected, m.actual)
+func (m *tocMatcher) FailureMessage(_ interface{}) (message string) {
+	return fmt.Sprintf("expected documents to match:\n%s", m.comparison.diffs)
 }
 
-func (m *tocMatcher) NegatedFailureMessage(actual interface{}) (message string) {
-	return fmt.Sprintf("expected document not to match:\n\texpected: '%v'\n\tactual:   '%v'", m.expected, m.actual)
+func (m *tocMatcher) NegatedFailureMessage(_ interface{}) (message string) {
+	return fmt.Sprintf("expected documents not to match:\n%s", m.comparison.diffs)
 }
diff --git a/testsupport/document_toc_matcher_test.go b/testsupport/document_toc_matcher_test.go
@@ -82,8 +82,8 @@ var _ = Describe("document table of contents assertions", func() {
 		// then
 		Expect(err).ToNot(HaveOccurred())
 		Expect(result).To(BeFalse())
-		Expect(matcher.FailureMessage(actual)).To(Equal(fmt.Sprintf("expected document to match:\n\texpected: '%v'\n\tactual:   '%v'", expected, types.Document{})))
-		Expect(matcher.NegatedFailureMessage(actual)).To(Equal(fmt.Sprintf("expected document not to match:\n\texpected: '%v'\n\tactual:   '%v'", expected, types.Document{})))
+		Expect(matcher.FailureMessage(actual)).To(Equal(fmt.Sprintf("expected documents to match:\n%s", compare(types.Document{}, expected))))
+		Expect(matcher.NegatedFailureMessage(actual)).To(Equal(fmt.Sprintf("expected documents not to match:\n%s", compare(types.Document{}, expected))))
 	})
 
 	It("should return error when invalid type is input", func() {