patchwork

package export

import (
	"os"
	"path/filepath"
	"testing"

	"git.pablomurad.com/pablo/patchwork/internal/render"
)

func TestWriteSwapsAtomically(t *testing.T) {
	dir := filepath.Join(t.TempDir(), "out")
	first := &render.Tree{Files: map[string]render.File{"a/one.json": {Body: []byte("1")}, "stale.txt": {Body: []byte("x")}}}
	if err := Write(first, dir); err != nil {
		t.Fatal(err)
	}
	second := &render.Tree{Files: map[string]render.File{"a/one.json": {Body: []byte("2")}}}
	if err := Write(second, dir); err != nil {
		t.Fatal(err)
	}
	if b, _ := os.ReadFile(filepath.Join(dir, "a", "one.json")); string(b) != "2" {
		t.Fatalf("content %q", b)
	}
	if _, err := os.Stat(filepath.Join(dir, "stale.txt")); !os.IsNotExist(err) {
		t.Fatal("a file no longer in the tree must disappear")
	}
	for _, leftover := range []string{dir + ".tmp", dir + ".old"} {
		if _, err := os.Stat(leftover); !os.IsNotExist(err) {
			t.Fatalf("%s left behind", leftover)
		}
	}
}