Improve lots of things

In particular:
 + make output more sane and less all over the place
 + just ignore original exception, the shrunk one is the only one which really
   matters
 + fit into the jUnit framework more (so now @Before, @After and stuff work)

4 files changed, 252 insertions, 129 deletions

diff --git a/src/main/java/au/id/zancanaro/PropertyTestError.java b/src/main/java/au/id/zancanaro/PropertyTestError.java
new file mode 100644
index 0000000..afd614b
--- /dev/null
+++ b/src/main/java/au/id/zancanaro/PropertyTestError.java
@@ -0,0 +1,45 @@
+package au.id.zancanaro;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Iterator;
+
+public class PropertyTestError extends AssertionError {
+    public PropertyTestError(String methodName, long seed, ShrinkResult shrunk) {
+        super(String.format("%s(%s)\n\tSeed: %s\n%s",
+                methodName, join(", ", shrunk.args),
+                seed,
+                shrunk.thrown.getMessage()));
+        initCause(shrunk.thrown);
+    }
+
+
+    public static String join(String delimiter, Object... params) {
+        return join(delimiter, Arrays.asList(params));
+    }
+
+    public static String join(String delimiter, Collection<Object> values) {
+        StringBuilder sb = new StringBuilder();
+        Iterator<Object> iter = values.iterator();
+        while (iter.hasNext()) {
+            Object next = iter.next();
+            sb.append(stringValueOf(next));
+            if (iter.hasNext()) {
+                sb.append(delimiter);
+            }
+        }
+        return sb.toString();
+    }
+
+    private static String stringValueOf(Object next) {
+        if (next instanceof String) {
+            return '"' + ((String) next).replace("\"", "\\\"") + '"';
+        } else {
+            try {
+                return String.valueOf(next);
+            } catch (Throwable e) {
+                return "[toString failed]";
+            }
+        }
+    }
+}
diff --git a/src/main/java/au/id/zancanaro/PropertyTestRunner.java b/src/main/java/au/id/zancanaro/PropertyTestRunner.java
index 8df9b2a..b3563ff 100644
--- a/src/main/java/au/id/zancanaro/PropertyTestRunner.java
+++ b/src/main/java/au/id/zancanaro/PropertyTestRunner.java
@@ -3,127 +3,204 @@ package au.id.zancanaro;
 import au.id.zancanaro.annotations.Property;
 import au.id.zancanaro.annotations.Seed;
 import org.junit.AssumptionViolatedException;
-import org.junit.Ignore;
-import org.junit.runner.Description;
-import org.junit.runner.notification.Failure;
-import org.junit.runner.notification.RunNotifier;
-import org.junit.runners.ParentRunner;
+import org.junit.runners.BlockJUnit4ClassRunner;
 import org.junit.runners.model.FrameworkMethod;
 import org.junit.runners.model.InitializationError;
+import org.junit.runners.model.Statement;
+import org.junit.runners.model.TestClass;
 
-import java.lang.annotation.Annotation;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
-import java.lang.reflect.Type;
+import java.lang.reflect.*;
 import java.util.*;
 
-public class PropertyTestRunner extends ParentRunner<FrameworkMethod> {
 
-    private final Class<?> classUnderTest;
+public class PropertyTestRunner extends BlockJUnit4ClassRunner {
+    private final Map<Type, Generator<Object>> generators = new HashMap<>();
 
-    public PropertyTestRunner(Class<?> classUnderTest) throws InitializationError{
-        super(classUnderTest);
-        this.classUnderTest = classUnderTest;
+    public PropertyTestRunner(Class<?> klass) throws InitializationError {
+        super(klass);
     }
 
     @Override
-    protected boolean isIgnored(FrameworkMethod child) {
-        return child.getAnnotation(Ignore.class) != null;
+    protected void collectInitializationErrors(List<Throwable> errors) {
+        super.collectInitializationErrors(errors);
+        validateGeneratorFields(errors);
     }
 
