BugFix BigDecimal.setScale with less than 1

bastie · Dec 11, 2023 · 396d450 · 396d450
1 parent ee602d8
commit 396d450
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Showing 3 changed files with 28 additions and 3 deletions.
diff --git a/README.md b/README.md
@@ -54,7 +54,7 @@ Check out these projects and learn how to use JavApi⁴Swift.
 
 * [ASCII-Data](https://github.com/bastie/ASCII-Data2JavApi.git) is a library to display tables and graphs on command line as ASCII or ANSI.
 
-### 0.7.3
+### 0.7.4
 
 * [LStXML2Code](https://github.com/bastie/LStXML2Code) is a library and CLI to generate source code for German income tax calculation based on Federal Ministry of Finance provided XML Pseudocode.
 

diff --git a/Sources/JavApi/math/BigDecimal+Java.swift b/Sources/JavApi/math/BigDecimal+Java.swift
@@ -18,8 +18,21 @@ extension java.math.BigDecimal {
     var doubleValue = (self as NSDecimalNumber).doubleValue
     switch roundingMode {
     case java.math.BigDecimal.ROUND_DOWN :
-      let string = String(format: "%.\(newScale)f" ,doubleValue)
-      result = java.math.BigDecimal.valueOf(string)!
+      var down = ""
+      if newScale > 0 {
+        down = String(format: "%.\(newScale)f" ,doubleValue)
+      }
+      else if newScale == 0 {
+        down = String(format:"%\(newScale)d",Int(doubleValue))
+      }
+      else {
+        let plusScale = newScale * -1
+        var computedFactor = 10
+        for _ in 1..<plusScale { computedFactor *= 10 }
+        doubleValue = Double( (Int(doubleValue) / computedFactor) * computedFactor )
+        down = String(format: "%\(newScale)f" ,doubleValue)
+      }
+      result = java.math.BigDecimal.valueOf(down)!
     case java.math.BigDecimal.ROUND_UP :
       let factor = switch newScale {
       case 0 : {return Double(1)}

diff --git a/Tests/JavApiTests/JavApi_math_BigDecimal.swift b/Tests/JavApiTests/JavApi_math_BigDecimal.swift
@@ -44,5 +44,17 @@ final class JavApi_math_BigDecimal_Tests: XCTestCase {
 
     XCTAssertEqual(downZero, 3)
     XCTAssertEqual(upZero, 4)
+
+    // scale 0 second test
+    let toRoundWithZero = java.math.BigDecimal (1103802.8199999998);
+    let roundOne = toRoundWithZero.setScale (1, java.math.BigDecimal.ROUND_DOWN);
+    let roundZero = toRoundWithZero.setScale (0, java.math.BigDecimal.ROUND_DOWN);
+    let roundMinusOne = toRoundWithZero.setScale (-1, java.math.BigDecimal.ROUND_DOWN);
+
+    XCTAssertEqual(roundOne, java.math.BigDecimal.valueOf("1103802.8")!)
+    XCTAssertEqual(roundZero, java.math.BigDecimal.valueOf("1103802")!)
+    XCTAssertEqual(roundMinusOne, java.math.BigDecimal.valueOf("1.10380E+6")!)
+
+
   }
 }