plan 9: overwrite never trashes a directory or another scanned file

1 files changed, 31 insertions, 1 deletions

diff --git a/internal/plan/conflict_test.go b/internal/plan/conflict_test.go
index bdc37af..289cd14 100644
--- a/internal/plan/conflict_test.go
+++ b/internal/plan/conflict_test.go
@@ -16,9 +16,11 @@ import (
 type fakeDisk struct {
 	exists map[string]bool
 	same   map[[2]string]bool
+	dirs   map[string]bool // existing paths that are directories
 }
 
-func (f fakeDisk) Exists(p string) bool { return f.exists[p] }
+func (f fakeDisk) Exists(p string) bool  { return f.exists[p] }
+func (f fakeDisk) Regular(p string) bool { return f.exists[p] && !f.dirs[p] }
 func (f fakeDisk) SameContent(a, b string) (bool, error) {
 	return f.same[[2]string{a, b}], nil
 }
@@ -208,6 +210,7 @@ func TestSameContentReal(t *testing.T) {
 type stubAlwaysExists struct{}
 
 func (stubAlwaysExists) Exists(string) bool                       { return true }
+func (stubAlwaysExists) Regular(string) bool                      { return true }
 func (stubAlwaysExists) SameContent(string, string) (bool, error) { return false, nil }
 
 // TestSuffixedCapsAttempts is C2: suffixed() gives up after
@@ -222,3 +225,30 @@ func TestSuffixedCapsAttempts(t *testing.T) {
 		t.Errorf("step = %+v; want Skip \"too many conflicting names\" and empty Dst", s)
 	}
 }
+
+// TestOverwriteNeverDisplacesADirectory: a hostile file named like an
+// existing directory must not have that directory trashed in its place
+// (review M4).
+func TestOverwriteNeverDisplacesADirectory(t *testing.T) {
+	dir := "/home/x/Documents/Invoices"
+	d := fakeDisk{exists: map[string]bool{dir: true}, dirs: map[string]bool{dir: true}}
+	_, skip, displaces := resolveConflict(Move, config.ConflictOverwrite, "/r/Invoices", dir, d, claimed{})
+	if displaces != "" || skip != "target is not a regular file" {
+		t.Errorf("skip %q displaces %q; want skipped, nothing displaced", skip, displaces)
+	}
+}
+
+// TestOverwriteNeverDisplacesAnotherScannedFile: a file of the same plan is
+// not trashed to make room - it may be about to move away or be acted on -
+// so the step takes a free name instead (review M4).
+func TestOverwriteNeverDisplacesAnotherScannedFile(t *testing.T) {
+	d := fakeDisk{exists: map[string]bool{"/r/a.pdf": true, "/r/b.pdf": true}}
+	in := []Input{
+		{File: file("/r", "a.pdf"), Rules: []RuleMatch{{Name: "r", Settings: config.Resolved{OnConflict: config.ConflictOverwrite}, Actions: []config.Action{act(config.Rename, "b.pdf")}}}},
+		{File: file("/r", "b.pdf"), Rules: []RuleMatch{{Name: "m", Actions: []config.Action{act(config.Move, "Out")}}}},
+	}
+	s := Build("/r", in, time.Now(), d, NewClaims())[0].Steps[0]
+	if s.Displaces != "" || s.Dst != "/r/b_1.pdf" || s.Skip != "" {
+		t.Errorf("Displaces %q Dst %q Skip %q; want no displacement and /r/b_1.pdf", s.Displaces, s.Dst, s.Skip)
+	}
+}