tests/df: test 3 digit rounding

Signed-off-by: Alexander Bakanovskii <[email protected]>

Author: bakanovskii

src/uu/df/src/blocks.rs

@@ -243,6 +243,34 @@ mod tests {
 
     use crate::blocks::{BlockSize, SuffixType, to_magnitude_and_suffix};
 
+    #[test]
+    fn test_to_magnitude_and_suffix_rounding() {
+        assert_eq!(
+            to_magnitude_and_suffix(999440, SuffixType::Si, true),
+            "1.0MB"
+        );
+        assert_eq!(
+            to_magnitude_and_suffix(819200, SuffixType::Si, true),
+            "820kB"
+        );
+        assert_eq!(
+            to_magnitude_and_suffix(819936, SuffixType::Si, true),
+            "820kB"
+        );
+        assert_eq!(
+            to_magnitude_and_suffix(818400, SuffixType::Si, true),
+            "819kB"
+        );
+        assert_eq!(
+            to_magnitude_and_suffix(817600, SuffixType::Si, true),
+            "818kB"
+        );
+        assert_eq!(
+            to_magnitude_and_suffix(817200, SuffixType::Si, true),
+            "818kB"
+        );
+    }
+
     #[test]
     fn test_to_magnitude_and_suffix_add_tracing_zero() {
         assert_eq!(to_magnitude_and_suffix(1024, SuffixType::Iec, true), "1.0K");

tests/by-util/test_df.rs

@@ -151,6 +151,18 @@ fn test_df_trailing_zeros() {
         .stdout_does_not_match(&Regex::new("\\s[1-9][A-Z]").unwrap());
 }
 
+#[test]
+fn test_df_rounding() {
+    use regex::Regex;
+
+    new_ucmd!()
+        .arg("-H")
+        .arg("--output=size,used")
+        .arg("--total")
+        .succeeds()
+        .stdout_does_not_match(&Regex::new("\\s\\d{3}\\.\\d[A-Z]").unwrap());
+}
+
 #[test]
 fn test_df_output_overridden() {
     let expected = if cfg!(target_os = "macos") {