Adding parse fix for power operator error on negative integers and de… (#3821)

* Adding parse fix for power operator error on negative integers and decimal

* Adding correct formatting

* Changed is negative check to follow conventions

* Adding tests

* Added fix for the negatives and added tests

* Removed comments

crates/nu-data/src/value.rs

@@ -1,6 +1,7 @@
 use crate::base::coerce_compare;
 use crate::base::shape::{Column, InlineShape};
 use crate::primitive::style_primitive;
+use bigdecimal::Signed;
 use chrono::{DateTime, NaiveDate, Utc};
 use nu_errors::ShellError;
 use nu_protocol::hir::Operator;
@@ -9,6 +10,7 @@ use nu_protocol::{Primitive, Type, UntaggedValue};
 use nu_source::{DebugDocBuilder, PrettyDebug, Span, Tagged};
 use nu_table::TextStyle;
 use num_bigint::BigInt;
+use num_bigint::ToBigInt;
 use num_traits::{ToPrimitive, Zero};
 use std::collections::HashMap;
 
@@ -171,10 +173,31 @@ pub fn compute_values(
                 }
                 Operator::Pow => {
                     let prim_u32 = ToPrimitive::to_u32(y);
+
+                    let sign = match x.is_negative() {
+                        true => -1,
+                        false => 1,
+                    };
+
+                    if !y.is_negative() {
                         match prim_u32 {
-                        Some(num) => Ok(UntaggedValue::Primitive(Primitive::Int(x.pow(num)))),
+                            Some(num) => Ok(UntaggedValue::Primitive(Primitive::Int(
+                                sign * (x.pow(num)),
+                            ))),
                             _ => Err((left.type_name(), right.type_name())),
                         }
+                    } else {
+                        let yp = bigdecimal::ToPrimitive::to_f64(y).unwrap_or(0.0);
+                        let xp = bigdecimal::ToPrimitive::to_f64(x).unwrap_or(0.0);
+
+                        let pow =
+                            bigdecimal::FromPrimitive::from_f64((sign as f64) * (xp.powf(yp)));
+
+                        match pow {
+                            Some(p) => Ok(UntaggedValue::Primitive(Primitive::Decimal(p))),
+                            _ => Err((left.type_name(), right.type_name())),
+                        }
+                    }
                 }
                 _ => Err((left.type_name(), right.type_name())),
             },
@@ -211,10 +234,29 @@ pub fn compute_values(
                 }
                 Operator::Pow => {
                     let prim_u32 = ToPrimitive::to_u32(y);
+
+                    let sign = match x.is_negative() {
+                        true => -1,
+                        false => 1,
+                    };
+
+                    if !y.is_negative() {
                         match prim_u32 {
-                        Some(num) => Ok(UntaggedValue::Primitive(Primitive::Int(x.pow(num)))),
+                            Some(num) => Ok(UntaggedValue::Primitive(Primitive::Int(
+                                sign * (x.pow(num)),
+                            ))),
                             _ => Err((left.type_name(), right.type_name())),
                         }
+                    } else {
+                        let yp = bigdecimal::ToPrimitive::to_f64(y).unwrap_or(0.0);
+                        let xp = bigdecimal::ToPrimitive::to_f64(x).unwrap_or(0.0);
+                        let pow =
+                            bigdecimal::FromPrimitive::from_f64((sign as f64) * (xp.powf(yp)));
+                        match pow {
+                            Some(p) => Ok(UntaggedValue::Primitive(Primitive::Decimal(p))),
+                            _ => Err((left.type_name(), right.type_name())),
+                        }
+                    }
                 }
                 _ => Err((left.type_name(), right.type_name())),
             },
@@ -251,10 +293,28 @@ pub fn compute_values(
                 }
                 Operator::Pow => {
                     let prim_u32 = ToPrimitive::to_u32(y);
+
+                    let sign = match x.is_negative() {
+                        true => -1,
+                        false => 1,
+                    };
+
+                    if !y.is_negative() {
                         match prim_u32 {
-                        Some(num) => Ok(UntaggedValue::Primitive(Primitive::BigInt(x.pow(num)))),
+                            Some(num) => Ok(UntaggedValue::Primitive(Primitive::BigInt(
+                                (sign.to_bigint().unwrap_or_default()) * x.pow(num),
+                            ))),
                             _ => Err((left.type_name(), right.type_name())),
                         }
+                    } else {
+                        let yp = bigdecimal::ToPrimitive::to_f64(y).unwrap_or(0.0);
+                        let xp = bigdecimal::ToPrimitive::to_f64(x).unwrap_or(0.0);
