Merge pull request #37 from JosephWoodward/scrubber-support

Initial support for scrubbers via a fluent API

Author: emilybache

approvals.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"os"
 	"reflect"
+	"regexp"
 	"strings"
 
 	"github.com/approvals/go-approval-tests/reporters"
@@ -32,13 +33,49 @@ type Failable interface {
 }
 
 // VerifyWithExtension Example:
-//   VerifyWithExtension(t, strings.NewReader("Hello"), ".txt")
-func VerifyWithExtension(t Failable, reader io.Reader, extWithDot string) {
+//   VerifyWithExtension(t, strings.NewReader("Hello"), ".json")
+// Deprecated: Please use Verify with the Options() fluent syntax.
+func VerifyWithExtension(t Failable, reader io.Reader, extWithDot string, opts ...verifyOptions) {
 	t.Helper()
+	Verify(t, reader, alwaysOption(opts).WithExtension(extWithDot))
+}
+
+// Verify Example:
+//   Verify(t, strings.NewReader("Hello"))
+func Verify(t Failable, reader io.Reader, opts ...verifyOptions) {
+	t.Helper()
+
+	if len(opts) > 1 {
+		panic("Please use fluent syntax for options, see documentation for more information")
+	}
+
+	var extWithDot string
+	if len(opts) == 0 || opts[0].extWithDot == "" {
+		extWithDot = ".txt"
+	} else {
+		extWithDot = opts[0].extWithDot
+	}
+
 	namer := getApprovalName(t)
 
+	if len(opts) > 0 {
+		b, err := io.ReadAll(reader)
+		if err != nil {
+			panic(err)
+		}
+
+		result := string(b)
+		for _, o := range opts {
+			for _, sb := range o.scrubbers {
+				result = sb(result)
+			}
+		}
+
+		reader = strings.NewReader(result)
+	}
+
 	reporter := getReporter()
-	var err = namer.compare(namer.getApprovalFile(extWithDot), namer.getReceivedFile(extWithDot), reader)
+	err := namer.compare(namer.getApprovalFile(extWithDot), namer.getReceivedFile(extWithDot), reader)
 	if err != nil {
 		reporter.Report(namer.getApprovalFile(extWithDot), namer.getReceivedFile(extWithDot))
 		t.Log("Failed Approval: received does not match approved.")
@@ -48,24 +85,17 @@ func VerifyWithExtension(t Failable, reader io.Reader, extWithDot string) {
 	}
 }
 
-// Verify Example:
-//   Verify(t, strings.NewReader("Hello"))
-func Verify(t Failable, reader io.Reader) {
-	t.Helper()
-	VerifyWithExtension(t, reader, ".txt")
-}
-
 // VerifyString stores the passed string into the received file and confirms
 // that it matches the approved local file. On failure, it will launch a reporter.
-func VerifyString(t Failable, s string) {
+func VerifyString(t Failable, s string, opts ...verifyOptions) {
 	t.Helper()
 	reader := strings.NewReader(s)
-	Verify(t, reader)
+	Verify(t, reader, opts...)
 }
 
 // VerifyXMLStruct Example:
 //   VerifyXMLStruct(t, xml)
-func VerifyXMLStruct(t Failable, obj interface{}) {
+func VerifyXMLStruct(t Failable, obj interface{}, opts ...verifyOptions) {
 	t.Helper()
 	xmlContent, err := xml.MarshalIndent(obj, "", "  ")
 	if err != nil {
@@ -74,15 +104,15 @@ func VerifyXMLStruct(t Failable, obj interface{}) {
 			tip = "when using anonymous types be sure to include\n  XMLName xml.Name `xml:\"Your_Name_Here\"`\n"
 		}
 		message := fmt.Sprintf("error while pretty printing XML\n%verror:\n  %v\nXML:\n  %v\n", tip, err, obj)
-		VerifyWithExtension(t, strings.NewReader(message), ".xml")
+		Verify(t, strings.NewReader(message), alwaysOption(opts).WithExtension(".xml"))
 	} else {
-		VerifyWithExtension(t, bytes.NewReader(xmlContent), ".xml")
+		Verify(t, bytes.NewReader(xmlContent), alwaysOption(opts).WithExtension(".xml"))
 	}
 }
 
 // VerifyXMLBytes Example:
 //   VerifyXMLBytes(t, []byte("<Test/>"))
-func VerifyXMLBytes(t Failable, bs []byte) {
+func VerifyXMLBytes(t Failable, bs []byte, opts ...verifyOptions) {
 	t.Helper()
 	type node struct {
 		Attr     []xml.Attr
@@ -95,65 +125,66 @@ func VerifyXMLBytes(t Failable, bs []byte) {
 	err := xml.Unmarshal(bs, &x)
 	if err != nil {
 		message := fmt.Sprintf("error while parsing XML\nerror:\n  %s\nXML:\n  %s\n", err, string(bs))
-		VerifyWithExtension(t, strings.NewReader(message), ".xml")
+		Verify(t, strings.NewReader(message), alwaysOption(opts).WithExtension(".xml"))
 	} else {
-		VerifyXMLStruct(t, x)
+		VerifyXMLStruct(t, x, opts...)
 	}
 }
 
