diff --git a/src/bbox.rs b/src/bbox.rs
index f64e76c..ac467de 100644
--- a/src/bbox.rs
+++ b/src/bbox.rs
@@ -332,9 +332,7 @@ fn parse_cstr(input: &[u8]) -> IResult<&[u8], String> {
 
 #[cfg(test)]
 mod tests {
-    use std::io::Read;
-
-    use crate::testkit::open_sample;
+    use crate::testkit::read_sample;
 
     use super::*;
     use nom::error::make_error;
@@ -342,9 +340,7 @@ mod tests {
 
     #[test_case("exif.heic")]
     fn travel_heic(path: &str) {
-        let mut reader = open_sample(path).unwrap();
-        let mut buf = Vec::new();
-        reader.read_to_end(buf.as_mut()).unwrap();
+        let buf = read_sample(path).unwrap();
         let mut boxes = Vec::new();
 
         let (remain, bbox) = travel_while(&buf, |bbox| {
@@ -389,9 +385,7 @@ mod tests {
 
     #[test_case("meta.mov")]
     fn travel_mov(path: &str) {
-        let mut reader = open_sample(path).unwrap();
-        let mut buf = Vec::new();
-        reader.read_to_end(buf.as_mut()).unwrap();
+        let buf = read_sample(path).unwrap();
         let mut boxes = Vec::new();
 
         let (remain, bbox) = travel_while(&buf, |bbox| {
@@ -444,9 +438,7 @@ mod tests {
 
     #[test_case("meta.mp4")]
     fn travel_mp4(path: &str) {
-        let mut reader = open_sample(path).unwrap();
-        let mut buf = Vec::new();
-        reader.read_to_end(buf.as_mut()).unwrap();
+        let buf = read_sample(path).unwrap();
         let mut boxes = Vec::new();
 
         let (remain, bbox) = travel_while(&buf, |bbox| {
@@ -531,16 +523,7 @@ mod tests {
     // atom.
     #[test_case("meta.mp4")]
     fn find_android_gps_box(path: &str) {
-        let mut f = open_sample(path).unwrap();
-        let mut buf = Vec::new();
-        f.read_to_end(&mut buf).unwrap();
-
-        // let (_, bbox) = travel_while(&buf, |b| b.box_type() != "moov").unwrap();
-        // println!("bbox: {:?}", bbox.header);
-        // let (_, bbox) = travel_while(bbox.body_data(), |b| b.box_type() != "udta").unwrap();
-        // println!("bbox: {:?}", bbox.header);
-        // let (_, bbox) = travel_while(bbox.body_data(), |b| b.box_type() != "©xyz").unwrap();
-
+        let buf = read_sample(path).unwrap();
         let (_, bbox) = find_box(&buf, "moov/udta/©xyz").unwrap();
         let bbox = bbox.unwrap();
         // println!("bbox: {:?}", bbox.header);
diff --git a/src/bbox/ilst.rs b/src/bbox/ilst.rs
index aa59eda..95930e4 100644
--- a/src/bbox/ilst.rs
+++ b/src/bbox/ilst.rs
@@ -127,19 +127,14 @@ fn parse_value(type_code: u32, data: &[u8]) -> crate::Result<EntryValue> {
 
 #[cfg(test)]
 mod tests {
-    use std::io::Read;
-
-    use crate::{bbox::travel_while, testkit::open_sample};
+    use crate::{bbox::travel_while, testkit::read_sample};
 
     use super::*;
     use test_case::test_case;
 
     #[test_case("meta.mov")]
     fn ilst_box(path: &str) {
-        let mut f = open_sample(path).unwrap();
-        let mut buf = Vec::new();
-        f.read_to_end(&mut buf).unwrap();
-
+        let buf = read_sample(path).unwrap();
         let (_, bbox) = travel_while(&buf, |b| b.box_type() != "moov").unwrap();
         let bbox = bbox.unwrap();
         let (_, bbox) = travel_while(bbox.body_data(), |b| b.box_type() != "meta").unwrap();
@@ -168,10 +163,7 @@ mod tests {
 
     #[test_case("embedded-in-heic.mov")]
     fn heic_mov_ilst(path: &str) {
-        let mut f = open_sample(path).unwrap();
-        let mut buf = Vec::new();
-        f.read_to_end(&mut buf).unwrap();
-
+        let buf = read_sample(path).unwrap();
         let (_, moov) = travel_while(&buf, |b| b.box_type() != "moov").unwrap();
         let moov = moov.unwrap();
         let (_, meta) = travel_while(moov.body_data(), |b| b.box_type() != "meta").unwrap();
diff --git a/src/bbox/keys.rs b/src/bbox/keys.rs
index 90d4c39..93378da 100644
--- a/src/bbox/keys.rs
+++ b/src/bbox/keys.rs
@@ -68,11 +68,9 @@ impl KeyEntry {
 