+                        let pow = bigdecimal::FromPrimitive::from_f64((sign as f64) * xp.powf(yp));
+                        match pow {
+                            Some(p) => Ok(UntaggedValue::Primitive(Primitive::Decimal(p))),
+                            _ => Err((left.type_name(), right.type_name())),
+                        }
+                    }
                 }
                 _ => Err((left.type_name(), right.type_name())),
             },
@@ -283,10 +343,31 @@ pub fn compute_values(
                 }
                 Operator::Pow => {
                     let prim_u32 = ToPrimitive::to_u32(y);
+
+                    let sign = match x.is_negative() {
+                        true => -1,
+                        false => 1,
+                    };
+
+                    if !y.is_negative() {
                         match prim_u32 {
-                        Some(num) => Ok(UntaggedValue::Primitive(Primitive::BigInt(x.pow(num)))),
+                            Some(num) => Ok(UntaggedValue::Primitive(Primitive::BigInt(
+                                (sign.to_bigint().unwrap_or_default()).pow(num),
+                            ))),
                             _ => Err((left.type_name(), right.type_name())),
                         }
+                    } else {
+                        let yp = bigdecimal::ToPrimitive::to_f64(y).unwrap_or(0.0);
+                        let xp = bigdecimal::ToPrimitive::to_f64(x).unwrap_or(0.0);
+
+                        let pow =
+                            bigdecimal::FromPrimitive::from_f64((sign as f64) * (xp.powf(yp)));
+
+                        match pow {
+                            Some(p) => Ok(UntaggedValue::Primitive(Primitive::Decimal(p))),
+                            _ => Err((left.type_name(), right.type_name())),
+                        }
+                    }
                 }
                 _ => Err((left.type_name(), right.type_name())),
             },
@@ -307,16 +388,22 @@ pub fn compute_values(
                         }
                         Ok(x % bigdecimal::BigDecimal::from(*y))
                     }
-                    // leaving this here for the hope that bigdecimal will one day support pow/powf/fpow
+
-                    // Operator::Pow => {
+                    Operator::Pow => {
-                    //     let xp = bigdecimal::ToPrimitive::to_f64(x).unwrap_or(0.0);
+                        let sign = match x.is_negative() {
-                    //     let yp = bigdecimal::ToPrimitive::to_f64(y).unwrap_or(0.0);
+                            true => -1,
-                    //     let pow = bigdecimal::FromPrimitive::from_f64(xp.powf(yp));
+                            false => 1,
-                    //     match pow {
+                        };
-                    //         Some(p) => Ok(p),
+
-                    //         None => Err((left.type_name(), right.type_name())),
+                        let yp = bigdecimal::ToPrimitive::to_f64(y).unwrap_or(0.0);
-                    //     }
+                        let xp = bigdecimal::ToPrimitive::to_f64(x).unwrap_or(0.0);
-                    // }
+                        let pow =
+                            bigdecimal::FromPrimitive::from_f64((sign as f64) * (xp.powf(yp)));
+                        match pow {
+                            Some(p) => Ok(p),
+                            None => Err((left.type_name(), right.type_name())),
+                        }
+                    }
                     _ => Err((left.type_name(), right.type_name())),
                 }?;
                 Ok(UntaggedValue::Primitive(Primitive::Decimal(result)))
@@ -338,11 +425,22 @@ pub fn compute_values(
                         }
                         Ok(bigdecimal::BigDecimal::from(*x) % y)
                     }
-                    // big decimal doesn't support pow yet
+
-                    // Operator::Pow => {
+                    Operator::Pow => {
-                    //     let yp = bigdecimal::ToPrimitive::to_u32(y).unwrap_or(0);
+                        let sign = match x.is_negative() {
-                    //     Ok(bigdecimal::BigDecimal::from(x.pow(yp)))
+                            true => -1,
-                    // }
+                            false => 1,
+                        };
+
+                        let yp = bigdecimal::ToPrimitive::to_f64(y).unwrap_or(0.0);
+                        let xp = bigdecimal::ToPrimitive::to_f64(x).unwrap_or(0.0);
+                        let pow =
+                            bigdecimal::FromPrimitive::from_f64((sign as f64) * (xp.powf(yp)));
+                        match pow {
+                            Some(p) => Ok(p),
+                            None => Err((left.type_name(), right.type_name())),
+                        }
+                    }
