Implement package-local tests

backend/test/generate_backend_tests.go

@@ -0,0 +1,111 @@
+// +build ignore
+
+package main
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"regexp"
+	"text/template"
+	"time"
+)
+
+var data struct {
+	Package   string
+	Funcs     []string
+	Timestamp string
+}
+
+var testTemplate = `
+// DO NOT EDIT!
+// generated at {{ .Timestamp }}
+package {{ .Package }}
+
+import (
+	"testing"
+
+	"github.com/restic/restic/backend/test"
+)
+
+{{ range $f := .Funcs }}func Test{{ $f }}(t *testing.T){ test.{{ $f }}(t) }
+{{ end }}
+`
+
+var testFile = flag.String("testfile", "../test/tests.go", "file to search test functions in")
+var outputFile = flag.String("output", "backend_test.go", "output file to write generated code to")
+
+func errx(err error) {
+	if err == nil {
+		return
+	}
+
+	fmt.Fprintf(os.Stderr, "error: %v\n", err)
+	os.Exit(1)
+}
+
+var funcRegex = regexp.MustCompile(`^func\s+([A-Z].*)\s*\(`)
+
+func findTestFunctions() (funcs []string) {
+	f, err := os.Open(*testFile)
+	errx(err)
+
+	sc := bufio.NewScanner(f)
+	for sc.Scan() {
+		match := funcRegex.FindStringSubmatch(sc.Text())
+		if len(match) > 0 {
+			funcs = append(funcs, match[1])
+		}
+	}
+
+	if err := sc.Err(); err != nil {
+		log.Fatalf("Error scanning file: %v", err)
+	}
+
+	errx(f.Close())
+	return funcs
+}
+
+func generateOutput(wr io.Writer, data interface{}) {
+	t := template.Must(template.New("backendtest").Parse(testTemplate))
+
+	cmd := exec.Command("gofmt")
+	cmd.Stdout = wr
+	in, err := cmd.StdinPipe()
+	errx(err)
+	errx(cmd.Start())
+	errx(t.Execute(in, data))
+	errx(in.Close())
+	errx(cmd.Wait())
+}
+
+func init() {
+	flag.Parse()
+}
+
+func main() {
+	dir, err := os.Getwd()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Getwd() %v\n", err)
+		os.Exit(1)
+	}
+
+	packageName := filepath.Base(dir)
+
+	f, err := os.Create(*outputFile)
+	errx(err)
+
+	data.Package = packageName + "_test"
+	data.Funcs = findTestFunctions()
+	data.Timestamp = time.Now().Format("2006-02-01 15:04:05 -0700 MST")
+	generateOutput(f, data)
+
+	errx(f.Close())
+
+	fmt.Printf("wrote backend tests for package %v\n", packageName)
+}