Fix negative value file size for "into filesize" (issue #12396) (#12443)

# Description
Add support for using negative values file size for `into filesize`.
This will help in sorting the file size if negative values are also
passed.

**Before**

![image](https://github.com/nushell/nushell/assets/43441496/e115b4b3-7526-4379-8dc0-f4f4e44839a1)
**After**

![image](https://github.com/nushell/nushell/assets/43441496/4a75fb40-ebe6-46eb-b9d2-55f37db7a6fa)

# User-Facing Changes
- User can now sort negative filesize also

# Tests + Formatting
- 🟢 toolkit fmt
- 🟢 toolkit clippy
- 🟢 toolkit test
- 🟢 toolkit test stdlib

# After Submitting

---------

Co-authored-by: Priyank Singh <priyank.singh@soroco.com>

crates/nu-command/src/conversions/into/filesize.rs

@@ -107,6 +107,11 @@ impl Command for SubCommand {
                 example: "4KB | into filesize",
                 result: Some(Value::test_filesize(4000)),
             },
+            Example {
+                description: "Convert string with unit to filesize",
+                example: "'-1KB' | into filesize",
+                result: Some(Value::test_filesize(-1000)),
+            },
         ]
     }
 }
@@ -140,7 +145,21 @@ fn int_from_string(a_string: &str, span: Span) -> Result<i64, ShellError> {
     // Now that we know the locale, get the thousands separator and remove it
     // so strings like 1,123,456 can be parsed as 1123456
     let no_comma_string = a_string.replace(locale.separator(), "");
-    match no_comma_string.trim().parse::<bytesize::ByteSize>() {
+    let clean_string = no_comma_string.trim();
+
+    // Hadle negative file size
+    if let Some(stripped_string) = clean_string.strip_prefix('-') {
+        match stripped_string.parse::<bytesize::ByteSize>() {
+            Ok(n) => Ok(-(n.as_u64() as i64)),
+            Err(_) => Err(ShellError::CantConvert {
+                to_type: "int".into(),
+                from_type: "string".into(),
+                span,
+                help: None,
+            }),
+        }
+    } else {
+        match clean_string.parse::<bytesize::ByteSize>() {
             Ok(n) => Ok(n.0 as i64),
             Err(_) => Err(ShellError::CantConvert {
                 to_type: "int".into(),
@@ -150,6 +169,7 @@ fn int_from_string(a_string: &str, span: Span) -> Result<i64, ShellError> {
             }),
         }
     }
+}
 
 #[cfg(test)]
 mod test {

crates/nu-command/tests/commands/into_filesize.rs

@@ -61,3 +61,10 @@ fn into_filesize_negative_filesize() {
 
     assert!(actual.out.contains("-3.0 KiB"));
 }
+
+#[test]
+fn into_negative_filesize() {
+    let actual = nu!("'-1' | into filesize");
+
+    assert!(actual.out.contains("-1 B"));
+}