Add Persistent Task Invalidation

cache/git.go

@@ -0,0 +1,57 @@
+package cache
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"strings"
+
+	"github.com/samsarahq/taskrunner/shell"
+)
+
+type gitClient struct {
+	shellRun shell.ShellRun
+}
+
+func stripStdout(buf bytes.Buffer) string {
+	return strings.Trim(buf.String(), "\n")
+}
+
+func splitStdout(buf bytes.Buffer) []string {
+	return strings.Split(stripStdout(buf), "\n")
+}
+
+func (g gitClient) currentCommit(ctx context.Context) (commitHash string, err error) {
+	var buffer bytes.Buffer
+	if err := g.shellRun(ctx, "git rev-parse HEAD", shell.Stdout(&buffer)); err != nil {
+		return "", err
+	}
+
+	return stripStdout(buffer), nil
+}
+
+func (g gitClient) diff(ctx context.Context, commitHash string) (modifiedFiles []string, error error) {
+	var buffer bytes.Buffer
+	if err := g.shellRun(ctx, fmt.Sprintf("git diff --name-only %s", commitHash), shell.Stdout(&buffer)); err != nil {
+		return nil, err
+	}
+
+	return splitStdout(buffer), nil
+}
+
+func (g gitClient) uncomittedFiles(ctx context.Context) (newFiles []string, modifiedFiles []string, err error) {
+	var buffer bytes.Buffer
+	if err := g.shellRun(ctx, "git status --porcelain", shell.Stdout(&buffer)); err != nil {
+		return nil, nil, err
+	}
+
+	for _, statusLine := range splitStdout(buffer) {
+		if strings.HasPrefix(statusLine, "??") {
+			newFiles = append(newFiles, statusLine[3:])
+		} else {
+			modifiedFiles = append(modifiedFiles, statusLine[3:])
+		}
+	}
+
+	return newFiles, modifiedFiles, nil
+}