-    @Override
-    protected List<FrameworkMethod> getChildren() {
-        List<FrameworkMethod> result = new ArrayList<>();
-        for (Method method : classUnderTest.getDeclaredMethods()) {
-            if (method.isAnnotationPresent(Property.class)
-                    && !method.isAnnotationPresent(Ignore.class)) {
-                result.add(new FrameworkMethod(method));
+    private void validateGeneratorFields(List<Throwable> errors) {
+        Field[] fields = getTestClass().getJavaClass().getDeclaredFields();
+
+        for (Field field : fields) {
+            Type type = field.getGenericType();
+            if (!(type instanceof ParameterizedType)) {
+                continue;
+            }
+            ParameterizedType ptype = (ParameterizedType) type;
+            if (!(ptype.getRawType() instanceof Class)) {
+                continue;
+            }
+            Class<?> c = (Class) ptype.getRawType();
+            if (c != Generator.class) {
+                continue;
+            }
+            if (!Modifier.isStatic(field.getModifiers())) {
+                errors.add(new Error("Generator field " + field.getName() + " must be static"));
+            }
+            if (!Modifier.isPublic(field.getModifiers())) {
+                errors.add(new Error("Generator field " + field.getName() + " must be public"));
             }
         }
-        return result;
     }
 
-    @Override
-    protected Description describeChild(FrameworkMethod child) {
-        return Description.createTestDescription(classUnderTest, child.getName());
+    private static final Map<Type, Type> rawTypes;
+
+    static {
+        Map<Type, Type> types = new HashMap<>();
+        types.put(Double.class, Double.TYPE);
+        types.put(Float.class, Float.TYPE);
+        types.put(Long.class, Long.TYPE);
+        types.put(Integer.class, Integer.TYPE);
+        types.put(Short.class, Short.TYPE);
+        types.put(Byte.class, Byte.TYPE);
+        types.put(Character.class, Character.TYPE);
+        types.put(Boolean.class, Boolean.TYPE);
+        rawTypes = Collections.unmodifiableMap(types);
     }
 
-    @Override
-    protected void runChild(FrameworkMethod child, RunNotifier notifier) {
-        try {
-            Property details = child.getAnnotation(Property.class);
-            Description description = Description.createTestDescription(classUnderTest, child.getName());
-            boolean failed = false;
-            int assumptionsFailed = 0;
-
-            long seed = getSeed(child.getMethod());
-            Random random = new Random(seed);
-            int numRuns = details.runs();
-            for (int i = 0; i < numRuns && !failed; ++i) {
-                int size = details.size();
-                notifier.fireTestStarted(description);
-                Object obj;
-                try {
-                    obj = classUnderTest.getConstructor().newInstance();
-                } catch (Throwable ex) { // HACKY
-                    System.out.println(ex);
-                    return;
+    private Map<Type, Generator<Object>> computeGenerators() {
+        if (generators.isEmpty()) {
+            Field[] fields = getTestClass().getJavaClass().getDeclaredFields();
+
+            for (Field field : fields) {
+                Type type = field.getGenericType();
+                if (!(type instanceof ParameterizedType)) {
+                    continue;
+                }
+                ParameterizedType ptype = (ParameterizedType) type;
+                if (!(ptype.getRawType() instanceof Class)) {
+                    continue;
+                }
+                Class<?> c = (Class) ptype.getRawType();
+                if (c != Generator.class) {
+                    continue;
                 }
-                RoseTree<Object[]> generated = generateArgs(random, size,
-                        child.getMethod().getGenericParameterTypes(),
-                        child.getMethod().getParameterAnnotations());
                 try {
-                    child.getMethod().invoke(obj, generated.getValue());
-                } catch (InvocationTargetException ex) {
-                    if (ex.getTargetException() instanceof AssumptionViolatedException) {
-                        assumptionsFailed++;
-                        i--;
-                    } else {
-                        System.out.println("Test failed with seed: " + seed);
-                        System.out.println("Failing arguments: " + Arrays.asList(generated.getValue()));
-                        Object[] shrinkResult = shrink(child.getMethod(), obj, generated);
-                        if (shrinkResult == null) {
-                            System.out.println("Arguments could not be shrunk any further");
-                        } else {
-                            System.out.println("Arguments shrunk to: " + Arrays.asList(shrinkResult));
-                        }
-                        notifier.fireTestFailure(new Failure(description, ex.getTargetException()));
-                        failed = true;
+                    Type target = ptype.getActualTypeArguments()[0];
+                    @SuppressWarnings("unchecked")
+                    Generator<Object> generator = (Generator<Object>) field.get(null);
+                    generators.put(target, generator);
+                    if (rawTypes.containsKey(target)) {
+                        generators.put(rawTypes.get(target), generator);
                     }
                 } catch (IllegalAccessException ex) {
-                    notifier.fireTestFailure(new Failure(description, ex));
-                    failed = true;
+
                 }
             }
+        }
+        return generators;
+    }
 
