Improve number strategy implementation (#1987)

* Fix GsonBuilder not copying number strategies from Gson

* Improve ToNumberPolicy exception messages

gson/src/main/java/com/google/gson/GsonBuilder.java

@@ -130,6 +130,8 @@ public final class GsonBuilder {
     this.timeStyle = gson.timeStyle;
     this.factories.addAll(gson.builderFactories);
     this.hierarchyFactories.addAll(gson.builderHierarchyFactories);
+    this.objectToNumberStrategy = gson.objectToNumberStrategy;
+    this.numberToNumberStrategy = gson.numberToNumberStrategy;
   }
 
   /**

gson/src/main/java/com/google/gson/ToNumberPolicy.java

@@ -71,11 +71,11 @@ public enum ToNumberPolicy implements ToNumberStrategy {
         try {
           Double d = Double.valueOf(value);
           if ((d.isInfinite() || d.isNaN()) && !in.isLenient()) {
-            throw new MalformedJsonException("JSON forbids NaN and infinities: " + d + in);
+            throw new MalformedJsonException("JSON forbids NaN and infinities: " + d + "; at path " + in.getPath());
           }
           return d;
         } catch (NumberFormatException doubleE) {
-          throw new JsonParseException("Cannot parse " + value, doubleE);
+          throw new JsonParseException("Cannot parse " + value + "; at path " + in.getPath(), doubleE);
         }
       }
     }
@@ -91,7 +91,7 @@ public enum ToNumberPolicy implements ToNumberStrategy {
       try {
         return new BigDecimal(value);
       } catch (NumberFormatException e) {
-        throw new JsonParseException("Cannot parse " + value, e);
+        throw new JsonParseException("Cannot parse " + value + "; at path " + in.getPath(), e);
       }
     }
   }

gson/src/main/java/com/google/gson/internal/bind/JsonTreeReader.java

@@ -283,7 +283,7 @@ public final class JsonTreeReader extends JsonReader {
   }
 
   @Override public String toString() {
-    return getClass().getSimpleName();
+    return getClass().getSimpleName() + locationString();
   }
 
   public void promoteNameToValue() throws IOException {

gson/src/test/java/com/google/gson/ToNumberPolicyTest.java

@@ -33,6 +33,12 @@ public class ToNumberPolicyTest extends TestCase {
       strategy.readNumber(fromString("1e400"));
       fail();
     } catch (MalformedJsonException expected) {
+      assertEquals("JSON forbids NaN and infinities: Infinity at line 1 column 6 path $", expected.getMessage());
+    }
+    try {
+      strategy.readNumber(fromString("\"not-a-number\""));
+      fail();
+    } catch (NumberFormatException expected) {
     }
   }
 
@@ -52,7 +58,15 @@ public class ToNumberPolicyTest extends TestCase {
       strategy.readNumber(fromString("1e400"));
       fail();
     } catch (MalformedJsonException expected) {
+      assertEquals("JSON forbids NaN and infinities: Infinity; at path $", expected.getMessage());
     }
+    try {
+      strategy.readNumber(fromString("\"not-a-number\""));
+      fail();
+    } catch (JsonParseException expected) {
+      assertEquals("Cannot parse not-a-number; at path $", expected.getMessage());
+    }
+
     assertEquals(Double.NaN, strategy.readNumber(fromStringLenient("NaN")));
     assertEquals(Double.POSITIVE_INFINITY, strategy.readNumber(fromStringLenient("Infinity")));
     assertEquals(Double.NEGATIVE_INFINITY, strategy.readNumber(fromStringLenient("-Infinity")));
@@ -60,16 +74,19 @@ public class ToNumberPolicyTest extends TestCase {
       strategy.readNumber(fromString("NaN"));
       fail();
     } catch (MalformedJsonException expected) {
+      assertEquals("Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $", expected.getMessage());
     }
     try {
       strategy.readNumber(fromString("Infinity"));
       fail();
     } catch (MalformedJsonException expected) {
+      assertEquals("Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $", expected.getMessage());
     }
     try {
       strategy.readNumber(fromString("-Infinity"));
       fail();
     } catch (MalformedJsonException expected) {
+      assertEquals("Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $", expected.getMessage());
     }
   }
 
@@ -78,6 +95,13 @@ public class ToNumberPolicyTest extends TestCase {
     assertEquals(new BigDecimal("10.1"), strategy.readNumber(fromString("10.1")));
     assertEquals(new BigDecimal("3.141592653589793238462643383279"), strategy.readNumber(fromString("3.141592653589793238462643383279")));
     assertEquals(new BigDecimal("1e400"), strategy.readNumber(fromString("1e400")));
+
+    try {
+      strategy.readNumber(fromString("\"not-a-number\""));
+      fail();
+    } catch (JsonParseException expected) {
+      assertEquals("Cannot parse not-a-number; at path $", expected.getMessage());
+    }
   }
 
   public void testNullsAreNeverExpected() throws IOException {