Merge pull request #1142 from HubSpot/limit-coerced-strings

limit coerced string length
HubSpot · Jan 8, 2024 · 05e6579 · 05e6579
2 parents f623369 + ed9170c
commit 05e6579
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diff --git a/src/main/java/com/hubspot/jinjava/el/TruthyTypeConverter.java b/src/main/java/com/hubspot/jinjava/el/TruthyTypeConverter.java
@@ -5,11 +5,14 @@
 import de.odysseus.el.misc.TypeConverterImpl;
 import java.math.BigDecimal;
 import java.math.BigInteger;
+import java.util.Collection;
 import java.util.EnumSet;
+import java.util.Iterator;
 import javax.el.ELException;
 
 public class TruthyTypeConverter extends TypeConverterImpl {
   private static final long serialVersionUID = 1L;
+  public static final int MAX_COLLECTION_STRING_LENGTH = 1_000_000;
 
   @Override
   protected Boolean coerceToBoolean(Object value) {
@@ -93,7 +96,44 @@ protected String coerceToString(Object value) {
     if (value instanceof DummyObject) {
       return "";
     }
-    return super.coerceToString(value);
+    if (value == null) {
+      return "";
+    }
+    if (value instanceof String) {
+      return (String) value;
+    }
+    if (value instanceof Enum<?>) {
+      return ((Enum<?>) value).name();
+    }
+
+    if (value instanceof Collection) {
+      return coerceCollection((Collection) value);
+    }
+
+    return value.toString();
+  }
+
+  private String coerceCollection(Collection value) {
+    Iterator<?> it = value.iterator();
+    if (!it.hasNext()) {
+      return "[]";
+    }
+
+    StringBuilder sb = new StringBuilder();
+
+    sb.append('[');
+    for (;;) {
+      Object e = it.next();
+      sb.append(e == this ? "(this Collection)" : e);
+      if (sb.length() > MAX_COLLECTION_STRING_LENGTH) {
+        return sb.append(", ...]").toString();
+      }
+      if (!it.hasNext()) {
+        return sb.append(']').toString();
+      }
+      sb.append(',');
+      sb.append(' ');
+    }
   }
 
   @Override

diff --git a/src/test/java/com/hubspot/jinjava/lib/exptest/IsEqualToExpTestTest.java b/src/test/java/com/hubspot/jinjava/lib/exptest/IsEqualToExpTestTest.java
@@ -3,7 +3,9 @@
 import static org.assertj.core.api.Assertions.assertThat;
 
 import com.hubspot.jinjava.BaseJinjavaTest;
+import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import org.junit.Test;
 
 public class IsEqualToExpTestTest extends BaseJinjavaTest {
@@ -35,6 +37,50 @@ public void itEquatesStrings() {
       .isEqualTo("false");
   }
 
+  @Test
+  public void itEquatesCollectionsToStrings() {
+    assertThat(
+        jinjava.render(
+          String.format(EQUAL_TEMPLATE, "\"[1, 2, 3]\"", "[1, 2, 3]"),
+          new HashMap<>()
+        )
+      )
+      .isEqualTo("true");
+
+    assertThat(
+        jinjava.render(
+          String.format(EQUAL_TEMPLATE, "\"[1, 2, 3]\"", "[1, 2, 4]"),
+          new HashMap<>()
+        )
+      )
+      .isEqualTo("false");
+  }
+
+  @Test
+  public void itEquatesLargeCollectionsAndStrings() {
+    assertThat(compareStringAndCollection(100_000)).isEqualTo("true");
+  }
+
+  @Test
+  public void itDoesNotEquateHugeCollectionsAndStrings() {
+    assertThat(compareStringAndCollection(500_000)).isEqualTo("false");
+  }
+
+  private String compareStringAndCollection(int size) {
+    List<Integer> bigList = new ArrayList<>();
+
+    for (int i = 0; i < size; i++) {
+      bigList.add(1);
+    }
+
+    String bigString = bigList.toString();
+
+    return jinjava.render(
+      String.format(EQUAL_TEMPLATE, "\"" + bigString + "\"", bigString),
+      new HashMap<>()
+    );
+  }
+
   @Test
   public void itEquatesBooleans() {
     assertThat(