-            if (assumptionsFailed > 0) {
-                System.out.println("Failed " + assumptionsFailed + " assumptions");
+    @Override
+    protected void validateConstructor(List<Throwable> errors) {
+        validateOnlyOneConstructor(errors);
+    }
+
+    @Override
+    protected void validateTestMethods(List<Throwable> errors) {
+        for (FrameworkMethod each : computeTestMethods()) {
+            if (each.getAnnotation(Property.class) != null) {
+                each.validatePublicVoid(false, errors);
+                each.validateNoTypeParametersOnArgs(errors);
+            } else {
+                each.validatePublicVoidNoArg(false, errors);
             }
-            notifier.fireTestFinished(description);
-        } catch (Throwable ex) {
-            ex.printStackTrace();
         }
     }
 
-    private long getSeed(Method method) {
-        Seed seed = method.getAnnotation(Seed.class);
-        if (seed == null) {
-            return System.currentTimeMillis();
-        } else {
-            return seed.value();
-        }
+    @Override
+    protected List<FrameworkMethod> computeTestMethods() {
+        List<FrameworkMethod> testMethods = new ArrayList<>(super.computeTestMethods());
+        List<FrameworkMethod> theoryMethods = getTestClass().getAnnotatedMethods(Property.class);
+        testMethods.removeAll(theoryMethods);
+        testMethods.addAll(theoryMethods);
+        return testMethods;
     }
 
-    private Object[] shrink(Method method, Object obj, RoseTree<Object[]> failed) {
-        Object[] smallest = failed.getValue();
-        Iterator<RoseTree<Object[]>> trees = failed.getChildren();
-        while (trees.hasNext()) {
-            RoseTree<Object[]> tree = trees.next();
-            try {
-                method.invoke(obj, tree.getValue());
-            } catch (InvocationTargetException ex) {
-                if (!(ex.getTargetException() instanceof AssumptionViolatedException)) {
-                    smallest = tree.getValue();
+    @Override
+    public Statement methodBlock(final FrameworkMethod method) {
+        return new GenerativeTester(method, getTestClass(), computeGenerators());
+    }
+
+    public static class GenerativeTester extends Statement {
+        private final FrameworkMethod testMethod;
+        private final TestClass testClass;
+        private final Map<Type, Generator<Object>> generators;
+
+        public GenerativeTester(FrameworkMethod testMethod, TestClass testClass, Map<Type, Generator<Object>> generators) {
+            this.testMethod = testMethod;
+            this.testClass = testClass;
+            this.generators = generators;
+        }
+
+        private long getSeed(Method method) {
+            Seed seed = method.getAnnotation(Seed.class);
+            if (seed == null) {
+                return System.currentTimeMillis();
+            } else {
+                return seed.value();
+            }
+        }
+
+        @Override
+        public void evaluate() throws Throwable {
+            Method method = testMethod.getMethod();
+            if (method.getParameterCount() == 0) {
+                runTest(new Object[0]);
+            } else {
+                @SuppressWarnings("unchecked")
+                Generator<Object>[] generators = (Generator<Object>[]) new Generator[method.getParameterCount()];
+                int index = 0;
+                for (Type type : method.getGenericParameterTypes()) {
+                    generators[index++] = this.generators.get(type);
+                }
+                Generator<Object[]> generator = Generator.tuple(generators);
+
+                long seed = getSeed(method);
+                Random random = new Random(seed);
+
+                Property property = testMethod.getAnnotation(Property.class);
+                int assumptionsViolated = 0;
+                int maxSize = property.maxSize();
+                int numTests = property.runs();
+                for (int i = 0; i < numTests; ++i) {
+                    int size = Math.min(i + 1, maxSize);
+                    RoseTree<Object[]> tree = generator.generate(random, size);
+                    try {
+                        runTest(tree.getValue());
+                        assumptionsViolated = 0;
+                    } catch (AssumptionViolatedException ex) {
+                        i--;
+                        if (assumptionsViolated++ == 50) {
+                            throw new Error("Violated 50 assumptions in a row: failing test");
+                        }
+                        ;
+                    } catch (Throwable ex) {
+                        throw new PropertyTestError(method.getName(), seed, shrink(tree, ex));
+                    }
+                }
+            }
+        }
+
+        private ShrinkResult shrink(RoseTree<Object[]> failed, Throwable originalEx) {
+            ShrinkResult smallest = new ShrinkResult(failed.getValue(), originalEx);
+            Iterator<RoseTree<Object[]>> trees = failed.getChildren();
+            while (trees.hasNext()) {
+                RoseTree<Object[]> tree = trees.next();
+                try {
+                    runTest(tree.getValue());
+                } catch (AssumptionViolatedException ex) {
+                    // ignore, because it's not useful
+                } catch (Throwable ex) {
+                    smallest = new ShrinkResult(tree.getValue(), ex);
                     Iterator<RoseTree<Object[]>> children = tree.getChildren();
                     if (children.hasNext()) {
                         trees = children;
@@ -131,49 +208,39 @@ public class PropertyTestRunner extends ParentRunner<FrameworkMethod> {
                         break;
                     }
                 }
-            } catch (IllegalAccessException ex) {
-                System.out.println(ex);
             }
+            return smallest;
         }
-        return smallest;
-    }
 
