str plugin can capitalize and trim strings. (#1652)

* Str plugin can capitalize.

* Str plugin can trim.

crates/nu_plugin_str/src/nu/mod.rs

@@ -15,9 +15,11 @@ impl Plugin for Str {
     fn config(&mut self) -> Result<Signature, ShellError> {
         Ok(Signature::build("str")
             .desc("Apply string function. Optional use the column of a table")
+            .switch("capitalize", "capitalizes the string", Some('c'))
             .switch("downcase", "convert string to lowercase", Some('d'))
             .switch("upcase", "convert string to uppercase", Some('U'))
             .switch("to-int", "convert string to integer", Some('i'))
+            .switch("trim", "trims the string", Some('t'))
             .named(
                 "replace",
                 SyntaxShape::String,
@@ -49,6 +51,12 @@ impl Plugin for Str {
     fn begin_filter(&mut self, call_info: CallInfo) -> Result<Vec<ReturnValue>, ShellError> {
         let args = call_info.args;
 
+        if args.has("trim") {
+            self.for_trim();
+        }
+        if args.has("capitalize") {
+            self.for_capitalize();
+        }
         if args.has("downcase") {
             self.for_downcase();
         }

crates/nu_plugin_str/src/nu/tests.rs

@@ -56,6 +56,20 @@ mod integration {
             });
     }
 
+    #[test]
+    fn picks_up_trim_flag() {
+        plugin(&mut Str::new())
+            .args(CallStub::new().with_long_flag("trim").create())
+            .setup(|plugin, _| plugin.expect_action(Action::Trim));
+    }
+
+    #[test]
+    fn picks_up_capitalize_flag() {
+        plugin(&mut Str::new())
+            .args(CallStub::new().with_long_flag("capitalize").create())
+            .setup(|plugin, _| plugin.expect_action(Action::Capitalize));
+    }
+
     #[test]
     fn picks_up_downcase_flag() {
         plugin(&mut Str::new())
@@ -169,6 +183,44 @@ mod integration {
         Ok(())
     }
 
+    #[test]
+    fn trims_the_input_using_the_field_passed_as_parameter() -> Result<(), ShellError> {
+        let run = plugin(&mut Str::new())
+            .args(
+                CallStub::new()
+                    .with_long_flag("trim")
+                    .with_parameter("name")?
+                    .create(),
+            )
+            .input(structured_sample_record("name", "andres   "))
+            .setup(|_, _| {})
+            .test();
+
+        let actual = expect_return_value_at(run, 0);
+
+        assert_eq!(get_data(actual, "name"), string("andres"));
+        Ok(())
+    }
+
+    #[test]
+    fn capitalizes_the_input_using_the_field_passed_as_parameter() -> Result<(), ShellError> {
+        let run = plugin(&mut Str::new())
+            .args(
+                CallStub::new()
+                    .with_long_flag("capitalize")
+                    .with_parameter("name")?
+                    .create(),
+            )
+            .input(structured_sample_record("name", "andres"))
+            .setup(|_, _| {})
+            .test();
+
+        let actual = expect_return_value_at(run, 0);
+
+        assert_eq!(get_data(actual, "name"), string("Andres"));
+        Ok(())
+    }
+
     #[test]
     fn downcases_the_input_using_the_field_passed_as_parameter() -> Result<(), ShellError> {
         let run = plugin(&mut Str::new())
@@ -261,6 +313,30 @@ mod integration {
         assert_eq!(actual, string("JOANDREHUDA"));
     }
 
+    #[test]
+    fn trims_the_input() {
+        let run = plugin(&mut Str::new())
+            .args(CallStub::new().with_long_flag("trim").create())
+            .input(unstructured_sample_record("andres   "))
+            .setup(|_, _| {})
+            .test();
+
+        let actual = expect_return_value_at(run, 0);
+        assert_eq!(actual, string("andres"));
+    }
+
+    #[test]
+    fn capitalizes_the_input() {
+        let run = plugin(&mut Str::new())
+            .args(CallStub::new().with_long_flag("capitalize").create())
+            .input(unstructured_sample_record("andres"))
+            .setup(|_, _| {})
+            .test();
+
+        let actual = expect_return_value_at(run, 0);
+        assert_eq!(actual, string("Andres"));
+    }
+
     #[test]
     fn downcases_the_input() {
         let run = plugin(&mut Str::new())

crates/nu_plugin_str/src/strutils.rs

@@ -10,12 +10,14 @@ use std::cmp;
 
 #[derive(Debug, Eq, PartialEq)]
 pub enum Action {
+    Capitalize,
     Downcase,
     Upcase,
     ToInteger,
     Substring(usize, usize),
     Replace(ReplaceAction),
     ToDateTime(String),
+    Trim,
 }
 
 #[derive(Debug, Eq, PartialEq)]
@@ -38,6 +40,22 @@ impl Str {
 
     fn apply(&self, input: &str) -> Result<UntaggedValue, ShellError> {
         let applied = match self.action.as_ref() {
+            Some(Action::Trim) => UntaggedValue::string(input.trim()),
+            Some(Action::Capitalize) => {
+                let mut capitalized = String::new();
+
+                for (idx, character) in input.chars().enumerate() {
+                    let out = if idx == 0 {
+                        character.to_uppercase().to_string()
+                    } else {
+                        character.to_lowercase().to_string()
+                    };
+
+                    capitalized.push_str(&out);
+                }
+
+                UntaggedValue::string(capitalized)
+            }
             Some(Action::Downcase) => UntaggedValue::string(input.to_ascii_lowercase()),
             Some(Action::Upcase) => UntaggedValue::string(input.to_ascii_uppercase()),
             Some(Action::Substring(s, e)) => {
@@ -101,6 +119,14 @@ impl Str {
         self.add_action(Action::ToInteger);
     }
 