                     _ => Err((left.type_name(), right.type_name())),
                 }?;
                 Ok(UntaggedValue::Primitive(Primitive::Decimal(result)))
@@ -364,16 +462,22 @@ pub fn compute_values(
                         }
                         Ok(x % bigdecimal::BigDecimal::from(y.clone()))
                     }
-                    // leaving this here for the hope that bigdecimal will one day support pow/powf/fpow
+
-                    // Operator::Pow => {
+                    Operator::Pow => {
-                    //     let xp = bigdecimal::ToPrimitive::to_f64(x).unwrap_or(0.0);
+                        let sign = match x.is_negative() {
-                    //     let yp = bigdecimal::ToPrimitive::to_f64(y).unwrap_or(0.0);
+                            true => -1,
-                    //     let pow = bigdecimal::FromPrimitive::from_f64(xp.powf(yp));
+                            false => 1,
-                    //     match pow {
+                        };
-                    //         Some(p) => Ok(p),
+
-                    //         None => Err((left.type_name(), right.type_name())),
+                        let yp = bigdecimal::ToPrimitive::to_f64(y).unwrap_or(0.0);
-                    //     }
+                        let xp = bigdecimal::ToPrimitive::to_f64(x).unwrap_or(0.0);
-                    // }
+                        let pow =
+                            bigdecimal::FromPrimitive::from_f64((sign as f64) * (xp.powf(yp)));
+                        match pow {
+                            Some(p) => Ok(p),
+                            None => Err((left.type_name(), right.type_name())),
+                        }
+                    }
                     _ => Err((left.type_name(), right.type_name())),
                 }?;
                 Ok(UntaggedValue::Primitive(Primitive::Decimal(result)))
@@ -395,11 +499,22 @@ pub fn compute_values(
                         }
                         Ok(bigdecimal::BigDecimal::from(x.clone()) % y)
                     }
-                    // big decimal doesn't support pow yet
+
-                    // Operator::Pow => {
+                    Operator::Pow => {
-                    //     let yp = bigdecimal::ToPrimitive::to_u32(y).unwrap_or(0);
+                        let sign = match x.is_negative() {
-                    //     Ok(bigdecimal::BigDecimal::from(x.pow(yp)))
+                            true => -1,
-                    // }
+                            false => 1,
+                        };
+
+                        let yp = bigdecimal::ToPrimitive::to_f64(y).unwrap_or(0.0);
+                        let xp = bigdecimal::ToPrimitive::to_f64(x).unwrap_or(0.0);
+                        let pow =
+                            bigdecimal::FromPrimitive::from_f64((sign as f64) * (xp.powf(yp)));
+                        match pow {
+                            Some(p) => Ok(p),
+                            None => Err((left.type_name(), right.type_name())),
+                        }
+                    }
                     _ => Err((left.type_name(), right.type_name())),
                 }?;
                 Ok(UntaggedValue::Primitive(Primitive::Decimal(result)))
@@ -421,16 +536,22 @@ pub fn compute_values(
                         }
                         Ok(x % y)
                     }
-                    // big decimal doesn't support pow yet
+
-                    // Operator::Pow => {
+                    Operator::Pow => {
-                    //     let xp = bigdecimal::ToPrimitive::to_f64(x).unwrap_or(0.0);
+                        let sign = match x.is_negative() {
-                    //     let yp = bigdecimal::ToPrimitive::to_f64(y).unwrap_or(0.0);
+                            true => -1,
-                    //     let pow = bigdecimal::FromPrimitive::from_f64(xp.powf(yp));
+                            false => 1,
-                    //     match pow {
+                        };
-                    //         Some(p) => Ok(p),
+
-                    //         None => Err((left.type_name(), right.type_name())),
+                        let yp = bigdecimal::ToPrimitive::to_f64(y).unwrap_or(0.0);
-                    //     }
+                        let xp = bigdecimal::ToPrimitive::to_f64(x).unwrap_or(0.0);
-                    // }
+                        let pow =
+                            bigdecimal::FromPrimitive::from_f64((sign as f64) * (xp.powf(yp)));
+                        match pow {
+                            Some(p) => Ok(p),
+                            None => Err((left.type_name(), right.type_name())),
+                        }
+                    }
                     _ => Err((left.type_name(), right.type_name())),
                 }?;
                 Ok(UntaggedValue::Primitive(Primitive::Decimal(result)))
@@ -578,9 +699,11 @@ pub fn format_for_column<'a>(
 