 #[cfg(test)]
 mod tests {
-    use std::io::Read;
-
     use crate::{
         bbox::{travel_while, ParseBox},
-        testkit::open_sample,
+        testkit::read_sample,
     };
 
     use super::*;
@@ -80,10 +78,7 @@ mod tests {
 
     #[test_case("meta.mov", 4133, 0x01b9, 0xc9)]
     fn keys_box(path: &str, moov_size: u64, meta_size: u64, keys_size: u64) {
-        let mut f = open_sample(path).unwrap();
-        let mut buf = Vec::new();
-        f.read_to_end(&mut buf).unwrap();
-
+        let buf = read_sample(path).unwrap();
         let (_, moov) = travel_while(&buf, |b| b.box_type() != "moov").unwrap();
         let moov = moov.unwrap();
         let (_, meta) = travel_while(moov.body_data(), |b| b.box_type() != "meta").unwrap();
@@ -132,10 +127,7 @@ mod tests {
 
     #[test_case("embedded-in-heic.mov", 0x1790, 0x0372, 0x1ce)]
     fn heic_mov_keys(path: &str, moov_size: u64, meta_size: u64, keys_size: u64) {
-        let mut f = open_sample(path).unwrap();
-        let mut buf = Vec::new();
-        f.read_to_end(&mut buf).unwrap();
-
+        let buf = read_sample(path).unwrap();
         let (_, moov) = travel_while(&buf, |b| b.box_type() != "moov").unwrap();
         let moov = moov.unwrap();
         let (_, meta) = travel_while(moov.body_data(), |b| b.box_type() != "meta").unwrap();
diff --git a/src/bbox/meta.rs b/src/bbox/meta.rs
index d8ca959..237a0e3 100644
--- a/src/bbox/meta.rs
+++ b/src/bbox/meta.rs
@@ -121,20 +121,14 @@ pub struct ItemLocation {
 
 #[cfg(test)]
 mod tests {
-    use std::io::Read;
-
-    use crate::{bbox::travel_while, testkit::open_sample};
+    use crate::{bbox::travel_while, testkit::read_sample};
 
     use super::*;
     use test_case::test_case;
 
     #[test_case("exif.heic", 2618)]
     fn meta(path: &str, meta_size: usize) {
-        let mut reader = open_sample(path).unwrap();
-        let mut buf = Vec::new();
-        reader.read_to_end(buf.as_mut()).unwrap();
-        assert_eq!(buf.len() as u64, reader.metadata().unwrap().len());
-
+        let buf = read_sample(path).unwrap();
         let (_, bbox) = travel_while(&buf, |bbox| {
             // println!("got {}", bbox.header.box_type);
             bbox.box_type() != "meta"
diff --git a/src/bbox/mvhd.rs b/src/bbox/mvhd.rs
index 9b081fc..19fc998 100644
--- a/src/bbox/mvhd.rs
+++ b/src/bbox/mvhd.rs
@@ -82,11 +82,9 @@ impl ParseBody<MvhdBox> for MvhdBox {
 
 #[cfg(test)]
 mod tests {
-    use std::io::Read;
-
     use crate::{
         bbox::{travel_while, ParseBox},
-        testkit::open_sample,
+        testkit::read_sample,
     };
 
     use super::*;
@@ -106,9 +104,7 @@ mod tests {
         1063
     )]
     fn mvhd_box(path: &str, time_utc: &str, time_east8: &str, milliseconds: u32) {
-        let mut f = open_sample(path).unwrap();
-        let mut buf = Vec::new();
-        f.read_to_end(&mut buf).unwrap();
+        let buf = read_sample(path).unwrap();
 
         let (_, bbox) = travel_while(&buf, |b| b.box_type() != "moov").unwrap();
         let bbox = bbox.unwrap();
diff --git a/src/bbox/tkhd.rs b/src/bbox/tkhd.rs
index 52891cc..fb91dd7 100644
--- a/src/bbox/tkhd.rs
+++ b/src/bbox/tkhd.rs
@@ -143,9 +143,7 @@ fn find_video_track(input: &[u8]) -> crate::Result<Option<BoxHolder>> {
 
 #[cfg(test)]
 mod tests {
-    use std::io::Read;
-
-    use crate::{bbox::travel_while, testkit::open_sample};
+    use crate::{bbox::travel_while, testkit::read_sample};
 
     use super::*;
     use test_case::test_case;
@@ -153,9 +151,7 @@ mod tests {
     #[test_case("meta.mov", 720, 1280)]
     #[test_case("meta.mp4", 1920, 1080)]
     fn tkhd_box(path: &str, width: u32, height: u32) {
-        let mut f = open_sample(path).unwrap();
-        let mut buf = Vec::new();
-        f.read_to_end(&mut buf).unwrap();
+        let buf = read_sample(path).unwrap();
 
         let (_, bbox) = travel_while(&buf, |b| b.box_type() != "moov").unwrap();
         let bbox = bbox.unwrap();