+    pub fn for_capitalize(&mut self) {
+        self.add_action(Action::Capitalize);
+    }
+
+    pub fn for_trim(&mut self) {
+        self.add_action(Action::Trim);
+    }
+
     pub fn for_downcase(&mut self) {
         self.add_action(Action::Downcase);
     }
@@ -151,7 +177,7 @@ impl Str {
     }
 
     pub fn usage() -> &'static str {
-        "Usage: str field [--downcase|--upcase|--to-int|--substring \"start,end\"|--replace|--find-replace [pattern replacement]]]"
+        "Usage: str field [--capitalize|--downcase|--upcase|--to-int|--substring \"start,end\"|--replace|--find-replace [pattern replacement]|to-date-time|--trim]"
     }
 
     pub fn strutils(&self, value: Value) -> Result<Value, ShellError> {
@@ -216,6 +242,22 @@ pub mod tests {
     use super::Str;
     use nu_plugin::test_helpers::value::{int, string};
 
+    #[test]
+    fn trim() -> Result<(), Box<dyn std::error::Error>> {
+        let mut strutils = Str::new();
+        strutils.for_trim();
+        assert_eq!(strutils.apply("andres ")?, string("andres").value);
+        Ok(())
+    }
+
+    #[test]
+    fn capitalize() -> Result<(), Box<dyn std::error::Error>> {
+        let mut strutils = Str::new();
+        strutils.for_capitalize();
+        assert_eq!(strutils.apply("andres")?, string("Andres").value);
+        Ok(())
+    }
+
     #[test]
     fn downcases() -> Result<(), Box<dyn std::error::Error>> {
         let mut strutils = Str::new();

docs/commands/str.md

@@ -47,4 +47,18 @@ Consumes either a single value or a table and converts the provided data to a st
 ─────────
        6
 ━━━━━━━━━
-```
+
+> echo "nu" | str --capitalize
+━━━━━━━━━
+ <value>
+─────────
+      Nu
+━━━━━━━━━
+
+> echo "Nu    " | str --trim
+━━━━━━━━━
+ <value>
+─────────
+      Nu
+━━━━━━━━━
+```

tests/plugins/core_str.rs

@@ -9,7 +9,7 @@ fn can_only_apply_one() {
         "open caco3_plastics.csv | first 1 | str origin --downcase --upcase"
     );
 
-    assert!(actual.contains(r#"--downcase|--upcase|--to-int|--substring "start,end"|--replace|--find-replace [pattern replacement]]"#));
+    assert!(actual.contains(r#"--capitalize|--downcase|--upcase|--to-int|--substring "start,end"|--replace|--find-replace [pattern replacement]|to-date-time|--trim]"#));
 }
 
 #[test]
@@ -34,8 +34,48 @@ fn acts_without_passing_field() {
 }
 
 #[test]
-fn downcases() {
+fn trims() {
     Playground::setup("plugin_str_test_2", |dirs, sandbox| {
+        sandbox.with_files(vec![FileWithContent(
+            "sample.toml",
+            r#"
+                    [dependency]
+                    name = "nu "
+                "#,
+        )]);
+
+        let actual = nu!(
+            cwd: dirs.test(),
+            "open sample.toml | str dependency.name --trim | get dependency.name | echo $it"
+        );
+
+        assert_eq!(actual, "nu");
+    })
+}
+
+#[test]
+fn capitalizes() {
+    Playground::setup("plugin_str_test_3", |dirs, sandbox| {
+        sandbox.with_files(vec![FileWithContent(
+            "sample.toml",
+            r#"
+                    [dependency]
+                    name = "nu"
+                "#,
+        )]);
+
+        let actual = nu!(
+            cwd: dirs.test(),
+            "open sample.toml | str dependency.name --capitalize | get dependency.name | echo $it"
+        );
+
+        assert_eq!(actual, "Nu");
+    })
+}
+
+#[test]
+fn downcases() {
+    Playground::setup("plugin_str_test_4", |dirs, sandbox| {
         sandbox.with_files(vec![FileWithContent(
             "sample.toml",
             r#"
@@ -55,7 +95,7 @@ fn downcases() {
 
 #[test]
 fn upcases() {
-    Playground::setup("plugin_str_test_3", |dirs, sandbox| {
+    Playground::setup("plugin_str_test_5", |dirs, sandbox| {
         sandbox.with_files(vec![FileWithContent(
             "sample.toml",
             r#"
@@ -93,7 +133,7 @@ fn converts_to_int() {
 
 #[test]
 fn replaces() {
-    Playground::setup("plugin_str_test_4", |dirs, sandbox| {
+    Playground::setup("plugin_str_test_5", |dirs, sandbox| {
         sandbox.with_files(vec![FileWithContent(
             "sample.toml",
             r#"
@@ -118,7 +158,7 @@ fn replaces() {
 
 #[test]
 fn find_and_replaces() {
-    Playground::setup("plugin_str_test_5", |dirs, sandbox| {
+    Playground::setup("plugin_str_test_6", |dirs, sandbox| {
         sandbox.with_files(vec![FileWithContent(
             "sample.toml",
             r#"
@@ -143,7 +183,7 @@ fn find_and_replaces() {
 
 #[test]
 fn find_and_replaces_without_passing_field() {
-    Playground::setup("plugin_str_test_6", |dirs, sandbox| {
+    Playground::setup("plugin_str_test_7", |dirs, sandbox| {
         sandbox.with_files(vec![FileWithContent(
             "sample.toml",
             r#"