Fix up some static analysis warnings and improve @DataPoint detection

6 files changed, 54 insertions, 43 deletions

diff --git a/src/main/java/au/id/zancanaro/javacheck/Generator.java b/src/main/java/au/id/zancanaro/javacheck/Generator.java
index 4b9113c..c28d967 100644
--- a/src/main/java/au/id/zancanaro/javacheck/Generator.java
+++ b/src/main/java/au/id/zancanaro/javacheck/Generator.java
@@ -19,6 +19,7 @@ import java.util.function.Function;
  *
  * @param <T> The type generated by this generator.
  */
+@SuppressWarnings("unused")
 public interface Generator<T> {
     /**
      * Return a {@link RoseTree} containing a new random value of the required
@@ -115,9 +116,9 @@ public interface Generator<T> {
     /**
      * Produce a new generator relying on the value generated by this generator
      *
-     * Shrinking is a bit hard to predict under {@link #flatMap}, as it will
-     * first attempt to shrink this, resulting in the re-evaluation of action,
-     * and hence the re-generation of the subtree.
+     * Shrinking is a bit hard to predict under flatMap, as it will first
+     * attempt to shrink this, resulting in the re-evaluation of action, and
+     * hence the re-generation of the subtree.
      *
      * @param action A function to produce the new generator
      * @param <R>    The type of the returned generator
diff --git a/src/main/java/au/id/zancanaro/javacheck/Generators.java b/src/main/java/au/id/zancanaro/javacheck/Generators.java
index eab3eed..548bd29 100644
--- a/src/main/java/au/id/zancanaro/javacheck/Generators.java
+++ b/src/main/java/au/id/zancanaro/javacheck/Generators.java
@@ -7,6 +7,7 @@ import java.util.List;
 import java.util.function.Function;
 import java.util.function.Predicate;
 
+@SuppressWarnings("unused")
 public final class Generators {
     private Generators() {
     }
@@ -26,6 +27,12 @@ public final class Generators {
         };
     }
 
+    public static <T> Generator<T> noShrink(Generator<T> gen) {
+        return (random, size) -> new RoseTree<>(
+                gen.generate(random, size).getValue(),
+                Collections.emptyList());
+    }
+
     @SafeVarargs
     public static <T> Generator<T> oneOf(Generator<T>... gens) {
         return integer(0, gens.length).flatMap(index -> gens[index]);
@@ -91,8 +98,6 @@ public final class Generators {
         };
     }
 
-    ;
-
     public static <T> Generator<List<T>> listOf(Generator<T> gen) {
         return (random, size) -> {
             Generator<Integer> countGen = sized(s -> integer(0, s));
diff --git a/src/main/java/au/id/zancanaro/javacheck/Iterators.java b/src/main/java/au/id/zancanaro/javacheck/Iterators.java
index 33652b2..3f365eb 100644
--- a/src/main/java/au/id/zancanaro/javacheck/Iterators.java
+++ b/src/main/java/au/id/zancanaro/javacheck/Iterators.java
@@ -95,6 +95,7 @@ public final class Iterators {
 
     }
 
+    @SuppressWarnings("WeakerAccess")
     public static <T> EmptyIterator<T> emptyIterator() {
         return new EmptyIterator<>();
     }
diff --git a/src/main/java/au/id/zancanaro/javacheck/RoseTree.java b/src/main/java/au/id/zancanaro/javacheck/RoseTree.java
index 5a54d6f..c735b46 100644
--- a/src/main/java/au/id/zancanaro/javacheck/RoseTree.java
+++ b/src/main/java/au/id/zancanaro/javacheck/RoseTree.java
@@ -6,6 +6,7 @@ import java.util.*;
 import java.util.function.Function;
 import java.util.function.Predicate;
 
+@SuppressWarnings("unused")
 public class RoseTree<T> {
     private final T value;
     private final Iterable<RoseTree<T>> children;
@@ -49,14 +50,17 @@ public class RoseTree<T> {
                 ));
     }
 
-    public static <T, R> RoseTree<R> zip(Function<List<T>, R> fn, RoseTree<T>[] trees) {
-        @SuppressWarnings("unchecked")
-        List<T> heads = new ArrayList(trees.length);
+    private static <T> List<T> makeHeadList(RoseTree<T>[] trees) {
+        List<T> heads = new ArrayList<>(trees.length);
         for (RoseTree<T> tree : trees) {
             heads.add(tree.getValue());
         }
+        return heads;
+    }
+
+    public static <T, R> RoseTree<R> zip(Function<List<T>, R> fn, RoseTree<T>[] trees) {
         return new RoseTree<>(
-                fn.apply(heads),
+                fn.apply(makeHeadList(trees)),
                 () -> Iterators.mappingIterator(
                         roses -> RoseTree.zip(fn, roses),
                         RoseTree.permutations(trees)));
@@ -76,13 +80,8 @@ public class RoseTree<T> {
     }
 
