Truncate strings or values of type variables in toString method tha…

…t are longer than a defined length

value-annotations/src/org/immutables/value/Value.java

@@ -1405,6 +1405,12 @@
      */
     Class<? extends Annotation>[] allowedClasspathAnnotations() default {};
 
+    /**
+     * Setting to cut strings longer than a defined length when calling the toString method.
+     * @return string limit
+     */
+    int limitStringLengthInToString() default 1000;
+
     /**
      * If implementation visibility is more restrictive than visibility of abstract value type, then
      * implementation type will not be exposed as a return type of {@code build()} or {@code of()}

value-processor/src/org/immutables/value/processor/Immutables.generator

@@ -3165,6 +3165,14 @@ private int [disambiguateAccessor type 'computeHashCode']() {
 [template generateToString Type type]
 [if not type.toStringDefined]
 
+static String objectToString(Object input, int limit) {
+    if (input == null) {
+        return null;
+    }
+    String output = input.toString();
+    return output.length() > limit ? output.substring(0, limit).concat("…") : output;
+}
+
 /**
  * Prints the immutable value {@code [type.name]}[if type.equivalenceAttributes] with attribute values[/if].
  * @return A string representation of the value
@@ -4380,6 +4388,6 @@ private static final long serialVersionUID = [literal serialVersion];
 
 [template castObject String typename][if typename ne 'java.lang.Object']([typename]) [/if][/template]
 
-[template maybeMasked Attribute a String value][if a.redactedMask][literal.string a.redactedMask][else][value][/if][/template]
+[template maybeMasked Attribute a String value][if a.redactedMask][literal.string a.redactedMask][else if a.limitStringLengthInToString and (a.stringType or a.optionalStringType)]objectToString([value], [a.limitStringLengthInToString])[else if a.limitStringLengthInToString and a.hasTypeVariables]objectToString([value], [a.limitStringLengthInToString])[else][value][/if][/template]
 
 [template hiddenMutableState Type type][if type allowsClasspathAnnotation 'com.google.errorprone.annotations.Immutable']@SuppressWarnings("Immutable")[/if][/template]

value-processor/src/org/immutables/value/processor/meta/StyleInfo.java

@@ -399,6 +399,9 @@ public Class<? extends Annotation>[] allowedClasspathAnnotations() {
     throw new UnsupportedOperationException("Use StyleInfo.allowedClasspathAnnotationsNames() instead");
   }
 
+  @Value.Parameter
+  public abstract int limitStringLengthInToString();
+
   static StyleInfo infoFrom(StyleMirror input) {
     return ImmutableStyleInfo.of(
         input.get(),
@@ -481,6 +484,7 @@ static StyleInfo infoFrom(StyleMirror input) {
         input.addAllBuilder(),
         input.getBuilders(),
         input.nullableAnnotation(),
-        ImmutableSet.copyOf(input.allowedClasspathAnnotationsName()));
+        ImmutableSet.copyOf(input.allowedClasspathAnnotationsName()),
+        input.limitStringLengthInToString());
   }
 }

value-processor/src/org/immutables/value/processor/meta/ValueAttribute.java

@@ -167,6 +167,10 @@ public boolean isStringType() {
     return String.class.getName().equals(rawTypeName);
   }
 
+  public boolean isOptionalStringType() {
+    return isOptionalType() && getGenericArgs().equals("<" + String.class.getName() + ">");
+  }
+
   public boolean charType() {
     return returnType.getKind() == TypeKind.CHAR;
   }
@@ -1857,6 +1861,14 @@ public String atNullableInSupertypeLocal() {
     return nullabilityInSupertype != null ? nullabilityInSupertype.asLocalPrefix() : "";
   }
 
+  public int getLimitStringLengthInToString() {
+    return protoclass().styles().style().limitStringLengthInToString();
+  }
+
+  public boolean isLimitStringLengthInToString() {
+    return protoclass().styles().style().limitStringLengthInToString() > 0;
+  }
+
   enum ToName implements Function<ValueAttribute, String> {
     FUNCTION;
     @Override

value-processor/src/org/immutables/value/processor/meta/ValueMirrors.java

@@ -249,6 +249,8 @@ private ValueMirrors() {}
 
     String nullableAnnotation() default "Nullable";
 
+    int limitStringLengthInToString() default 1000;
+
     Class<? extends Annotation>[] allowedClasspathAnnotations() default {};
 
     public enum ImplementationVisibility {