support discarding submodule changes

pkg/commands/submodules.go

@@ -0,0 +1,66 @@
+package commands
+
+import (
+	"bufio"
+	"os"
+	"regexp"
+)
+
+// .gitmodules looks like this:
+// [submodule "mysubmodule"]
+//   path = blah/mysubmodule
+//   url = git@github.com:subbo.git
+
+func (c *GitCommand) GetSubmoduleConfigs() ([]*SubmoduleConfig, error) {
+	file, err := os.Open(".gitmodules")
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, nil
+		}
+		return nil, err
+	}
+
+	scanner := bufio.NewScanner(file)
+	scanner.Split(bufio.ScanLines)
+
+	firstMatch := func(str string, regex string) (string, bool) {
+		re := regexp.MustCompile(regex)
+		matches := re.FindStringSubmatch(str)
+
+		if len(matches) > 0 {
+			return matches[1], true
+		} else {
+			return "", false
+		}
+	}
+
+	configs := []*SubmoduleConfig{}
+	for scanner.Scan() {
+		line := scanner.Text()
+
+		if name, ok := firstMatch(line, `\[submodule "(.*)"\]`); ok {
+			configs = append(configs, &SubmoduleConfig{Name: name})
+			continue
+		}
+
+		if len(configs) > 0 {
+			lastConfig := configs[len(configs)-1]
+
+			if path, ok := firstMatch(line, `\s*path\s*=\s*(.*)\s*`); ok {
+				lastConfig.Path = path
+			} else if url, ok := firstMatch(line, `\s*url\s*=\s*(.*)\s*`); ok {
+				lastConfig.Url = url
+			}
+		}
+	}
+
+	return configs, nil
+}
+
+func (c *GitCommand) SubmoduleStash(config *SubmoduleConfig) error {
+	return c.OSCommand.RunCommand("git -C %s stash --include-untracked", config.Path)
+}
+
+func (c *GitCommand) SubmoduleReset(config *SubmoduleConfig) error {
+	return c.OSCommand.RunCommand("git submodule update --force %s", config.Name)
+}