feat(into): add into-bool command (#499)

* feat(into): add example of into-bool

* feat(into): add convert from int and float

* feat(into): add converting string to bool

* feat(into): add converting value in table

* fix(into): update error

* fix(into): update span for example

* chore(into): update signature description

* float comparison using epsilon

* Update bool.rs

Co-authored-by: JT <547158+jntrnr@users.noreply.github.com>

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

@@ -0,0 +1,183 @@
+use nu_engine::CallExt;
+use nu_protocol::{
+    ast::{Call, CellPath},
+    engine::{Command, EngineState, Stack},
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+};
+
+#[derive(Clone)]
+pub struct SubCommand;
+
+impl Command for SubCommand {
+    fn name(&self) -> &str {
+        "into bool"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("into bool")
+            .rest(
+                "rest",
+                SyntaxShape::CellPath,
+                "column paths to convert to boolean (for table input)",
+            )
+            .category(Category::Conversions)
+    }
+
+    fn usage(&self) -> &str {
+        "Convert value to boolean"
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
+        into_bool(engine_state, stack, call, input)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        let span = Span::test_data();
+        vec![
+            Example {
+                description: "Convert value to boolean in table",
+                example: "echo [[value]; ['false'] ['1'] [0] [1.0] [$true]] | into bool value",
+                result: Some(Value::List {
+                    vals: vec![
+                        Value::Record {
+                            cols: vec!["value".to_string()],
+                            vals: vec![Value::boolean(false, span)],
+                            span,
+                        },
+                        Value::Record {
+                            cols: vec!["value".to_string()],
+                            vals: vec![Value::boolean(true, span)],
+                            span,
+                        },
+                        Value::Record {
+                            cols: vec!["value".to_string()],
+                            vals: vec![Value::boolean(false, span)],
+                            span,
+                        },
+                        Value::Record {
+                            cols: vec!["value".to_string()],
+                            vals: vec![Value::boolean(true, span)],
+                            span,
+                        },
+                        Value::Record {
+                            cols: vec!["value".to_string()],
+                            vals: vec![Value::boolean(true, span)],
+                            span,
+                        },
+                    ],
+                    span,
+                }),
+            },
+            Example {
+                description: "Convert bool to boolean",
+                example: "$true | into bool",
+                result: Some(Value::boolean(true, span)),
+            },
+            Example {
+                description: "convert decimal to boolean",
+                example: "1 | into bool",
+                result: Some(Value::boolean(true, span)),
+            },
+            Example {
+                description: "convert decimal string to boolean",
+                example: "'0.0' | into bool",
+                result: Some(Value::boolean(false, span)),
+            },
+            Example {
+                description: "convert string to boolean",
+                example: "'true' | into bool",
+                result: Some(Value::boolean(true, span)),
+            },
+        ]
+    }
+}
+
+fn into_bool(
+    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 string_to_boolean(s: &str, span: Span) -> Result<bool, ShellError> {
+    match s.trim().to_lowercase().as_str() {
+        "true" => Ok(true),
+        "false" => Ok(false),
+        o => {
+            let val = o.parse::<f64>();
+            match val {
+                Ok(f) => Ok(f.abs() >= f64::EPSILON),
+                Err(_) => Err(ShellError::CantConvert(
+                    "boolean".to_string(),
+                    "string".to_string(),
+                    span,
+                )),
+            }
+        }
+    }
+}
+
+fn action(input: &Value, span: Span) -> Value {
+    match input {
+        Value::Bool { .. } => input.clone(),
+        Value::Int { val, .. } => Value::Bool {
+            val: *val != 0,
+            span,
+        },
+        Value::Float { val, .. } => Value::Bool {
+            val: val.abs() >= f64::EPSILON,
+            span,
+        },
+        Value::String { val, .. } => match string_to_boolean(val, span) {
+            Ok(val) => Value::Bool { val, span },
+            Err(error) => Value::Error { error },
+        },
+        _ => Value::Error {
+            error: ShellError::UnsupportedInput(
+                "'into bool' does not support this input".into(),
+                span,
+            ),
+        },
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_examples() {
+        use crate::test_examples;
+
+        test_examples(SubCommand {})
+    }
+}

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

@@ -1,4 +1,5 @@
 mod binary;
+mod bool;
 mod command;
 mod datetime;
 mod decimal;
@@ -6,6 +7,7 @@ mod filesize;
 mod int;
 mod string;
 
+pub use self::bool::SubCommand as IntoBool;
 pub use self::filesize::SubCommand as IntoFilesize;
 pub use binary::SubCommand as IntoBinary;
 pub use command::Into;

crates/nu-command/src/default_context.rs

@@ -219,6 +219,7 @@ pub fn create_default_context() -> EngineState {
         // Conversions
         bind_command! {
             Into,
+            IntoBool,
             IntoBinary,
             IntoDatetime,
             IntoDecimal,