[object] Fix information group length calculation

- file meta information group length is not included
- refactor object smoke_test to test writing and reading
- add builder test

Author: Enet4

object/src/lib.rs

@@ -202,6 +202,8 @@ mod tests {
 
     #[test]
     fn smoke_test() {
+        const FILE_NAME: &str = ".smoke-test.dcm";
+
         let meta = FileMetaTableBuilder::new()
             .transfer_syntax(dicom_transfer_syntax_registry::entries::EXPLICIT_VR_LITTLE_ENDIAN.uid())
             .media_storage_sop_class_uid("1.2.840.10008.5.1.4.1.1.1")
@@ -212,7 +214,12 @@ mod tests {
         let obj = RootDicomObject::new_empty_with_meta(
             meta);
 
-        obj.write_to_file(".smoke-test.dcm").unwrap();
-        let _ = std::fs::remove_file(".smoke-test.dcm");
+        obj.write_to_file(FILE_NAME).unwrap();
+
+        let obj2 = RootDicomObject::open_file(FILE_NAME).unwrap();
+
+        assert_eq!(obj, obj2);
+
+        let _ = std::fs::remove_file(FILE_NAME);
     }
 }

object/src/meta.rs

@@ -528,8 +528,10 @@ impl FileMetaTableBuilder {
         let information_group_length = match self.information_group_length {
             Some(e) => e,
             None => {
-                // determine the expected meta group size based on the given fields
-                12 + 14 +
+                    // determine the expected meta group size based on the given fields.
+                    // FileMetaInformationGroupLength is not included here
+
+                    14 +
                     8 + dicom_len(&media_storage_sop_class_uid) +
                     8 + dicom_len(&media_storage_sop_instance_uid) +
                     8 + dicom_len(&transfer_syntax) +
@@ -563,7 +565,7 @@ impl FileMetaTableBuilder {
 
 #[cfg(test)]
 mod tests {
-    use super::FileMetaTable;
+    use super::{FileMetaTableBuilder, FileMetaTable};
     use dicom_core::value::Value;
     use dicom_core::{dicom_value, DataElement, Tag, VR};
 
@@ -646,6 +648,39 @@ mod tests {
         assert_eq!(table, gt);
     }
 
+    #[test]
+    fn create_meta_table_with_builder() {
+        let table = FileMetaTableBuilder::new()
+            .information_version([0, 1])
+            .media_storage_sop_class_uid("1.2.840.10008.5.1.4.1.1.1")
+            .media_storage_sop_instance_uid("1.2.3.4.5.12345678.1234567890.1234567.123456789.1234567")
+            .transfer_syntax("1.2.840.10008.1.2.1")
+            .implementation_class_uid("1.2.345.6.7890.1.234")
+            .implementation_version_name("RUSTY_DICOM_269")
+            .source_application_entity_title("")
+            .build()
+            .unwrap();
+
+        let gt = FileMetaTable {
+            information_group_length: 200,
+            information_version: [0u8, 1u8],
+            media_storage_sop_class_uid: "1.2.840.10008.5.1.4.1.1.1\0".to_owned(),
+            media_storage_sop_instance_uid:
+                "1.2.3.4.5.12345678.1234567890.1234567.123456789.1234567\0".to_owned(),
+            transfer_syntax: "1.2.840.10008.1.2.1\0".to_owned(),
+            implementation_class_uid: "1.2.345.6.7890.1.234".to_owned(),
+            implementation_version_name: Some("RUSTY_DICOM_269 ".to_owned()),
+            source_application_entity_title: Some("".to_owned()),
+            sending_application_entity_title: None,
+            receiving_application_entity_title: None,
+            private_information_creator_uid: None,
+            private_information: None,
+        };
+
+        assert_eq!(table.information_group_length, gt.information_group_length);
+        assert_eq!(table, gt);
+    }
+
     #[test]
     fn read_meta_table_into_iter() {
         let table = FileMetaTable {