Add format test, fix dump block and bitmap bug

prodos/bitmap.go

@@ -9,14 +9,23 @@ func ReadVolumeBitmap(file *os.File) []byte {
 
 	volumeHeader := parseVolumeHeader(headerBlock)
 
-	bitmap := make([]byte, volumeHeader.TotalBlocks/8+1)
+	totalBitmapBytes := volumeHeader.TotalBlocks / 8
+	if volumeHeader.TotalBlocks%8 > 0 {
+		totalBitmapBytes++
+	}
 
-	totalBitmapBlocks := volumeHeader.TotalBlocks / 8 / 512
+	bitmap := make([]byte, totalBitmapBytes)
 
-	for i := 0; i <= totalBitmapBlocks; i++ {
+	totalBitmapBlocks := totalBitmapBytes / 512
+
+	if totalBitmapBytes%512 > 0 {
+		totalBitmapBlocks++
+	}
+
+	for i := 0; i < totalBitmapBlocks; i++ {
 		bitmapBlock := ReadBlock(file, i+volumeHeader.BitmapStartBlock)
 
-		for j := 0; j < 512; j++ {
+		for j := 0; j < 512 && i*512+j < totalBitmapBytes; j++ {
 			bitmap[i*512+j] = bitmapBlock[j]
 		}
 	}
@@ -92,6 +101,17 @@ func findFreeBlocks(volumeBitmap []byte, numberOfBlocks int) []int {
 	return nil
 }
 
+func getFreeBlockCount(volumeBitmap []byte, totalBlocks int) int {
+	freeBlockCount := 0
+
+	for i := 0; i < totalBlocks; i++ {
+		if checkFreeBlockInVolumeBitmap(volumeBitmap, i) {
+			freeBlockCount++
+		}
+	}
+	return freeBlockCount
+}
+
 func markBlockInVolumeBitmap(volumeBitmap []byte, blockNumber int) {
 	bitToChange := blockNumber % 8
 	byteToChange := blockNumber / 8

prodos/format_test.go

@@ -0,0 +1,49 @@
+package prodos
+
+import (
+	"fmt"
+	"os"
+	"testing"
+)
+
+func TestCreateVolume(t *testing.T) {
+	var tests = []struct {
+		blocks         int
+		wantVolumeName string
+		wantFreeBlocks int
+	}{
+		{65535, "MAX", 65513},
+		{65500, "ALMOST.MAX", 65478},
+		{280, "FLOPPY", 273},
+	}
+
+	for _, tt := range tests {
+		testname := fmt.Sprintf("%d", tt.blocks)
+		t.Run(testname, func(t *testing.T) {
+			fileName := os.TempDir() + "test-volume.hdv"
+			os.Remove(fileName)
+			CreateVolume(fileName, tt.wantVolumeName, tt.blocks)
+
+			file, err := os.Open(fileName)
+			if err != nil {
+				t.Error(err)
+			}
+			volumeHeader, _, fileEntries := ReadDirectory(file, "")
+			if volumeHeader.VolumeName != tt.wantVolumeName {
+				t.Errorf("got volume name %s, want %s", volumeHeader.VolumeName, tt.wantVolumeName)
+			}
+			if volumeHeader.TotalBlocks != tt.blocks {
+				t.Errorf("got total blocks %d, want %d", volumeHeader.TotalBlocks, tt.blocks)
+			}
+			if len(fileEntries) > 0 {
+				t.Errorf("got files %d, want 0", len(fileEntries))
+			}
+
+			volumeBitmap := ReadVolumeBitmap(file)
+			freeBlockCount := getFreeBlockCount(volumeBitmap, tt.blocks)
+			if freeBlockCount != tt.wantFreeBlocks {
+				t.Errorf("got free blocks: %d, want %d", freeBlockCount, tt.wantFreeBlocks)
+			}
+		})
+	}
+}

prodos/text.go

@@ -120,7 +120,7 @@ func DumpBlock(buffer []byte) {
 		}
 		for j := i; j < i+16; j++ {
 			c := buffer[j] & 127
-			if c >= 32 {
+			if c >= 32 && c < 127 {
 				fmt.Printf("%c", c)
 			} else {
 				fmt.Printf(".")