Separate Container Workdir from host Workdir (#635)

* Separate Container Workdir from Host Workdir

* Add delegated component to MacOS Test

* Lint: Remove leading newline

* Fix trailing path issue

pkg/runner/runner.go

@@ -4,6 +4,10 @@ import (
 	"context"
 	"fmt"
 	"io/ioutil"
+	"path/filepath"
+	"regexp"
+	"runtime"
+	"strings"
 
 	"github.com/nektos/act/pkg/common"
 	"github.com/nektos/act/pkg/model"
@@ -36,6 +40,46 @@ type Config struct {
 	UseGitIgnore          bool              // controls if paths in .gitignore should not be copied into container, default true
 }
 
+// Resolves the equivalent host path inside the container
+// This is required for windows and WSL 2 to translate things like C:\Users\Myproject to /mnt/users/Myproject
+// For use in docker volumes and binds
+func (config *Config) containerPath(path string) string {
+	if runtime.GOOS == "windows" && strings.Contains(path, "/") {
+		log.Error("You cannot specify linux style local paths (/mnt/etc) on Windows as it does not understand them.")
+		return ""
+	}
+
+	abspath, err := filepath.Abs(path)
+	if err != nil {
+		log.Error(err)
+		return ""
+	}
+
+	// Test if the path is a windows path
+	windowsPathRegex := regexp.MustCompile(`^([a-zA-Z]):\\(.+)$`)
+	windowsPathComponents := windowsPathRegex.FindStringSubmatch(abspath)
+
+	// Return as-is if no match
+	if windowsPathComponents == nil {
+		return abspath
+	}
+
+	// Convert to WSL2-compatible path if it is a windows path
+	// NOTE: Cannot use filepath because it will use the wrong path separators assuming we want the path to be windows
+	// based if running on Windows, and because we are feeding this to Docker, GoLang auto-path-translate doesn't work.
+	driveLetter := strings.ToLower(windowsPathComponents[1])
+	translatedPath := strings.ReplaceAll(windowsPathComponents[2], `\`, `/`)
+	// Should make something like /mnt/c/Users/person/My Folder/MyActProject
+	result := strings.Join([]string{"/mnt", driveLetter, translatedPath}, `/`)
+	return result
+}
+
+// Resolves the equivalent host path inside the container
+// This is required for windows and WSL 2 to translate things like C:\Users\Myproject to /mnt/users/Myproject
+func (config *Config) ContainerWorkdir() string {
+	return config.containerPath(config.Workdir)
+}
+
 type runnerImpl struct {
 	config    *Config
 	eventJSON string