     public static <T, R> RoseTree<R> shrink(Function<List<T>, R> fn, RoseTree<T>[] trees) {
-        @SuppressWarnings("unchecked")
-        List<T> heads = new ArrayList(trees.length);
-        for (RoseTree<T> tree : trees) {
-            heads.add(tree.getValue());
-        }
         return new RoseTree<>(
-                fn.apply(heads),
+                fn.apply(makeHeadList(trees)),
                 () -> Iterators.mappingIterator(
                         roses -> RoseTree.shrink(fn, roses),
                         RoseTree.removeEach(trees)));
diff --git a/src/main/java/au/id/zancanaro/javacheck/junit/Properties.java b/src/main/java/au/id/zancanaro/javacheck/junit/Properties.java
index 6ff0538..1e3f502 100644
--- a/src/main/java/au/id/zancanaro/javacheck/junit/Properties.java
+++ b/src/main/java/au/id/zancanaro/javacheck/junit/Properties.java
@@ -16,6 +16,7 @@ import org.junit.runners.model.TestClass;
 import java.lang.reflect.*;
 import java.util.*;
 
+@SuppressWarnings("WeakerAccess")
 public class Properties extends BlockJUnit4ClassRunner {
     private final Map<Type, Generator<?>> generators = new HashMap<>();
 
@@ -35,32 +36,36 @@ public class Properties extends BlockJUnit4ClassRunner {
         Field[] fields = getTestClass().getJavaClass().getDeclaredFields();
 
         for (Field field : fields) {
-            if (!field.isAnnotationPresent(DataSource.class)) {
-                continue;
-            }
-            Type type = field.getGenericType();
-            if (!(type instanceof ParameterizedType)) {
-                continue;
-            }
-            ParameterizedType parameterizedType = (ParameterizedType) type;
-            if (!(parameterizedType.getRawType() instanceof Class)) {
-                continue;
-            }
-            Class<?> c = (Class) parameterizedType.getRawType();
-            if (c != Generator.class) {
-                continue;
-            }
-            boolean error = false;
-            if (!Modifier.isStatic(field.getModifiers())) {
-                errors.add(new Error("Generator field " + field.getName() + " must be static"));
-                error = true;
-            }
-            if (!Modifier.isPublic(field.getModifiers())) {
-                errors.add(new Error("Generator field " + field.getName() + " must be public"));
-                error = true;
-            }
-            if (!error) {
-                result.add(parameterizedType.getActualTypeArguments()[0]);
+            if (field.isAnnotationPresent(DataSource.class)) {
+                boolean error = false;
+                if (!Modifier.isStatic(field.getModifiers())) {
+                    errors.add(new Error("@DataSource field " + field.getName() + " must be static"));
+                    error = true;
+                }
+                if (!Modifier.isPublic(field.getModifiers())) {
+                    errors.add(new Error("@DataSource field " + field.getName() + " must be public"));
+                    error = true;
+                }
+
+                Type type = field.getGenericType();
+                ParameterizedType parameterizedType;;
+                if (type instanceof ParameterizedType) {
+                    parameterizedType = (ParameterizedType) type;
+                    if (parameterizedType.getRawType() instanceof Class) {
+                        Class<?> c = (Class) parameterizedType.getRawType();
+                        if (c == Generator.class) {
+                            if (!error) {
+                                result.add(parameterizedType.getActualTypeArguments()[0]);
+                            }
+                        } else {
+                            errors.add(new Error("@DataSource fields must be of type Generator<T>"));
+                        }
+                    } else {
+                        errors.add(new Error("@DataSource fields must be of type Generator<T>"));
+                    }
+                } else {
+                    errors.add(new Error("@DataSource fields must be of type Generator<T>"));
+                }
             }
         }
         return result;
diff --git a/src/main/java/au/id/zancanaro/javacheck/junit/PropertyError.java b/src/main/java/au/id/zancanaro/javacheck/junit/PropertyError.java
index 2cd1325..44c071b 100644
--- a/src/main/java/au/id/zancanaro/javacheck/junit/PropertyError.java
+++ b/src/main/java/au/id/zancanaro/javacheck/junit/PropertyError.java
@@ -5,6 +5,7 @@ import au.id.zancanaro.javacheck.ShrinkResult;
 import java.util.Arrays;
 import java.util.Iterator;
 
+@SuppressWarnings("WeakerAccess")
 public class PropertyError extends AssertionError {
     public PropertyError(String methodName, long seed, ShrinkResult shrunk) {
         super(shrunk.thrown.getMessage() == null ?
@@ -18,8 +19,7 @@ public class PropertyError extends AssertionError {
         initCause(shrunk.thrown);
     }
 
-
-    public static String joinArgs(Object... params) {
+    private static String joinArgs(Object... params) {
         StringBuilder sb = new StringBuilder();
         Iterator<Object> iterator = Arrays.asList(params).iterator();
         while (iterator.hasNext()) {