sync: make --track-renames tests less fragile by using rename stat

Before this change these tests attempted to measure transfers and
checks in lieu of having a rename statistic with a very complicated
heuristic.

The change switches over to using the rename statistic which should be
100% reliable.

fs/sync/sync_test.go

@@ -1067,64 +1067,9 @@ func TestSyncWithTrackRenames(t *testing.T) {
 
 	fstest.CheckItems(t, r.Fremote, f1, f2)
 
-	// As currently there is no Fs interface providing number of chunks
+	// Check we renamed something
-	// in a file, this test depends on the well-known names of test remotes.
+	renames := accounting.GlobalStats().Renames(0)
-	remote := r.Fremote.Name()
+	assert.Equal(t, canTrackRenames, renames != 0, fmt.Sprintf("canTrackRenames=%v, renames=%d", canTrackRenames, renames))
-
-	// Union remote can Move but returns CantMove error.
-	moveAsCopyDelete := r.Fremote.Features().Move == nil || remote == "TestUnion"
-
-	chunker := strings.HasPrefix(remote, "TestChunker")
-	wrappedMoveAsCopyDelete := chunker && strings.HasSuffix(remote, "S3")
-
-	chunk3b := chunker && strings.Contains(remote, "Chunk3b")            // chunker with 3 byte chunks
-	chunk50b := chunker && strings.Contains(remote, "Chunk50b")          // chunker with 50 byte chunks
-	chunkDefault := chunker && !strings.Contains(remote, "ChunkerChunk") // default big chunk size
-	chunkBig := chunk50b || chunkDefault                                 // file is smaller than chunk size
-
-	// Verify number of checks for a toy 14 byte file.
-	// The order of cases matters!
-	var checks int
-	switch {
-	case canTrackRenames && chunk3b:
-		checks = 8 // chunker makes extra checks for each small chunk
-	case canTrackRenames && chunkBig:
-		checks = 4 // chunker makes 1 extra check for a single big chunk
-	case canTrackRenames && moveAsCopyDelete:
-		checks = 4 // 2 file checks + 1 move + 1 delete
-	case canTrackRenames:
-		checks = 3 // 2 file checks + 1 move
-	case !chunker:
-		checks = 2 // 2 file checks on a generic non-chunking remote
-	case chunk3b:
-		checks = 6 // chunker makes extra checks for each small chunk
-	case chunkBig && wrappedMoveAsCopyDelete:
-		checks = 4 // one more extra check because S3 emulates Move as Copy+Delete
-	case chunkBig:
-		checks = 3 // chunker makes 1 extra check for a single big chunk
-	default:
-		checks = -1 // skip verification for chunker with unknown chunk size
-	}
-	if checks != -1 { // "-1" allows remotes to bypass this check
-		assert.Equal(t, int64(checks), accounting.GlobalStats().GetChecks())
-	}
-
-	// Verify number of copy operations for a toy 14 byte file.
-	// The order of cases matters!
-	var copies int64
-	switch {
-	case canTrackRenames && moveAsCopyDelete:
-		copies = 1 // 1 copy
-	case canTrackRenames:
-		copies = 0 // 0 copy
-	case chunkBig && wrappedMoveAsCopyDelete:
-		copies = 2 // extra Copy because S3 emulates Move as Copy+Delete.
-	default:
-		copies = 1
-	}
-	if copies != -1 { // "-1" allows remotes to bypass this check
-		assert.Equal(t, copies, accounting.GlobalStats().GetTransfers())
-	}
 }
 
 func TestParseRenamesStrategyModtime(t *testing.T) {
@@ -1191,64 +1136,9 @@ func TestSyncWithTrackRenamesStrategyModtime(t *testing.T) {
 
 	fstest.CheckItems(t, r.Fremote, f1, f2)
 
-	// As currently there is no Fs interface providing number of chunks
+	// Check we renamed something
-	// in a file, this test depends on the well-known names of test remotes.
+	renames := accounting.GlobalStats().Renames(0)
-	remote := r.Fremote.Name()
+	assert.Equal(t, canTrackRenames, renames != 0, fmt.Sprintf("canTrackRenames=%v, renames=%d", canTrackRenames, renames))
-
-	// Union remote can Move but returns CantMove error.
-	moveAsCopyDelete := r.Fremote.Features().Move == nil || remote == "TestUnion"
-
-	chunker := strings.HasPrefix(remote, "TestChunker")
-	wrappedMoveAsCopyDelete := chunker && strings.HasSuffix(remote, "S3")
-
-	chunk3b := chunker && strings.Contains(remote, "Chunk3b")            // chunker with 3 byte chunks
-	chunk50b := chunker && strings.Contains(remote, "Chunk50b")          // chunker with 50 byte chunks
-	chunkDefault := chunker && !strings.Contains(remote, "ChunkerChunk") // default big chunk size
-	chunkBig := chunk50b || chunkDefault                                 // file is smaller than chunk size
-
-	// Verify number of checks for a toy 14 byte file.
-	// The order of cases matters!
-	var checks int
-	switch {
-	case canTrackRenames && chunk3b:
-		checks = 8 // chunker makes extra checks for each small chunk
-	case canTrackRenames && chunkBig:
-		checks = 4 // chunker makes 1 extra check for a single big chunk
-	case canTrackRenames && moveAsCopyDelete:
-		checks = 4 // 2 file checks + 1 move + 1 delete
-	case canTrackRenames:
-		checks = 3 // 2 file checks + 1 move
-	case !chunker:
-		checks = 2 // 2 file checks on a generic non-chunking remote
-	case chunk3b:
-		checks = 6 // chunker makes extra checks for each small chunk
-	case chunkBig && wrappedMoveAsCopyDelete:
-		checks = 4 // one more extra check because S3 emulates Move as Copy+Delete
-	case chunkBig:
-		checks = 3 // chunker makes 1 extra check for a single big chunk
-	default:
-		checks = -1 // skip verification for chunker with unknown chunk size
-	}
-	if checks != -1 { // "-1" allows remotes to bypass this check
-		assert.Equal(t, int64(checks), accounting.GlobalStats().GetChecks())
-	}
-
-	// Verify number of copy operations for a toy 14 byte file.
-	// The order of cases matters!
-	var copies int64
-	switch {
-	case canTrackRenames && moveAsCopyDelete:
-		copies = 1 // 1 copy
-	case canTrackRenames:
-		copies = 0 // 0 copy
-	case chunkBig && wrappedMoveAsCopyDelete:
-		copies = 2 // extra Copy because S3 emulates Move as Copy+Delete.
-	default:
-		copies = 1
-	}
-	if copies != -1 { // "-1" allows remotes to bypass this check
-		assert.Equal(t, copies, accounting.GlobalStats().GetTransfers())
-	}
 }
 
 func toyFileTransfers(r *fstest.Run) int64 {