Enumerate examples/ for which SVG file contents may need to change

Refactor for tidiness.

examples_test.go

@@ -2,15 +2,15 @@ package goat
 
 import (
 	"bytes"
+	"errors"
 	"flag"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
 	"testing"
-
-	qt "github.com/frankban/quicktest"
 )
 
 var (
@@ -23,9 +23,7 @@ var (
 )
 
 // XX  TXT source file suite is limited to a single file -- "circuits.txt"
-func TestExamplesStableOutput(t *testing.T) {
-	c := qt.New(t)
-
+func TestExampleStableOutput(t *testing.T) {
 	var previous string
 	for i := 0; i < 3; i++ {
 		in, err := os.Open(filepath.Join(basePath, "circuits.txt"))
@@ -36,7 +34,7 @@ func TestExamplesStableOutput(t *testing.T) {
 		BuildAndWriteSVG(in, &out, "black", "white")
 		in.Close()
 		if i > 0 && previous != out.String() {
-			c.Fail()
+			t.FailNow()
 		}
 		previous = out.String()
 
@@ -49,84 +47,87 @@ func TestExamples(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	var buff *bytes.Buffer
-	if write == nil {
+	if *write {
+		writeExamples(t, filenames)
+	} else {
 		t.Logf("Verifying equality of current SVG with examples/ references.\n")
+		verifyExamples(t, filenames)
 	}
-	var failures int
+}
+
+
+func writeExamples(t *testing.T, filenames []string) {
 	for _, name := range filenames {
 		in := getIn(name)
-		var out io.WriteCloser
-		if *write {
-			out = getOut(name)
-		} else {
-			if buff == nil {
-				buff = &bytes.Buffer{}
-			} else {
-				buff.Reset()
-			}
-			out = struct {
-				io.Writer
-				io.Closer
-			}{
-				buff,
-				io.NopCloser(nil),
-			}
-		}
-
+		out := getOut(name)
 		BuildAndWriteSVG(in, out, *svgColorLightScheme, *svgColorDarkScheme)
-
 		in.Close()
 		out.Close()
+	}
+}
 
-		if buff != nil {
-			golden, err := getOutString(name)
-			if err != nil {
-				t.Log(err)
-			}
-			if newStr := buff.String(); newStr != golden {
-				// Skip complaint if the modification timestamp of the .txt file
-				// source is fresher than that of the .svg?
-				//   => NO, Any .txt difference might be an editing mistake.
-
-				t.Logf("Content mismatch for %s. Length was %d, expected %d",
-					toSVGFilename(name), buff.Len(), len(golden))
-				for i:=0; i<min(len(golden), len(newStr)); i++ {
-					if newStr[i] != golden[i] {
-						t.Logf("Differing runes at offset %d: new='%#v' reference='%#v'\n",
-							i, newStr[i], golden[i])
-						break
-					}
-				}
-				t.Logf("Generated contents do not match existing %s",
-					toSVGFilename(name))
-				failures++
-			} else {
-				if testing.Verbose() {
-					t.Logf("Existing and generated contents match %s\n",
-						toSVGFilename(name))
-				}
-			}
-			in.Close()
-			out.Close()
+func verifyExamples(t *testing.T, filenames []string) {
+	var failures []string
+	for _, name := range filenames {
+		in := getIn(name)
+		buff := &bytes.Buffer{}
+		BuildAndWriteSVG(in, buff, *svgColorLightScheme, *svgColorDarkScheme)
+		in.Close()
+		if nil != compareSVG(t, buff, name) {
+			failures = append(failures, name)
 		}
+
 	}
-	if failures > 0 {
+	if len(failures) > 0 {
 		t.Logf(`Failed to verify contents of %d .svg files
-Consider:
-	%s`,
-			failures,
-			"$ go test -run TestExamples -v -args -write")
+Failing files:`,
+			len(failures))
+		for _, name := range failures {
+			svgFile := toSVGFilename(name)
+			fmt.Printf("\t\t%s\n", svgFile)
+		}
 		t.FailNow()
 	}
 }
 
+func compareSVG(t *testing.T, buff *bytes.Buffer, fileName string) error {
+	golden, err := getOutString(fileName)
+	if err != nil {
+		t.Log(err)
+	}
+	if newStr := buff.String(); newStr != golden {
+		// Skip complaint if the modification timestamp of the .txt file
+		// source is fresher than that of the .svg?
+		//   => NO, Any .txt difference might be an editing mistake.
+
+		t.Logf("Content mismatch for %s. Length was %d, expected %d",
+			toSVGFilename(fileName), buff.Len(), len(golden))
+		for i:=0; i<min(len(golden), len(newStr)); i++ {
+			if newStr[i] != golden[i] {
+				t.Logf("Differing runes at offset %d: new='%#v' reference='%#v'\n",
+					i, newStr[i], golden[i])
+				break
+			}
+		}
+		t.Logf("Generated contents do not match existing %s",
+			toSVGFilename(fileName))
+		return errors.New("Generated contents do not match existing")
+	} else {
+		if testing.Verbose() {
+			t.Logf("Existing and generated contents match %s\n",
+				toSVGFilename(fileName))
+		}
+	}
+	return nil
+}
+
 func BenchmarkComplicated(b *testing.B) {
 	in := getIn(filepath.FromSlash("examples/complicated.txt"))
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
 		BuildAndWriteSVG(in, io.Discard, "black", "white")
 	}
+	in.Close()
 }
 
 const basePath string = "examples"
@@ -150,6 +151,7 @@ func getOut(txtFilename string) io.WriteCloser {
 func getOutString(txtFilename string) (string, error) {
 	b, err := ioutil.ReadFile(toSVGFilename(txtFilename))
 	if err != nil {
+		// XX  Simply panic rather than return an error?
 		return "", err
 	}
 	// XX  Why are there RETURN characters in contents of the .SVG files?