diff --git a/tests/integers.rs b/tests/integers.rs
index 2809af5..17ab7e3 100644
--- a/tests/integers.rs
+++ b/tests/integers.rs
@@ -35,6 +35,15 @@ fn read_char_3() {
     assert!(iof::ReadInto::<u32>::try_read_char(&mut reader).is_err());
 }
 
+#[test]
+#[should_panic = "failed to read a non-whitespace character before EOF"]
+fn read_char_empty() {
+    let reader = Cursor::new("".as_bytes());
+    let mut reader = InputStream::new(reader);
+
+    let _: u32 = reader.read_char();
+}
+
 #[test]
 #[should_panic = "invalid digit found in string"]
 fn read_sign_error() {
diff --git a/tests/string.rs b/tests/string.rs
index a301bf0..1c5df07 100644
--- a/tests/string.rs
+++ b/tests/string.rs
@@ -45,14 +45,14 @@ fn read_line() {
 
 #[test]
 fn read_remained_line() {
-    let reader = Cursor::new("There are 4 strings.\n\n".as_bytes());
+    let reader = Cursor::new("There are 4 strings.\nThere are 3 lines.\n".as_bytes());
     let mut reader = InputStream::new(reader);
 
     let a: String = reader.read_remained_line();
     assert_eq!(a, "There are 4 strings.");
 
     let b: String = reader.read_remained_line();
-    assert_eq!(b, "");
+    assert_eq!(b, "There are 3 lines.");
 
     let c: String = reader.read_remained_line();
     assert_eq!(c, "");
@@ -60,7 +60,7 @@ fn read_remained_line() {
     let d: String = reader.read_remained_line();
     assert_eq!(d, "");
 
-    assert!(iof::ReadInto::<String>::try_read(&mut reader).is_err());
+    assert!(iof::ReadInto::<String>::try_read_line(&mut reader).is_err());
 }
 
 #[test]
@@ -73,6 +73,15 @@ fn read_line_spaces() {
     assert!(iof::ReadInto::<String>::try_read(&mut reader).is_err());
 }
 
+#[test]
+#[should_panic = "number too large to fit in target type"]
+fn read_remained_line_from_str_err() {
+    let reader = Cursor::new("123456789".as_bytes());
+    let mut reader = InputStream::new(reader);
+
+    let _: u16 = reader.read_remained_line();
+}
+
 #[test]
 #[should_panic = "failed to read a non-whitespace character before EOF"]
 fn read_line_failure() {
diff --git a/tests/tuple.rs b/tests/tuple.rs
index 7d453e4..b8215d1 100644
--- a/tests/tuple.rs
+++ b/tests/tuple.rs
@@ -13,7 +13,7 @@ fn read_tuple_3() {
 }
 
 #[test]
-fn read_tuple_3_err() {
+fn try_read_tuple_3_from_str_err() {
     let reader = Cursor::new("1 2 -3".as_bytes());
     let mut reader = InputStream::new(reader);
 
@@ -21,6 +21,15 @@ fn read_tuple_3_err() {
     assert!(vec.is_err());
 }
 
+#[test]
+#[should_panic = "invalid digit found in string"]
+fn read_tuple_3_from_str_err() {
+    let reader = Cursor::new("1 2 -3".as_bytes());
+    let mut reader = InputStream::new(reader);
+
+    let _: (u32, u32, u32) = reader.read_tuple();
+}
+
 #[test]
 fn read_tuple_12() {
     let reader = Cursor::new("1 2 3 4 5 6 7 8 9 10 11 12".as_bytes());
diff --git a/tests/vec.rs b/tests/vec.rs
index 207af4f..7e28389 100644
--- a/tests/vec.rs
+++ b/tests/vec.rs
@@ -13,6 +13,15 @@ fn read_n_1() {
     assert!(iof::ReadInto::<u32>::try_read_n(&mut reader, 1).is_err());
 }
 
+#[test]
+#[should_panic = "invalid digit found in string"]
+fn read_n_from_str_err() {
+    let reader = Cursor::new("1 -2 -3".as_bytes());
+    let mut reader = InputStream::new(reader);
+
+    let _: Vec<u32> = reader.read_n(3);
+}
+
 #[test]
 fn read_all() -> anyhow::Result<()> {
     let reader = Cursor::new("3 2 1".as_bytes());