| 1 | package worktree |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "os" |
| 6 | "path/filepath" |
| 7 | "strings" |
| 8 | "testing" |
| 9 | ) |
| 10 | |
| 11 | // hostileHooksPath builds the machine that made the hook tests destructive: a |
| 12 | // user-level git config pointing core.hooksPath at a directory the developer |
| 13 | // owns. The hook planted there records that it ran and exits 0, so it changes |
| 14 | // nothing except leave evidence - a hook that failed would be indistinguishable |
| 15 | // from an unrelated broken commit. |
| 16 | // |
| 17 | // Returns the hook's path and the marker it writes when git runs it. |
| 18 | func hostileHooksPath(t *testing.T) (hook, marker string) { |
| 19 | t.Helper() |
| 20 | dir := t.TempDir() |
| 21 | hook = filepath.Join(dir, "pre-commit") |
| 22 | marker = filepath.Join(t.TempDir(), "ambient-hook-ran") |
| 23 | script := "#!/bin/sh\nprintf ran > '" + marker + "'\nexit 0\n" |
| 24 | if err := os.WriteFile(hook, []byte(script), 0o755); err != nil { |
| 25 | t.Fatal(err) |
| 26 | } |
| 27 | config := filepath.Join(t.TempDir(), "gitconfig") |
| 28 | if err := os.WriteFile(config, []byte("[core]\n\thooksPath = "+dir+"\n"), 0o644); err != nil { |
| 29 | t.Fatal(err) |
| 30 | } |
| 31 | // Set before requireGit, exactly as the ambient environment would be, so |
| 32 | // the isolation has to win rather than merely arrive first. |
| 33 | t.Setenv("GIT_CONFIG_GLOBAL", config) |
| 34 | return hook, marker |
| 35 | } |
| 36 | |
| 37 | // The write side. Any test that asks git where the pre-commit hook lives and |
| 38 | // then writes one must be answered with a path inside its own repository. This |
| 39 | // asserts the property rather than the two call sites that rely on it, so a |
| 40 | // third one cannot be added outside its cover. |
| 41 | func TestHookPathResolvesInsideTheTestRepository(t *testing.T) { |
| 42 | hook, _ := hostileHooksPath(t) |
| 43 | before, err := os.ReadFile(hook) |
| 44 | if err != nil { |
| 45 | t.Fatal(err) |
| 46 | } |
| 47 | |
| 48 | requireGit(t) |
| 49 | repo := initRepo(t) |
| 50 | |
| 51 | resolved := gitTest(t, repo, "rev-parse", "--git-path", "hooks/pre-commit") |
| 52 | if !filepath.IsAbs(resolved) { |
| 53 | resolved = filepath.Join(repo, resolved) |
| 54 | } |
| 55 | if !strings.HasPrefix(resolved, repo) { |
| 56 | t.Fatalf("hook path resolved outside the test repository: %s", resolved) |
| 57 | } |
| 58 | |
| 59 | after, err := os.ReadFile(hook) |
| 60 | if err != nil { |
| 61 | t.Fatalf("the developer's hook is gone: %v", err) |
| 62 | } |
| 63 | if string(after) != string(before) { |
| 64 | t.Fatalf("the developer's hook was rewritten:\n%s", after) |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | // The read side, and the reason the hook tests could pass for the wrong reason. |
| 69 | // The package spawns git through runGit, which inherits os.Environ(), so the |
| 70 | // isolation has to reach the code under test and not only the helpers: a hook |
| 71 | // configured outside the repository must not run during the commits these |
| 72 | // tests make. |
| 73 | func TestCodeUnderTestDoesNotRunAnAmbientHook(t *testing.T) { |
| 74 | _, marker := hostileHooksPath(t) |
| 75 | |
| 76 | requireGit(t) |
| 77 | repo := initRepo(t) |
| 78 | if err := os.WriteFile(filepath.Join(repo, "change.txt"), []byte("change\n"), 0o644); err != nil { |
| 79 | t.Fatal(err) |
| 80 | } |
| 81 | if _, stderr, err := runGit(context.Background(), opened(t, repo), "add", "change.txt"); err != nil { |
| 82 | t.Fatalf("git add: %v%s", err, stderrSuffix(stderr)) |
| 83 | } |
| 84 | if _, stderr, err := runGit(context.Background(), opened(t, repo), |
| 85 | "-c", "user.name=Reasonix Test", "-c", "user.email=reasonix@example.invalid", |
| 86 | "commit", "-m", "change"); err != nil { |
| 87 | t.Fatalf("git commit: %v%s", err, stderrSuffix(stderr)) |
| 88 | } |
| 89 | |
| 90 | if _, err := os.Stat(marker); !os.IsNotExist(err) { |
| 91 | t.Fatalf("a hook outside the repository ran during the test's own commit, stat err = %v", err) |
| 92 | } |
| 93 | } |
| 94 |