 // VerifyJSONStruct Example:
 //   VerifyJSONStruct(t, json)
-func VerifyJSONStruct(t Failable, obj interface{}) {
+func VerifyJSONStruct(t Failable, obj interface{}, opts ...verifyOptions) {
 	t.Helper()
+
 	jsonb, err := json.MarshalIndent(obj, "", "  ")
 	if err != nil {
 		message := fmt.Sprintf("error while pretty printing JSON\nerror:\n  %s\nJSON:\n  %s\n", err, obj)
-		VerifyWithExtension(t, strings.NewReader(message), ".json")
+		Verify(t, strings.NewReader(message), alwaysOption(opts).WithExtension(".json"))
 	} else {
-		VerifyWithExtension(t, bytes.NewReader(jsonb), ".json")
+		Verify(t, bytes.NewReader(jsonb), alwaysOption(opts).WithExtension(".json"))
 	}
 }
 
 // VerifyJSONBytes Example:
 //   VerifyJSONBytes(t, []byte("{ \"Greeting\": \"Hello\" }"))
-func VerifyJSONBytes(t Failable, bs []byte) {
+func VerifyJSONBytes(t Failable, bs []byte, opts ...verifyOptions) {
 	t.Helper()
 	var obj map[string]interface{}
 	err := json.Unmarshal(bs, &obj)
 	if err != nil {
 		message := fmt.Sprintf("error while parsing JSON\nerror:\n  %s\nJSON:\n  %s\n", err, string(bs))
-		VerifyWithExtension(t, strings.NewReader(message), ".json")
+		Verify(t, strings.NewReader(message), alwaysOption(opts).WithExtension(".json"))
 	} else {
-		VerifyJSONStruct(t, obj)
+		VerifyJSONStruct(t, obj, opts...)
 	}
 }
 
 // VerifyMap Example:
 //   VerifyMap(t, map[string][string] { "dog": "bark" })
-func VerifyMap(t Failable, m interface{}) {
+func VerifyMap(t Failable, m interface{}, opts ...verifyOptions) {
 	t.Helper()
 	outputText := utils.PrintMap(m)
-	VerifyString(t, outputText)
+	VerifyString(t, outputText, opts...)
 }
 
 // VerifyArray Example:
 //   VerifyArray(t, []string{"dog", "cat"})
-func VerifyArray(t Failable, array interface{}) {
+func VerifyArray(t Failable, array interface{}, opts ...verifyOptions) {
 	t.Helper()
 	outputText := utils.PrintArray(array)
-	VerifyString(t, outputText)
+	VerifyString(t, outputText, opts...)
 }
 
 // VerifyAll Example:
 //   VerifyAll(t, "uppercase", []string("dog", "cat"}, func(x interface{}) string { return strings.ToUpper(x.(string)) })
-func VerifyAll(t Failable, header string, collection interface{}, transform func(interface{}) string) {
+func VerifyAll(t Failable, header string, collection interface{}, transform func(interface{}) string, opts ...verifyOptions) {
 	t.Helper()
 	if len(header) != 0 {
 		header = fmt.Sprintf("%s\n\n\n", header)
 	}
 
 	outputText := header + strings.Join(utils.MapToString(collection, transform), "\n")
-	VerifyString(t, outputText)
+	VerifyString(t, outputText, opts...)
 }
 
 type reporterCloser struct {
@@ -232,3 +263,42 @@ func getReporter() reporters.Reporter {
 func UseFolder(f string) {
 	defaultFolder = f
 }
+
+type scrubber func(s string) string
+
+// verifyOptions can be accessed via the approvals.Options() API enabling configuration of scrubbers
+type verifyOptions struct {
+	scrubbers  []scrubber
+	extWithDot string
+}
+
+// Options enables providing individual Verify functions with customisations such as scrubbers
+func Options() verifyOptions {
+	return verifyOptions{}
+}
+
+// WithRegexScrubber allows you to 'scrub' dynamic data such as timestamps within your test input
+// and replace it with a static placeholder
+func (v verifyOptions) WithRegexScrubber(scrubber *regexp.Regexp, replacer string) verifyOptions {
+	v.scrubbers = append(v.scrubbers, func(s string) string {
+		return scrubber.ReplaceAllString(s, replacer)
+	})
+	return v
+}
+
+// WithExtension overrides the default file extension (.txt) for approval files.
+func (v verifyOptions) WithExtension(extension string) verifyOptions {
+	v.extWithDot = extension
+	return v
+}
+
+func alwaysOption(opts []verifyOptions) verifyOptions {
+	var v verifyOptions
+	if len(opts) == 0 {
+		v = Options()
+	} else {
+		v = opts[0]
+	}
+
+	return v
+}

