create financial/price_plus_tax function

Author: alirezasariri78

src/financial/mod.rs

@@ -0,0 +1,3 @@
+mod price_plus_tax;
+
+pub use price_plus_tax::price_plus_tax;

src/financial/price_plus_tax.rs

@@ -0,0 +1,16 @@
+pub fn price_plus_tax(price: f64, tax_rate: f64) -> f64{
+    price * (1 as f64 + tax_rate)
+}   
+
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_price_plus_tax() {
+        assert_eq!(131.775,price_plus_tax(125.50, 0.05));
+        assert_eq!( 125.0,price_plus_tax(100.0, 0.25));
+    }
+}

src/lib.rs

@@ -19,6 +19,7 @@ pub mod number_theory;
 pub mod searching;
 pub mod sorting;
 pub mod string;
+pub mod financial;
 
 #[cfg(test)]
 mod tests {