gson-comments/gson/src/test/java/com/google/gson/functional/NumberLimitsTest.java

229 lines
9.1 KiB
Java

package com.google.gson.functional;
import static com.google.common.truth.Truth.assertThat;
import static org.junit.Assert.assertThrows;
import com.google.gson.Gson;
import com.google.gson.JsonParseException;
import com.google.gson.JsonPrimitive;
import com.google.gson.JsonSyntaxException;
import com.google.gson.ToNumberPolicy;
import com.google.gson.ToNumberStrategy;
import com.google.gson.TypeAdapter;
import com.google.gson.internal.LazilyParsedNumber;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
import com.google.gson.stream.MalformedJsonException;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.StringReader;
import java.math.BigDecimal;
import java.math.BigInteger;
import org.junit.Test;
public class NumberLimitsTest {
private static final int MAX_LENGTH = 10_000;
private static JsonReader jsonReader(String json) {
return new JsonReader(new StringReader(json));
}
/**
* Tests how {@link JsonReader} behaves for large numbers.
*
* <p>Currently {@link JsonReader} itself does not enforce any limits. The reasons for this are:
*
* <ul>
* <li>Methods such as {@link JsonReader#nextDouble()} seem to have no problem parsing extremely
* large or small numbers (it rounds to 0 or Infinity) (to be verified?; if it had
* performance problems with certain numbers, then it would affect other parts of Gson which
* parse as float or double as well)
* <li>Enforcing limits only when a JSON number is encountered would be ineffective when users
* want to consume a JSON number as string using {@link JsonReader#nextString()} unless they
* explicitly call {@link JsonReader#peek()} and check if the value is a JSON number.
* Otherwise the limits could be circumvented because {@link JsonReader#nextString()} reads
* both strings and numbers, and for JSON strings no restrictions are enforced.
* </ul>
*/
@Test
public void testJsonReader() throws IOException {
JsonReader reader = jsonReader("1".repeat(1000));
assertThat(reader.peek()).isEqualTo(JsonToken.NUMBER);
assertThat(reader.nextString()).isEqualTo("1".repeat(1000));
JsonReader reader2 = jsonReader("1".repeat(MAX_LENGTH + 1));
// Currently JsonReader does not recognize large JSON numbers as numbers but treats them
// as unquoted string
MalformedJsonException e = assertThrows(MalformedJsonException.class, () -> reader2.peek());
assertThat(e)
.hasMessageThat()
.startsWith("Use JsonReader.setStrictness(Strictness.LENIENT) to accept malformed JSON");
reader = jsonReader("1e9999");
assertThat(reader.peek()).isEqualTo(JsonToken.NUMBER);
assertThat(reader.nextString()).isEqualTo("1e9999");
reader = jsonReader("1e+9999");
assertThat(reader.peek()).isEqualTo(JsonToken.NUMBER);
assertThat(reader.nextString()).isEqualTo("1e+9999");
reader = jsonReader("1e10000");
assertThat(reader.peek()).isEqualTo(JsonToken.NUMBER);
assertThat(reader.nextString()).isEqualTo("1e10000");
reader = jsonReader("1e00001");
assertThat(reader.peek()).isEqualTo(JsonToken.NUMBER);
assertThat(reader.nextString()).isEqualTo("1e00001");
}
@Test
public void testJsonPrimitive() {
assertThat(new JsonPrimitive("1".repeat(MAX_LENGTH)).getAsBigDecimal())
.isEqualTo(new BigDecimal("1".repeat(MAX_LENGTH)));
assertThat(new JsonPrimitive("1e9999").getAsBigDecimal()).isEqualTo(new BigDecimal("1e9999"));
assertThat(new JsonPrimitive("1e-9999").getAsBigDecimal()).isEqualTo(new BigDecimal("1e-9999"));
NumberFormatException e =
assertThrows(
NumberFormatException.class,
() -> new JsonPrimitive("1".repeat(MAX_LENGTH + 1)).getAsBigDecimal());
assertThat(e)
.hasMessageThat()
.isEqualTo("Number string too large: 111111111111111111111111111111...");
e =
assertThrows(
NumberFormatException.class, () -> new JsonPrimitive("1e10000").getAsBigDecimal());
assertThat(e).hasMessageThat().isEqualTo("Number has unsupported scale: 1e10000");
e =
assertThrows(
NumberFormatException.class, () -> new JsonPrimitive("1e-10000").getAsBigDecimal());
assertThat(e).hasMessageThat().isEqualTo("Number has unsupported scale: 1e-10000");
assertThat(new JsonPrimitive("1".repeat(MAX_LENGTH)).getAsBigInteger())