scrubber_test.go

@@ -0,0 +1,88 @@
+package approvals_test
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+	"testing"
+	"time"
+
+	approvals "github.com/approvals/go-approval-tests"
+)
+
+func TestVerifyDoesNotAcceptSeveralVerifyOptions(t *testing.T) {
+	scrubber1, _ := regexp.Compile("\\d{10}$")
+	opts1 := approvals.Options().WithRegexScrubber(scrubber1, "<time>")
+	opts2 := approvals.Options().WithRegexScrubber(scrubber1, "<time>")
+
+	m := strings.NewReader("Hello World")
+
+	defer func() { _ = recover() }()
+
+	approvals.Verify(t, m, opts1, opts2)
+	t.Errorf("Panic expected")
+}
+
+func TestVerifyMapWithRegexScrubber(t *testing.T) {
+	scrubber, _ := regexp.Compile("\\d{10}$")
+	opts := approvals.Options().WithRegexScrubber(scrubber, "<time>")
+
+	m := map[string]string{
+		"dog":  "bark",
+		"cat":  "meow",
+		"time": fmt.Sprint(time.Now().Unix()),
+	}
+	approvals.VerifyMap(t, m, opts)
+}
+
+func TestVerifyArrayWithRegexScrubber(t *testing.T) {
+	scrubber, _ := regexp.Compile("cat")
+	opts := approvals.Options().WithRegexScrubber(scrubber, "person")
+
+	xs := []string{"dog", "cat", "bird"}
+	approvals.VerifyArray(t, xs, opts)
+}
+
+func TestVerifyJSONBytesWithRegexScrubber(t *testing.T) {
+	scrubber, _ := regexp.Compile("Hello")
+	opts := approvals.Options().WithRegexScrubber(scrubber, "Hi")
+
+	jb := []byte("{ \"Greeting\": \"Hello\" }")
+	approvals.VerifyJSONBytes(t, jb, opts)
+}
+
+func TestVerifyXMLBytesWithRegexScrubber(t *testing.T) {
+	scrubber, _ := regexp.Compile("Hello")
+	opts := approvals.Options().WithRegexScrubber(scrubber, "Hi")
+
+	xmlb := []byte("<Test><Title>Hello World!</Title><Name>Peter Pan</Name><Age>100</Age></Test>")
+	approvals.VerifyXMLBytes(t, xmlb, opts)
+}
+
+func TestVerifyStringWithRegexScrubber(t *testing.T) {
+	scrubber, _ := regexp.Compile("\\d{10}$")
+	opts := approvals.Options().WithRegexScrubber(scrubber, "<now>")
+
+	s := fmt.Sprintf("The time is %v", time.Now().Unix())
+	approvals.VerifyString(t, s, opts)
+}
+
+func TestVerifyStringWithMultipleScrubbers(t *testing.T) {
+	scrubber1, _ := regexp.Compile("\\d{10}$")
+	scrubber2, _ := regexp.Compile("time")
+
+	opts := approvals.Options().
+		WithRegexScrubber(scrubber1, "<now>").
+		WithRegexScrubber(scrubber2, "<future>")
+
+	s := fmt.Sprintf("The time is %v", time.Now().Unix())
+	approvals.VerifyString(t, s, opts)
+}
+
+func TestVerifyAllWithRegexScrubber(t *testing.T) {
+	scrubber, _ := regexp.Compile("Llewellyn")
+	opts := approvals.Options().WithRegexScrubber(scrubber, "Walken")
+
+	xs := []string{"Christopher", "Llewellyn"}
+	approvals.VerifyAll(t, "uppercase", xs, func(x interface{}) string { return fmt.Sprintf("%s => %s", x, strings.ToUpper(x.(string))) }, opts)
+}

testdata/scrubber_test.TestVerifyAllWithRegexScrubber.approved.txt

@@ -0,0 +1,5 @@
+uppercase
+
+
+Christopher => CHRISTOPHER
+Walken => LLEWELLYN

testdata/scrubber_test.TestVerifyArrayWithRegexScrubber.approved.txt

@@ -0,0 +1,3 @@
+[0]=dog
+[1]=person
+[2]=bird

testdata/scrubber_test.TestVerifyDoesNotAcceptSeveralVerifyOptions.approved.txt

@@ -0,0 +1 @@
+Hello World

testdata/scrubber_test.TestVerifyJsonBytesWithRegexScrubber.approved.json

@@ -0,0 +1,3 @@
+{
+  "Greeting": "Hi"
+}

testdata/scrubber_test.TestVerifyMapWithRegexScrubber.approved.txt

@@ -0,0 +1,3 @@
+[cat]=meow
+[dog]=bark
+[time]=<time>

testdata/scrubber_test.TestVerifyStringWithMultipleScrubbers.approved.txt

@@ -0,0 +1 @@
+The <future> is <now>

testdata/scrubber_test.TestVerifyStringWithRegexScrubber.approved.txt

@@ -0,0 +1 @@
+The time is <now>

testdata/scrubber_test.TestVerifyXMLBytesWithRegexScrubber.approved.xml

@@ -0,0 +1,5 @@
+<Test>
+  <Title>Hi World!</Title>
+  <Name>Peter Pan</Name>
+  <Age>100</Age>
+</Test>