-    private <T> String printShrinkTree(RoseTree<T[]> generated) {
-        StringBuilder builder = new StringBuilder();
-        builder.append('(');
-        builder.append(Arrays.toString(generated.getValue()));
-        generated.getChildren().forEachRemaining((child) -> {
-            builder.append(' ');
-            builder.append(printShrinkTree(child));
-        });
-        builder.append(')');
-        return builder.toString();
-    }
+        public void runTest(final Object[] args) throws Throwable {
+            new BlockJUnit4ClassRunner(testClass.getJavaClass()) {
+                @Override
+                protected void collectInitializationErrors(
+                        List<Throwable> errors) {
+                    // do nothing
+                }
 
+                @Override
+                public Statement methodBlock(FrameworkMethod method) {
+                    return super.methodBlock(method);
+                }
 
-    private RoseTree<Object[]> generateArgs(Random random, int size, Type[] types, Annotation[][] annotations) {
-        Generator<?>[] generators = new Generator[types.length];
-        for (int i = 0; i < types.length; ++i) {
-//            generators[i] = getGeneratorFromAnnotations(annotations[i]);
-//            if (generators[i] == null) {
-                generators[i] = getGeneratorFromType(types[i]);
-//            }
-        }
-        @SuppressWarnings("unchecked")
-        Generator<Object>[] argsGenerators = (Generator<Object>[]) generators;
-        return Generator.tuple(argsGenerators).generate(random, size);
-    }
+                @Override
+                protected Statement methodInvoker(FrameworkMethod method, Object test) {
+                    return new Statement() {
+                        @Override
+                        public void evaluate() throws Throwable {
+                            method.invokeExplosively(test, args);
+                        }
+                    };
+                }
 
-    private Generator<?> getGeneratorFromType(Type type) {
-        if (type instanceof Class) {
-            Class<?> clazz = (Class<?>) type;
-            if (clazz.isPrimitive() && clazz == Integer.TYPE) {
-                return Generators.integer();
-            } else {
-                throw new RuntimeException("Unknown type for generator (atm only int is supported)");
-            }
-        } else {
-            throw new RuntimeException("Unknown type for generator (atm only int is supported)");
+                @Override
+                public Object createTest() throws Exception {
+                    return getTestClass().getOnlyConstructor().newInstance();
+                }
+            }.methodBlock(testMethod).evaluate();
         }
     }
-}
+
+}
\ No newline at end of file
diff --git a/src/main/java/au/id/zancanaro/ShrinkResult.java b/src/main/java/au/id/zancanaro/ShrinkResult.java
new file mode 100644
index 0000000..fb2f2d4
--- /dev/null
+++ b/src/main/java/au/id/zancanaro/ShrinkResult.java
@@ -0,0 +1,11 @@
+package au.id.zancanaro;
+
+class ShrinkResult {
+    public final Object[] args;
+    public final Throwable thrown;
+
+    public ShrinkResult(Object[] args, Throwable thrown) {
+        this.args = args;
+        this.thrown = thrown;
+    }
+}
diff --git a/src/main/java/au/id/zancanaro/annotations/Property.java b/src/main/java/au/id/zancanaro/annotations/Property.java
index cfe8e45..f750596 100644
--- a/src/main/java/au/id/zancanaro/annotations/Property.java
+++ b/src/main/java/au/id/zancanaro/annotations/Property.java
@@ -8,6 +8,6 @@ import java.lang.annotation.Target;
 @Target(ElementType.METHOD)
 @Retention(RetentionPolicy.RUNTIME)
 public @interface Property {
-    int size() default 100;
+    int maxSize() default 100;
     int runs() default 100;
 }