fix tests, adjust gh actions

.github/workflows/lint.yml

@@ -5,6 +5,7 @@ on:
   push:
     branches:
       - main
+    paths: [src/**]
   pull_request:
     branches:
       - main
@@ -13,6 +14,8 @@ jobs:
   linter:
     name: Java Linter
     runs-on: ubuntu-latest
+    permissions:
+      contents: write
 
     steps:
       - name: Checkout code

.github/workflows/maven.yml

@@ -9,18 +9,19 @@
 name: Java CI with Maven
 
 on:
+  paths: [src/**]
   push:
     branches: [ "main" ]
   pull_request:
     branches: [ "main" ]
 
 jobs:
   build:
-
     runs-on: ubuntu-latest
 
     steps:
     - uses: actions/checkout@v4
+
     - name: Set up JDK 17
       uses: actions/setup-java@v4
       with:

src/test/java/LA/ComplexNumberTest.java

@@ -3,6 +3,8 @@
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import java.util.ArrayList;
+import java.util.Optional;
+
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
@@ -259,7 +261,7 @@ void multiplicativeInverse_realNumber() {
       ComplexNumber z = ComplexNumber.rectangular(2, 0); // Complex number 2
       ComplexNumber result = z.multiplicativeInverse().orElseThrow();
 
-      assertEquals(ComplexNumber.rectangular(0.5, 0), result);
+      assertEquals(ComplexNumber.rectangular(0.5, -0.0), result);
     }
 
     @Test
@@ -275,7 +277,7 @@ void multiplicativeInverse_complexNumber() {
     void multiplicativeInverse_zero() {
       ComplexNumber z = ComplexNumber.rectangular(0, 0); // Complex number 0
 
-      assertThrows(IllegalArgumentException.class, z::multiplicativeInverse);
+      assertEquals(Optional.empty(), z.multiplicativeInverse());
     }
 
     @Test