 #[cfg(test)]
 mod tests {
-    use super::merge_values;
     use super::Date as d;
     use super::UntaggedValue as v;
+    use super::{compute_values, merge_values};
+    use nu_protocol::hir::Operator;
+    use nu_protocol::{Primitive, UntaggedValue};
     use nu_source::TaggedItem;
 
     use indexmap::indexmap;
@@ -609,4 +732,107 @@ mod tests {
             merge_values(&table_author_row, &other_table_author_row).unwrap()
         );
     }
+
+    #[test]
+    fn pow_operator_negatives_and_decimals() {
+        // test 2 ** 2
+        let result_one = compute_values(
+            Operator::Pow,
+            &UntaggedValue::Primitive(Primitive::Int(2)),
+            &UntaggedValue::Primitive(Primitive::Int(2)),
+        );
+
+        assert_eq!(
+            result_one.unwrap(),
+            UntaggedValue::Primitive(Primitive::Int(4))
+        );
+
+        // test 2 ** 2.0
+        let rhs_decimal = bigdecimal::FromPrimitive::from_f64(2.0).unwrap();
+
+        let result_two = compute_values(
+            Operator::Pow,
+            &UntaggedValue::Primitive(Primitive::Int(2)),
+            &UntaggedValue::Primitive(Primitive::Decimal(rhs_decimal)),
+        );
+
+        let should_equal_four_decimal = bigdecimal::FromPrimitive::from_f64(4.0).unwrap();
+
+        assert_eq!(
+            result_two.unwrap(),
+            UntaggedValue::Primitive(Primitive::Decimal(should_equal_four_decimal))
+        );
+
+        // test 2.0 ** 2.0
+        let rhs_decimal = bigdecimal::FromPrimitive::from_f64(2.0).unwrap();
+        let lhs_decimal = bigdecimal::FromPrimitive::from_f64(2.0).unwrap();
+        let should_equal_four_decimal = bigdecimal::FromPrimitive::from_f64(4.0).unwrap();
+
+        let result_three = compute_values(
+            Operator::Pow,
+            &UntaggedValue::Primitive(Primitive::Decimal(lhs_decimal)),
+            &UntaggedValue::Primitive(Primitive::Decimal(rhs_decimal)),
+        );
+
+        assert_eq!(
+            result_three.unwrap(),
+            UntaggedValue::Primitive(Primitive::Decimal(should_equal_four_decimal))
+        );
+
+        // test 2 ** -2
+        let result_four = compute_values(
+            Operator::Pow,
+            &UntaggedValue::Primitive(Primitive::Int(2)),
+            &UntaggedValue::Primitive(Primitive::Int(-2)),
+        );
+
+        let should_equal_zero_decimal = bigdecimal::FromPrimitive::from_f64(0.25).unwrap();
+
+        assert_eq!(
+            result_four.unwrap(),
+            UntaggedValue::Primitive(Primitive::Decimal(should_equal_zero_decimal))
+        );
+
+        // test -2 ** -2
+        let result_five = compute_values(
+            Operator::Pow,
+            &UntaggedValue::Primitive(Primitive::Int(-2)),
+            &UntaggedValue::Primitive(Primitive::Int(-2)),
+        );
+
+        let should_equal_neg_zero_decimal = bigdecimal::FromPrimitive::from_f64(-0.25).unwrap();
+
+        assert_eq!(
+            result_five.unwrap(),
+            UntaggedValue::Primitive(Primitive::Decimal(should_equal_neg_zero_decimal))
+        );
+
+        // test -2 ** 2
+        let result_six = compute_values(
+            Operator::Pow,
+            &UntaggedValue::Primitive(Primitive::Int(-2)),
+            &UntaggedValue::Primitive(Primitive::Int(2)),
+        );
+
+        assert_eq!(
+            result_six.unwrap(),
+            UntaggedValue::Primitive(Primitive::Int(-4))
+        );
+
+        // test -2.0 ** 2
+        let lhs_decimal = bigdecimal::FromPrimitive::from_f64(-2.0).unwrap();
+        let should_equal_neg_four_decimal = bigdecimal::FromPrimitive::from_f64(-4.0).unwrap();
+
+        let result_seven = compute_values(
+            Operator::Pow,
+            &UntaggedValue::Primitive(Primitive::Decimal(lhs_decimal)),
+            &UntaggedValue::Primitive(Primitive::Int(2)),
+        );
+
+        // Need to validate
+        assert_eq!(
+            result_seven.unwrap(),
+            UntaggedValue::Primitive(Primitive::Decimal(should_equal_neg_four_decimal))
+        );
+    }
 }