(v2.5.0) Add mixedCase() for upper/lower case randomization

Strings like `blah` can be turned into `bLAh`.

README.md

@@ -80,6 +80,7 @@ import static io.qala.datagen.RandomShortApi.*;
 | `length(4).with(spacesRight(2)).english()`               |                      | `"hF  "`
 | `length(10).with(prefix("BLAH")).numeric()`              |                      | `"BLAH453677"`
 | `between(1, 10).alphanumerics(4)`                        |                      | `["cvA", "mTMDj0", "N", ""]`
+|                                                          | `mixedCase("blah")`  | `"bLaH"`
 
 ## Nulls & Blanks
 

datagen/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <artifactId>qala-datagen-parent</artifactId>
         <groupId>io.qala.datagen</groupId>
-        <version>2.4.0</version>
+        <version>2.5.0</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
 

datagen/src/main/java/io/qala/datagen/RandomShortApi.java

@@ -175,6 +175,20 @@ public static String specialSymbols(int exactLength) {
     public static String specialSymbols(int min, int max) {
         return between(min, max).specialSymbols();
     }
+    /**
+     * Returns a string with upper/lower case changed in random places, e.g. {@code Blah -> bLaH}
+     *
+     * @param original string to change the case of its letters, can't be null
+     * @return a string with upper/lower case letters in random places
+     */
+    public static String mixedCase(String original) {
+        char[] result = original.toCharArray();
+        for (int i = 0; i < result.length; i++) {
+            char c = result[i];
+            result[i] = bool() ? Character.toUpperCase(c) : Character.toLowerCase(c);
+        }
+        return new String(result);
+    }
 
     /**
      * Returns an array of random booleans (true/false).

datagen/src/test/java/io/qala/datagen/RandomShortApiTest.java

@@ -13,8 +13,7 @@
 import static org.hamcrest.CoreMatchers.hasItem;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.core.IsNot.not;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.*;
 
 @DisplayName("Functional Randomizer")
 class RandomShortApiTest {
@@ -46,6 +45,16 @@ class RandomShortApiTest {
         assertFalse(sampleMultiple(asList(integer(), integer())).isEmpty());
     }
 
+    @Test void mixedCaseReturnsSameStringWithDifferentCases() {
+        String original = alphanumeric(200);
+        String mixed = mixedCase(original);
+        assertNotEquals(original, mixed);
+        assertEquals(original.toLowerCase(), mixed.toLowerCase());
+    }
+    @Test void emptyStringInMixedCaseIsEmptyString() {
+        assertEquals("", mixedCase(blankOr("")));
+    }
+
     private void assertOnlyOneIsNull(Object o1, Object o2) {
         if (o1 == null) assertNotNull(o2);
         if (o2 == null) assertNotNull(o1);

examples/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <artifactId>qala-datagen-parent</artifactId>
         <groupId>io.qala.datagen</groupId>
-        <version>2.4.0</version>
+        <version>2.5.0</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
 

java8types/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <artifactId>qala-datagen-parent</artifactId>
         <groupId>io.qala.datagen</groupId>
-        <version>2.4.0</version>
+        <version>2.5.0</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
 

junit5/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <artifactId>qala-datagen-parent</artifactId>
         <groupId>io.qala.datagen</groupId>
-        <version>2.4.0</version>
+        <version>2.5.0</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
 

pom.xml

@@ -7,7 +7,7 @@
     <groupId>io.qala.datagen</groupId>
     <artifactId>qala-datagen-parent</artifactId>
     <packaging>pom</packaging>
-    <version>2.4.0</version>
+    <version>2.5.0</version>
 
     <licenses>
         <license>