improved error messages for wrongly provided dimensions

Author: kaifox

src/main/java/org/tensorics/gson/adapters/TensorbackedGsonAdapter.java

@@ -1,9 +1,7 @@
 package org.tensorics.gson.adapters;
 
 import com.google.common.annotations.VisibleForTesting;
-import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
-import com.google.common.collect.Lists;
 import com.google.gson.Gson;
 import com.google.gson.TypeAdapter;
 import com.google.gson.reflect.TypeToken;
@@ -14,7 +12,6 @@
 import org.tensorics.core.tensor.operations.TensorInternals;
 import org.tensorics.core.tensorbacked.Tensorbacked;
 import org.tensorics.core.tensorbacked.TensorbackedInternals;
-import org.tensorics.core.tensorbacked.Tensorbackeds;
 
 import java.io.IOException;
 import java.util.List;
@@ -37,7 +34,7 @@ public void write(JsonWriter out, TB value) throws IOException {
         /*XXX: The context of the tensor will currently NOT be serialized! */
 
         List<Class<?>> dimensions = TensorbackedInternals.dimensionListFrom(tensorbackedClass);
-        Object nested = nested(value.tensor(), dimensions);
+        Object nested = nestmap(value.tensor(), dimensions);
         if (nested instanceof Map) {
             TypeAdapter<Map<?, ?>> adapter = context.getAdapter(new TypeToken<Map<?, ?>>() {
             });
@@ -50,9 +47,12 @@ public void write(JsonWriter out, TB value) throws IOException {
     }
 
     @VisibleForTesting
-    static Object nested(Tensor<?> tensor, List<Class<?>> dimensions) {
-        if (Tensorics.dimensionsOf(tensor).size() != dimensions.size()) {
-            throw new IllegalArgumentException("Tensor dimension and provided dimension do not match!");
+    static Object nestmap(Tensor<?> tensor, List<Class<?>> dimensions) {
+        int tensorDimensionality = Tensorics.dimensionsOf(tensor).size();
+        if (tensorDimensionality != dimensions.size()) {
+            throw new IllegalArgumentException("Tensor dimensionality (" + tensorDimensionality +
+                    ") and number of provided dimensions (" + dimensions.size() + ": " + dimensions +
+                    ") do not match!");
         }
 
         if (dimensions.isEmpty()) {
@@ -63,7 +63,7 @@ static Object nested(Tensor<?> tensor, List<Class<?>> dimensions) {
         Tensor<? extends Map<?, ?>> mappedOut = TensorInternals.mapOut(tensor).inDirectionOf(dimension);
 
         List<Class<?>> remainingDimensions = dimensions.subList(0, dimensions.size() - 1);
-        return nested(mappedOut, remainingDimensions);
+        return nestmap(mappedOut, remainingDimensions);
     }
 
     @Override

src/test/java/org/tensorics/gson/adapters/NestingTest.java

@@ -5,27 +5,27 @@
 import org.assertj.core.api.Assertions;
 import org.junit.Test;
 import org.tensorics.core.lang.Tensorics;
-import org.tensorics.core.tensor.ImmutableScalar;
 import org.tensorics.core.tensor.Scalar;
 import org.tensorics.core.tensor.Tensor;
 import org.tensorics.core.tensorbacked.AbstractTensorbacked;
 import org.tensorics.core.tensorbacked.TensorbackedInternals;
 import org.tensorics.core.tensorbacked.annotation.Dimensions;
 
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.tensorics.core.lang.Tensorics.at;
 
 public class NestingTest {
 
     @Test
-    public void mapoutTensorWorks() {
+    public void nestmapTensorWorks() {
         AnInheritedTensorbacked val = Tensorics.builderFor(AnInheritedTensorbacked.class)//
                 .put(at("A", 1), 0.11)//
                 .put(at("B", 1), 0.21)
                 .put(at("A", 2), 0.12)//
                 .put(at("B", 2), 0.22)
                 .build();
 
-        Object nested = TensorbackedGsonAdapter.nested(val.tensor(), TensorbackedInternals.dimensionListFrom(AnInheritedTensorbacked.class));
+        Object nested = TensorbackedGsonAdapter.nestmap(val.tensor(), TensorbackedInternals.dimensionListFrom(AnInheritedTensorbacked.class));
 
         Assertions.assertThat(nested).isEqualTo(ImmutableMap.of(
                 "A", ImmutableMap.of(1, 0.11, 2, 0.12), //
@@ -35,27 +35,34 @@ public void mapoutTensorWorks() {
 
 
     @Test
-    public void mapoutScalarIsPlain() {
+    public void nestmapScalarIsPlain() {
         Scalar<Double> scalar = Tensorics.scalarOf(0.33);
 
-        Object nested = TensorbackedGsonAdapter.nested(scalar, ImmutableList.of());
+        Object nested = TensorbackedGsonAdapter.nestmap(scalar, ImmutableList.of());
         Assertions.assertThat(nested).isEqualTo(0.33);
     }
 
     @Dimensions({String.class, Integer.class})
     public static class AnInheritedTensorbacked extends AbstractTensorbacked<Double> {
-
         public AnInheritedTensorbacked(Tensor<Double> tensor) {
             super(tensor);
         }
-
     }
 
+    /* XXX Is this the correct behaviour? */
     @Test
-    public void mapoutEmptyTensorIsNull() {
+    public void nestmapEmptyTensorIsNull() {
         Tensor<Object> empty = Tensorics.builder(String.class, Integer.class).build();
-        Object nested = TensorbackedGsonAdapter.nested(empty, ImmutableList.of(String.class, Integer.class));
+        Object nested = TensorbackedGsonAdapter.nestmap(empty, ImmutableList.of(String.class, Integer.class));
         Assertions.assertThat(nested).isNull();
     }
 
+    @Test
+    public void nestmapWrongDimensionAmountThrows() {
+        Tensor<Object> empty = Tensorics.builder(String.class, Integer.class).build();
+        assertThatThrownBy(() -> TensorbackedGsonAdapter.nestmap(empty, ImmutableList.of(Integer.class)))//
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessageContaining("do not match!");
+    }
+
 }