.isEqualTo(new BigInteger("1".repeat(MAX_LENGTH)));
e =
assertThrows(
NumberFormatException.class,
() -> new JsonPrimitive("1".repeat(MAX_LENGTH + 1)).getAsBigInteger());
assertThat(e)
.hasMessageThat()
.isEqualTo("Number string too large: 111111111111111111111111111111...");
}
@Test
public void testToNumberPolicy() throws IOException {
ToNumberStrategy strategy = ToNumberPolicy.BIG_DECIMAL;
assertThat(strategy.readNumber(jsonReader("\"" + "1".repeat(MAX_LENGTH) + "\"")))
.isEqualTo(new BigDecimal("1".repeat(MAX_LENGTH)));
assertThat(strategy.readNumber(jsonReader("1e9999"))).isEqualTo(new BigDecimal("1e9999"));
JsonParseException e =
assertThrows(
JsonParseException.class,
() -> strategy.readNumber(jsonReader("\"" + "1".repeat(MAX_LENGTH + 1) + "\"")));
assertThat(e)
.hasMessageThat()
.isEqualTo("Cannot parse " + "1".repeat(MAX_LENGTH + 1) + "; at path $");
assertThat(e)
.hasCauseThat()
.hasMessageThat()
.isEqualTo("Number string too large: 111111111111111111111111111111...");
e =
assertThrows(
JsonParseException.class, () -> strategy.readNumber(jsonReader("\"1e10000\"")));
assertThat(e).hasMessageThat().isEqualTo("Cannot parse 1e10000; at path $");
assertThat(e)
.hasCauseThat()
.hasMessageThat()
.isEqualTo("Number has unsupported scale: 1e10000");
}
@Test
public void testLazilyParsedNumber() throws IOException {
assertThat(new LazilyParsedNumber("1".repeat(MAX_LENGTH)).intValue())
.isEqualTo(new BigDecimal("1".repeat(MAX_LENGTH)).intValue());
assertThat(new LazilyParsedNumber("1e9999").intValue())
.isEqualTo(new BigDecimal("1e9999").intValue());
NumberFormatException e =
assertThrows(
NumberFormatException.class,
() -> new LazilyParsedNumber("1".repeat(MAX_LENGTH + 1)).intValue());
assertThat(e)
.hasMessageThat()
.isEqualTo("Number string too large: 111111111111111111111111111111...");
e =
assertThrows(
NumberFormatException.class, () -> new LazilyParsedNumber("1e10000").intValue());
assertThat(e).hasMessageThat().isEqualTo("Number has unsupported scale: 1e10000");
e =
assertThrows(
NumberFormatException.class, () -> new LazilyParsedNumber("1e10000").longValue());
assertThat(e).hasMessageThat().isEqualTo("Number has unsupported scale: 1e10000");
ObjectOutputStream objOut = new ObjectOutputStream(OutputStream.nullOutputStream());
// Number is serialized as BigDecimal; should also enforce limits during this conversion
e =
assertThrows(
NumberFormatException.class,
() -> objOut.writeObject(new LazilyParsedNumber("1e10000")));
assertThat(e).hasMessageThat().isEqualTo("Number has unsupported scale: 1e10000");
}
@Test
public void testBigDecimalAdapter() throws IOException {
TypeAdapter<BigDecimal> adapter = new Gson().getAdapter(BigDecimal.class);
assertThat(adapter.fromJson("\"" + "1".repeat(MAX_LENGTH) + "\""))
.isEqualTo(new BigDecimal("1".repeat(MAX_LENGTH)));
assertThat(adapter.fromJson("\"1e9999\"")).isEqualTo(new BigDecimal("1e9999"));
JsonSyntaxException e =
assertThrows(
JsonSyntaxException.class,
() -> adapter.fromJson("\"" + "1".repeat(MAX_LENGTH + 1) + "\""));
assertThat(e)
.hasMessageThat()
.isEqualTo("Failed parsing '" + "1".repeat(MAX_LENGTH + 1) + "' as BigDecimal; at path $");
assertThat(e)
.hasCauseThat()
.hasMessageThat()
.isEqualTo("Number string too large: 111111111111111111111111111111...");
e = assertThrows(JsonSyntaxException.class, () -> adapter.fromJson("\"1e10000\""));
assertThat(e).hasMessageThat().isEqualTo("Failed parsing '1e10000' as BigDecimal; at path $");
assertThat(e)
.hasCauseThat()
.hasMessageThat()
.isEqualTo("Number has unsupported scale: 1e10000");
}
@Test
public void testBigIntegerAdapter() throws IOException {
TypeAdapter<BigInteger> adapter = new Gson().getAdapter(BigInteger.class);
assertThat(adapter.fromJson("\"" + "1".repeat(MAX_LENGTH) + "\""))
.isEqualTo(new BigInteger("1".repeat(MAX_LENGTH)));
JsonSyntaxException e =
assertThrows(
JsonSyntaxException.class,
() -> adapter.fromJson("\"" + "1".repeat(MAX_LENGTH + 1) + "\""));
assertThat(e)
.hasMessageThat()
.isEqualTo("Failed parsing '" + "1".repeat(MAX_LENGTH + 1) + "' as BigInteger; at path $");
assertThat(e)
.hasCauseThat()
.hasMessageThat()
.isEqualTo("Number string too large: 111111111111111111111111111111...");
}
}