Port str upcase (#404)

* Port str upcase

* Switch to to_uppercase to support more characters than only ASCII

crates/nu-command/src/default_context.rs

@@ -148,6 +148,7 @@ pub fn create_default_context() -> EngineState {
             StrStartsWith,
             StrReverse,
             StrSubstring,
+            StrUpcase,
             StrTrim,
             Sys,
             Table,

crates/nu-command/src/strings/str_/mod.rs

@@ -13,6 +13,7 @@ mod rpad;
 mod starts_with;
 mod substring;
 mod trim;
+mod upcase;
 
 pub use capitalize::SubCommand as StrCapitalize;
 pub use case::*;
@@ -29,3 +30,4 @@ pub use rpad::SubCommand as StrRpad;
 pub use starts_with::SubCommand as StrStartsWith;
 pub use substring::SubCommand as StrSubstring;
 pub use trim::Trim as StrTrim;
+pub use upcase::SubCommand as StrUpcase;

crates/nu-command/src/strings/str_/upcase.rs

@@ -0,0 +1,109 @@
+use nu_engine::CallExt;
+use nu_protocol::ast::Call;
+use nu_protocol::ast::CellPath;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value};
+
+#[derive(Clone)]
+pub struct SubCommand;
+
+impl Command for SubCommand {
+    fn name(&self) -> &str {
+        "str upcase"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("str upcase").rest(
+            "rest",
+            SyntaxShape::CellPath,
+            "optionally upcase text by column paths",
+        )
+    }
+
+    fn usage(&self) -> &str {
+        "upcases text"
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        operate(engine_state, stack, call, input)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Upcase contents",
+            example: "'nu' | str upcase",
+            result: Some(Value::test_string("NU")),
+        }]
+    }
+}
+
+fn operate(
+    engine_state: &EngineState,
+    stack: &mut Stack,
+    call: &Call,
+    input: PipelineData,
+) -> Result<PipelineData, ShellError> {
+    let head = call.head;
+    let column_paths: Vec<CellPath> = call.rest(engine_state, stack, 0)?;
+    input.map(
+        move |v| {
+            if column_paths.is_empty() {
+                action(&v, head)
+            } else {
+                let mut ret = v;
+                for path in &column_paths {
+                    let r =
+                        ret.update_cell_path(&path.members, Box::new(move |old| action(old, head)));
+                    if let Err(error) = r {
+                        return Value::Error { error };
+                    }
+                }
+                ret
+            }
+        },
+        engine_state.ctrlc.clone(),
+    )
+}
+
+fn action(input: &Value, head: Span) -> Value {
+    match input {
+        Value::String { val: s, .. } => Value::String {
+            val: s.to_uppercase(),
+            span: head,
+        },
+        other => {
+            let got = format!("Expected string but got {}", other.get_type());
+            Value::Error {
+                error: ShellError::UnsupportedInput(got, head),
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use super::{action, SubCommand};
+
+    #[test]
+    fn test_examples() {
+        use crate::test_examples;
+
+        test_examples(SubCommand {})
+    }
+
+    #[test]
+    fn upcases() {
+        let word = Value::test_string("andres");
+
+        let actual = action(&word, Span::unknown());
+        let expected = Value::test_string("ANDRES");
+        assert_eq!(actual, expected);
+    }
+}