Used to have a function for appending png filenames. Now more general.

ackwork/ackwork_test.go

@@ -138,20 +138,40 @@ func TestPlot(t *testing.T) {
 	}
 }
 
-func TestMakepngName(t *testing.T) {
+func TestSetSuffix (t *testing.T) {
 	var tdata = []struct {
-		in  string
-		out string
+		in, suffix, want string
 	}{
-		{"boo", "boo.png"},
-		{"boo.", "boo.png"},
-		{"a.png", "a.png"},
-		{"/boo/foo/a.PNG", "/boo/foo/a.PNG"},
-		{"a/b/c/d.svg", "a/b/c/d.png"},
+		{"boo.", ".csv", "boo.csv"}, //xxx
+		{"boo", "csv", "boo.csv"},
+		{"boo.", "csv", "boo.csv"},
+		{"boo", ".csv", "boo.csv"},
+		{"boo.csv", ".csv", "boo.csv"},
+		{"/boo/blah/boo", ".csv", "/boo/blah/boo.csv"},
+		{"/a/b/c.svg", ".png", "/a/b/c.png"},
+		{"boo.", "", "boo"},
+		{"boo", "", "boo"},
 	}
+
+	for _, s := range tdata {
+		if tmp, err := SetSuffix (s.in, s.suffix); err != nil {
+			t.Fatal ("setSuffix error handling", s)
+		} else {
+			if tmp != s.want {
+				t.Fatal ("Wanted", s.want, "got", tmp, "working on", s)
+			}
+		}
+	}
+}
+
+// Check that errors are generated
+func TestSetSuffixErr (t *testing.T) {
+	var tdata = []struct {in, suffix string}{
+		{"", ""},
+		{".", ""} }
 	for _, s := range tdata {
-		if tmp := MakepngName (s.in); tmp != s.out {
-			t.Fatal ("Wanted", s.out, "got", tmp)
+		if _, err := SetSuffix (s.in, s.suffix); err == nil {
+			t.Fatal ("setSuffix should return error on", s)
 		}
 	}
 }

ackwork/dorun.go

@@ -71,7 +71,10 @@ func setupRun(mcPrm *mcPrm, cprm *cprm) error {
 		return err
 	}
 	if mcPrm.fPltName != "" {
-		mcPrm.fPltName = makepngName(mcPrm.fPltName)
+		var err error
+		if mcPrm.fPltName, err = setSuffix(mcPrm.fPltName, ".png"); err != nil {
+			return fmt.Errorf("plot filename: %w", err)
+		}
 		if cprm.fPlt, err = os.Create(mcPrm.fPltName); err != nil {
 			return err
 		}

ackwork/export_test.go

 package ackwork
 
-var MakepngName = makepngName
+var SetSuffix = setSuffix

ackwork/plot.go

@@ -6,6 +6,7 @@
 package ackwork
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"math"
@@ -20,7 +21,7 @@ import (
 // If it ends in something else, replace the ending with png.
 // We have stalinistically decided that we will only write png output.
 // svg is nicer, but the files can become silly big.
-func makepngName(fname string) string {
+func XmakepngName(fname string) string {
 	const dotpng = ".png"
 	ext := filepath.Ext(fname)
 	switch ext {
@@ -36,6 +37,36 @@ func makepngName(fname string) string {
 	return "hello"
 }
 
+// setSuffix takes a name and makes sure the desired suffix is at the end
+// of the filename.
+func setSuffix(fname, suffix string) (string, error) {
+	if len(fname) == 0 {
+		return "", errors.New("setSuffix given empty fname")
+	}
+	if suffix == "" { // no suffix might not be an error. Just
+		if fname[len(fname)-1] == '.' { // remove any trailing dot
+			fname = fname[0 : len(fname)-1]
+		}
+		if len(fname) > 0 {
+			return fname, nil
+		}
+		return "", errors.New("setSuffix got empty filename")
+	}
+
+	if suffix[0] != '.' {
+		suffix = "." + suffix
+	}
+	oldExt := filepath.Ext(fname)
+	switch oldExt {
+	case suffix:
+		return fname, nil
+	case "":
+		return fname + suffix, nil
+	default:
+		return fname[0:len(fname)-len(oldExt)] + suffix, nil
+	}
+}
+
 // maketicks gives reasonable default tick locations
 func maketicks(axisDscrpt axticks.AxisDscrpt, prcsn int) []chart.Tick {
 	xmin, delta, prcsn := axisDscrpt.Xmin, axisDscrpt.Delta, axisDscrpt.Prcsn