Made partially implemented mod parsing safe

cmd/grnc-bind/binder/gomod.go

@@ -0,0 +1,71 @@
+package binder
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/graniticio/granitic/v2/logging"
+	"log"
+	"os"
+	"os/exec"
+	"path/filepath"
+)
+
+//ParseModFile tries to parse the mod file in the supplied directory and returns an error if parsing failed
+func ParseModFile(d string, l logging.Logger) (*ModFile, error) {
+
+	cwd, _ := os.Getwd()
+	defer os.Chdir(cwd)
+
+	if err := os.Chdir(d); err != nil {
+		return nil, fmt.Errorf("unable to change directory to %s: %s", d, err.Error())
+	}
+
+	goExec, err := exec.LookPath("go")
+
+	if err != nil {
+		return nil, fmt.Errorf("could not find go on your path. Make sure it is available in your OS PATH environment variable")
+	}
+
+	cmd := exec.Command(goExec, "mod", "edit", "--json")
+
+	stdout, err := cmd.StdoutPipe()
+
+	if err != nil {
+		return nil, err
+	}
+
+	if err := cmd.Start(); err != nil {
+		log.Fatal(err)
+	}
+
+	m := make(map[string]interface{})
+
+	if err := json.NewDecoder(stdout).Decode(&m); err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Println(m)
+
+	mf := new(ModFile)
+
+	return mf, nil
+
+}
+
+// ModFile represents a mod file on disk
+type ModFile struct {
+}
+
+// CheckModFileExists makes sure that a go.mod file exists in the supplied directory
+func CheckModFileExists(d string) bool {
+
+	f := filepath.Join(d, "go.mod")
+
+	info, err := os.Stat(f)
+
+	if os.IsNotExist(err) || info.IsDir() {
+		return false
+	}
+
+	return true
+}

cmd/grnc-bind/binder/testdata/validmod/go.mod

@@ -0,0 +1,11 @@
+module github.com/my/thing
+
+go 1.14
+
+require (
+	github.com/some/dependency v1.2.3
+	github.com/another/dependency/v4 v4.0.0
+)
+
+
+replace github.com/some/dependency => ../some

go.mod

@@ -1 +1,3 @@
 module github.com/graniticio/granitic/v2
+
+go 1.14