internal/gitutil/subjects_test.go

 1package gitutil
 2
 3import (
 4	"os/exec"
 5	"strings"
 6	"testing"
 7)
 8
 9func TestSubjects(t *testing.T) {
10	dir := t.TempDir()
11	git(t, dir, "init", "-q", "-b", "main")
12
13	write(t, dir, "a", "one\n")
14	git(t, dir, "add", ".")
15	git(t, dir, "commit", "-qm", "first thing")
16	first := rev(t, dir, "HEAD")
17
18	write(t, dir, "a", "two\n")
19	git(t, dir, "commit", "-qam", "second thing")
20	second := rev(t, dir, "HEAD")
21
22	got := Subjects(dir, []string{second, first})
23	if got[first] != "first thing" || got[second] != "second thing" {
24		t.Fatalf("Subjects = %v", got)
25	}
26
27	// A build outlives the commit it ran on when a branch is
28	// force-pushed. The shas that do resolve still come back.
29	gone := strings.Repeat("1", 40)
30	got = Subjects(dir, []string{gone, first})
31	if got[first] != "first thing" {
32		t.Errorf("a missing sha lost the rest: %v", got)
33	}
34	if _, ok := got[gone]; ok {
35		t.Errorf("resolved a sha that is not there: %v", got)
36	}
37
38	if Subjects(dir, nil) != nil {
39		t.Error("empty sha list should not run git")
40	}
41}
42
43func rev(t *testing.T, dir, ref string) string {
44	t.Helper()
45	out, err := exec.Command("git", "-C", dir, "rev-parse", ref).Output()
46	if err != nil {
47		t.Fatal(err)
48	}
49	return strings.TrimSpace(string(out))
50}