fix: nil checks from fuzzers

bundle.go

@@ -99,6 +99,10 @@ func (b *Bundle) Validate() error {
 // build creates a valid Bundle by building  BundleControl. An error is returned if
 // the bundle being built has invalid records.
 func (b *Bundle) build() error {
+	if b == nil {
+		return nil
+	}
+
 	// Requires a valid BundleHeader
 	if err := b.BundleHeader.Validate(); err != nil {
 		return err

bundleHeader.go

@@ -177,6 +177,9 @@ func (bh *BundleHeader) String() string {
 // Validate performs imagecashletter format rule checks on the record and returns an error if not Validated
 // The first error encountered is returned and stops the parsing.
 func (bh *BundleHeader) Validate() error {
+	if bh == nil {
+		return nil
+	}
 	if err := bh.fieldInclusion(); err != nil {
 		return err
 	}
@@ -204,6 +207,9 @@ func (bh *BundleHeader) Validate() error {
 // fieldInclusion validate mandatory fields are not default values. If fields are
 // invalid the Electronic Exchange will be returned.
 func (bh *BundleHeader) fieldInclusion() error {
+	if bh == nil {
+		return nil
+	}
 	if bh.recordType == "" {
 		return &FieldError{FieldName: "recordType",
 			Value: bh.recordType,

file.go

@@ -255,7 +255,11 @@ func (f *File) Create() error {
 			}
 
 			if err := b.build(); err != nil {
-				return fmt.Errorf("building bundle %s: %w", b.BundleHeader.BundleSequenceNumber, err)
+				bundleSeq := b.ID
+				if b.BundleHeader != nil {
+					bundleSeq = b.BundleHeader.BundleSequenceNumber
+				}
+				return fmt.Errorf("building bundle %s: %w", bundleSeq, err)
 			}
 		}
 	}

test/fuzz/testdata/fuzz/FuzzReaderWriterJSON/2024-10-28-3.txt

@@ -0,0 +1,2 @@
+go test fuzz v1
+string("{\"CAshLetters\":[{}]}")

test/fuzz/testdata/fuzz/FuzzReaderWriterJSON/2024-10-28-5.txt

@@ -0,0 +1,2 @@
+go test fuzz v1
+string("{\"CAshLetters\":[{}]}")