numfmt: implement missing --suffix option

adds support for the --suffix option from issue uutils#1280.

src/uu/numfmt/src/format.rs

@@ -220,16 +220,34 @@ fn format_string(
     options: &NumfmtOptions,
     implicit_padding: Option<isize>,
 ) -> Result<String> {
+    // strip the (optional) suffix before applying any transformation
+    let source_without_suffix = if let Some(suffix) = &options.suffix {
+        source.strip_suffix(suffix).unwrap_or(source)
+    } else {
+        source
+    };
+
     let number = transform_to(
-        transform_from(source, &options.transform.from)?,
+        transform_from(source_without_suffix, &options.transform.from)?,
         &options.transform.to,
         options.round,
     )?;
 
+    // bring back the suffix before applying padding
+    let number_with_suffix = if let Some(suffix) = &options.suffix {
+        format!("{}{}", number, suffix)
+    } else {
+        number
+    };
+
     Ok(match implicit_padding.unwrap_or(options.padding) {
-        0 => number,
-        p if p > 0 => format!("{:>padding$}", number, padding = p as usize),
-        p => format!("{:<padding$}", number, padding = p.abs() as usize),
+        0 => number_with_suffix,
+        p if p > 0 => format!("{:>padding$}", number_with_suffix, padding = p as usize),
+        p => format!(
+            "{:<padding$}",
+            number_with_suffix,
+            padding = p.abs() as usize
+        ),
     })
 }
 

src/uu/numfmt/src/numfmt.rs

@@ -142,13 +142,16 @@ fn parse_options(args: &ArgMatches) -> Result<NumfmtOptions> {
         _ => unreachable!("Should be restricted by clap"),
     };
 
+    let suffix = args.value_of(options::SUFFIX).map(|s| s.to_owned());
+
     Ok(NumfmtOptions {
         transform,
         padding,
         header,
         fields,
         delimiter,
         round,
+        suffix,
     })
 }
 
@@ -242,5 +245,14 @@ pub fn uu_app() -> App<'static, 'static> {
                 .default_value("from-zero")
                 .possible_values(&["up", "down", "from-zero", "towards-zero", "nearest"]),
         )
+        .arg(
+            Arg::with_name(options::SUFFIX)
+                .long(options::SUFFIX)
+                .help(
+                    "print SUFFIX after each formatted number, and accept \
+                    inputs optionally ending with SUFFIX",
+                )
+                .value_name("SUFFIX"),
+        )
         .arg(Arg::with_name(options::NUMBER).hidden(true).multiple(true))
 }

src/uu/numfmt/src/options.rs

@@ -11,6 +11,7 @@ pub const HEADER_DEFAULT: &str = "1";
 pub const NUMBER: &str = "NUMBER";
 pub const PADDING: &str = "padding";
 pub const ROUND: &str = "round";
+pub const SUFFIX: &str = "suffix";
 pub const TO: &str = "to";
 pub const TO_DEFAULT: &str = "none";
 
@@ -26,6 +27,7 @@ pub struct NumfmtOptions {
     pub fields: Vec<Range>,
     pub delimiter: Option<String>,
     pub round: RoundMethod,
+    pub suffix: Option<String>,
 }
 
 #[derive(Clone, Copy)]

tests/by-util/test_numfmt.rs

@@ -505,3 +505,67 @@ fn test_round() {
             .stdout_only(exp.join("\n") + "\n");
     }
 }
+
+#[test]
+fn test_suffix_is_added_if_not_supplied() {
+    new_ucmd!()
+        .args(&["--suffix=TEST"])
+        .pipe_in("1000")
+        .succeeds()
+        .stdout_only("1000TEST\n");
+}
+
+#[test]
+fn test_suffix_is_preserved() {
+    new_ucmd!()
+        .args(&["--suffix=TEST"])
+        .pipe_in("1000TEST")
+        .succeeds()
+        .stdout_only("1000TEST\n");
+}
+
+#[test]
+fn test_suffix_is_only_applied_to_selected_field() {
+    new_ucmd!()
+        .args(&["--suffix=TEST", "--field=2"])
+        .pipe_in("1000 2000 3000")
+        .succeeds()
+        .stdout_only("1000 2000TEST 3000\n");
+}
+
+#[test]
+fn test_transform_with_suffix_on_input() {
+    new_ucmd!()
+        .args(&["--suffix=TEST", "--to=si"])
+        .pipe_in("2000TEST")
+        .succeeds()
+        .stdout_only("2.0KTEST\n");
+}
+
+#[test]
+fn test_transform_without_suffix_on_input() {
+    new_ucmd!()
+        .args(&["--suffix=TEST", "--to=si"])
+        .pipe_in("2000")
+        .succeeds()
+        .stdout_only("2.0KTEST\n");
+}
+
+#[test]
+fn test_transform_with_suffix_and_delimiter() {
+    new_ucmd!()
+        .args(&["--suffix=mysuffix", "--to=si", "-d=|"])
+        .pipe_in("1000mysuffix|2000|3000")
+        .succeeds()
+        .stdout_only("1.0Kmysuffix|2000|3000\n");
+}
+
+#[test]
+fn test_suffix_with_padding() {
+    new_ucmd!()
+        .args(&["--suffix=padme", "--padding=12"])
+        .pipe_in("1000 2000 3000")
+        .succeeds()
+        .stdout_only("   1000padme 2000 3000\n");
+}
+