Rename random decimal to random float (#10320)

# Description
Similar to #9979

# User-Facing Changes
`random decimal` will now raise a warning and can be removed in an
upcoming release.

New command is named `random float`

# Tests + Formatting
Tests updated and improved.

crates/nu-command/src/default_context.rs

@@ -368,6 +368,7 @@ pub fn add_shell_command_context(mut engine_state: EngineState) -> EngineState {
             RandomChars,
             RandomDecimal,
             RandomDice,
+            RandomFloat,
             RandomInteger,
             RandomUuid,
         };

crates/nu-command/src/random/decimal.rs

@@ -24,7 +24,11 @@ impl Command for SubCommand {
     }
 
     fn usage(&self) -> &str {
-        "Generate a random decimal within a range [min..max]."
+        "deprecated: Generate a random float within a range [min..max]."
+    }
+
+    fn extra_usage(&self) -> &str {
+        "Use `random float` instead"
     }
 
     fn search_terms(&self) -> Vec<&str> {
@@ -38,28 +42,38 @@ impl Command for SubCommand {
         call: &Call,
         _input: PipelineData,
     ) -> Result<PipelineData, ShellError> {
+        nu_protocol::report_error_new(
+            engine_state,
+            &ShellError::GenericError(
+                "Deprecated command".into(),
+                "`random decimal` is deprecated and will be removed in 0.86.".into(),
+                Some(call.head),
+                Some("Use `random float instead".into()),
+                vec![],
+            ),
+        );
         decimal(engine_state, stack, call)
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![
             Example {
-                description: "Generate a default decimal value between 0 and 1",
+                description: "Generate a default float value between 0 and 1",
                 example: "random decimal",
                 result: None,
             },
             Example {
-                description: "Generate a random decimal less than or equal to 500",
+                description: "Generate a random float less than or equal to 500",
                 example: "random decimal ..500",
                 result: None,
             },
             Example {
-                description: "Generate a random decimal greater than or equal to 100000",
+                description: "Generate a random float greater than or equal to 100000",
                 example: "random decimal 100000..",
                 result: None,
             },
             Example {
-                description: "Generate a random decimal between 1.0 and 1.1",
+                description: "Generate a random float between 1.0 and 1.1",
                 example: "random decimal 1.0..1.1",
                 result: None,
             },

crates/nu-command/src/random/float.rs

@@ -0,0 +1,122 @@
+use nu_engine::CallExt;
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{
+    Category, Example, PipelineData, Range, ShellError, Signature, Span, SyntaxShape, Type, Value,
+};
+use rand::prelude::{thread_rng, Rng};
+use std::cmp::Ordering;
+
+#[derive(Clone)]
+pub struct SubCommand;
+
+impl Command for SubCommand {
+    fn name(&self) -> &str {
+        "random float"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("random float")
+            .input_output_types(vec![(Type::Nothing, Type::Float)])
+            .allow_variants_without_examples(true)
+            .optional("range", SyntaxShape::Range, "Range of values")
+            .category(Category::Random)
+    }
+
+    fn usage(&self) -> &str {
+        "Generate a random float within a range [min..max]."
+    }
+
+    fn search_terms(&self) -> Vec<&str> {
+        vec!["generate"]
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &Call,
+        _input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        float(engine_state, stack, call)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Generate a default float value between 0 and 1",
+                example: "random float",
+                result: None,
+            },
+            Example {
+                description: "Generate a random float less than or equal to 500",
+                example: "random float ..500",
+                result: None,
+            },
+            Example {
+                description: "Generate a random float greater than or equal to 100000",
+                example: "random float 100000..",
+                result: None,
+            },
+            Example {
+                description: "Generate a random float between 1.0 and 1.1",
+                example: "random float 1.0..1.1",
+                result: None,
+            },
+        ]
+    }
+}
+
+fn float(
+    engine_state: &EngineState,
+    stack: &mut Stack,
+    call: &Call,
+) -> Result<PipelineData, ShellError> {
+    let span = call.head;
+    let range: Option<Range> = call.opt(engine_state, stack, 0)?;
+
+    let (min, max) = if let Some(r) = range {
+        if r.is_end_inclusive() {
+            (r.from.as_float()?, r.to.as_float()?)
+        } else if r.to.as_float()? >= 1.0 {
+            (r.from.as_float()?, r.to.as_float()? - 1.0)
+        } else {
+            (0.0, 0.0)
+        }
+    } else {
+        (0.0, 1.0)
+    };
+
+    match min.partial_cmp(&max) {
+        Some(Ordering::Greater) => Err(ShellError::InvalidRange {
+            left_flank: min.to_string(),
+            right_flank: max.to_string(),
+            span,
+        }),
+        Some(Ordering::Equal) => Ok(PipelineData::Value(
+            Value::float(min, Span::new(64, 64)),
+            None,
+        )),
+        _ => {
+            let mut thread_rng = thread_rng();
+            let result: f64 = thread_rng.gen_range(min..max);
+
+            Ok(PipelineData::Value(
+                Value::float(result, Span::new(64, 64)),
+                None,
+            ))
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_examples() {
+        use crate::test_examples;
+
+        test_examples(SubCommand {})
+    }
+}

crates/nu-command/src/random/mod.rs

@@ -2,6 +2,7 @@ mod bool;
 mod chars;
 mod decimal;
 mod dice;
+mod float;
 mod integer;
 mod random_;
 mod uuid;
@@ -10,6 +11,7 @@ pub use self::bool::SubCommand as RandomBool;
 pub use self::chars::SubCommand as RandomChars;
 pub use self::decimal::SubCommand as RandomDecimal;
 pub use self::dice::SubCommand as RandomDice;
+pub use self::float::SubCommand as RandomFloat;
 pub use self::integer::SubCommand as RandomInteger;
 pub use self::uuid::SubCommand as RandomUuid;
 pub use random_::RandomCommand as Random;

crates/nu-command/tests/commands/random/float.rs

@@ -0,0 +1,26 @@
+use nu_test_support::nu;
+
+#[test]
+fn generates_a_float() {
+    let actual = nu!("random float 42..43");
+
+    // Attention: this relies on the string output
+    assert!(actual.out.starts_with("42") || actual.out.starts_with("43"));
+    let actual = nu!("random float 42..43 | describe");
+
+    assert_eq!(actual.out, "float")
+}
+
+#[test]
+fn generates_55() {
+    let actual = nu!("random float 55..55");
+
+    assert!(actual.out.contains("55"));
+}
+
+#[test]
+fn generates_0() {
+    let actual = nu!("random float ..<1");
+
+    assert!(actual.out.contains('0'));
+}

crates/nu-command/tests/commands/random/mod.rs

@@ -1,7 +1,7 @@
 mod bool;
 mod chars;
-mod decimal;
 mod dice;
+mod float;
 mod integer;
 #[cfg(feature = "uuid_crate")]
 mod uuid;