scrooge-generator: Add the ability to unset multiple fields at once

Problem

Sometimes customers want to unset many parts of their struct.

Solution

Provide an API to do a lot of unsetting all at once.

JIRA Issues: CSL-12001

Differential Revision: https://phabricator.twitter.biz/D911135

CHANGELOG.rst

@@ -20,6 +20,8 @@ New Features
 
 * scrooge-generator: Add @.generated annotation to Swift generated code ``PHAB_ID=D879262``
 
+* scrooge-generator: Provide a `$STRUCT#unsetFields` method to allow bulk unsets ``PHAB_ID=D911135``
+
 * scrooge-generator: support thrift validations on nested fields that are struct, union, and
   exception ``PHAB_ID=D911262``
 

scrooge-generator-tests/src/test/resources/gold_file_output_scala/com/twitter/scrooge/test/gold/thriftscala/AnotherException.scala

@@ -279,6 +279,18 @@ class AnotherException(
     )
   }
 
+  /**
+   * If the specified fields are optional, they are set to None.  Otherwise, if the fields are
+   * known, they are reverted to their default values; if the fields are unknown, they are removed
+   * from the passthroughFields map, if present.
+   */
+  def unsetFields(_fieldIds: Set[Short]): AnotherException = {
+    new AnotherException(
+      if (_fieldIds(1)) 0 else this.errorCode,
+      _passthroughFields -- _fieldIds
+    )
+  }
+
   /**
    * If the specified field is optional, it is set to None.  Otherwise, if the field is
    * known, it is reverted to its default value; if the field is unknown, it is removed

scrooge-generator-tests/src/test/resources/gold_file_output_scala/com/twitter/scrooge/test/gold/thriftscala/CollectionId.scala

@@ -384,6 +384,18 @@ trait CollectionId
     )
   }
 
+  /**
+   * If the specified fields are optional, they are set to None.  Otherwise, if the fields are
+   * known, they are reverted to their default values; if the fields are unknown, they are removed
+   * from the passthroughFields map, if present.
+   */
+  def unsetFields(_fieldIds: Set[Short]): CollectionId = {
+    new Immutable(
+      if (_fieldIds(1)) 0L else this.collectionLongId,
+      _passthroughFields -- _fieldIds
+    )
+  }
+
   /**
    * If the specified field is optional, it is set to None.  Otherwise, if the field is
    * known, it is reverted to its default value; if the field is unknown, it is removed

scrooge-generator-tests/src/test/resources/gold_file_output_scala/com/twitter/scrooge/test/gold/thriftscala/OverCapacityException.scala

@@ -283,6 +283,18 @@ class OverCapacityException(
     )
   }
 
+  /**
+   * If the specified fields are optional, they are set to None.  Otherwise, if the fields are
+   * known, they are reverted to their default values; if the fields are unknown, they are removed
+   * from the passthroughFields map, if present.
+   */
+  def unsetFields(_fieldIds: Set[Short]): OverCapacityException = {
+    new OverCapacityException(
+      if (_fieldIds(1)) 0 else this.chillTimeSeconds,
+      _passthroughFields -- _fieldIds
+    )
+  }
+
   /**
    * If the specified field is optional, it is set to None.  Otherwise, if the field is
    * known, it is reverted to its default value; if the field is unknown, it is removed

scrooge-generator-tests/src/test/resources/gold_file_output_scala/com/twitter/scrooge/test/gold/thriftscala/Recursive.scala

@@ -452,6 +452,19 @@ trait Recursive
     )
   }
 
+  /**
+   * If the specified fields are optional, they are set to None.  Otherwise, if the fields are
+   * known, they are reverted to their default values; if the fields are unknown, they are removed
+   * from the passthroughFields map, if present.
+   */
+  def unsetFields(_fieldIds: Set[Short]): Recursive = {
+    new Immutable(
+      if (_fieldIds(1)) 0L else this.id,
+      if (_fieldIds(2)) _root_.scala.None else this.recRequest,
+      _passthroughFields -- _fieldIds
+    )
+  }
+
   /**
    * If the specified field is optional, it is set to None.  Otherwise, if the field is
    * known, it is reverted to its default value; if the field is unknown, it is removed

scrooge-generator-tests/src/test/resources/gold_file_output_scala/com/twitter/scrooge/test/gold/thriftscala/Request.scala

@@ -1559,6 +1559,33 @@ trait Request
     )
   }
 
+  /**
+   * If the specified fields are optional, they are set to None.  Otherwise, if the fields are
+   * known, they are reverted to their default values; if the fields are unknown, they are removed
+   * from the passthroughFields map, if present.
+   */
+  def unsetFields(_fieldIds: Set[Short]): Request = {
+    new Immutable(
+      if (_fieldIds(1)) _root_.scala.collection.immutable.Nil else this.aList,
+      if (_fieldIds(2)) _root_.scala.collection.immutable.Set.empty else this.aSet,
+      if (_fieldIds(3)) _root_.scala.collection.immutable.Map.empty else this.aMap,
+      if (_fieldIds(4)) _root_.scala.None else this.aRequest,
+      if (_fieldIds(5)) _root_.scala.collection.immutable.Nil else this.subRequests,
+      if (_fieldIds(6)) "the_default" else this._default,
+      if (_fieldIds(7)) _root_.scala.None else this.noComment,
+      if (_fieldIds(8)) _root_.scala.None else this.doubleSlashComment,
+      if (_fieldIds(9)) _root_.scala.None else this.hashtagComment,
+      if (_fieldIds(10)) _root_.scala.None else this.singleAsteriskComment,
+      if (_fieldIds(11)) _root_.scala.None else this.docStringComment,
+      if (_fieldIds(12)) _root_.scala.None else this.recRequest,
+      if (_fieldIds(13)) null else this.requiredField,
+      if (_fieldIds(14)) _root_.scala.None else this.constructionRequiredField,
+      if (_fieldIds(15)) _root_.scala.None else this.anInt8,
+      if (_fieldIds(16)) _root_.scala.None else this.aBinaryField,
+      _passthroughFields -- _fieldIds
+    )
+  }
+
   /**
    * If the specified field is optional, it is set to None.  Otherwise, if the field is
    * known, it is reverted to its default value; if the field is unknown, it is removed

scrooge-generator-tests/src/test/resources/gold_file_output_scala/com/twitter/scrooge/test/gold/thriftscala/RequestException.scala

@@ -285,6 +285,18 @@ class RequestException(
     )
   }
 
+  /**
+   * If the specified fields are optional, they are set to None.  Otherwise, if the fields are
+   * known, they are reverted to their default values; if the fields are unknown, they are removed
+   * from the passthroughFields map, if present.
+   */
+  def unsetFields(_fieldIds: Set[Short]): RequestException = {
+    new RequestException(
+      if (_fieldIds(1)) null else this.message,
+      _passthroughFields -- _fieldIds
+    )
+  }
+
   /**
    * If the specified field is optional, it is set to None.  Otherwise, if the field is
    * known, it is reverted to its default value; if the field is unknown, it is removed

scrooge-generator-tests/src/test/resources/gold_file_output_scala/com/twitter/scrooge/test/gold/thriftscala/Response.scala

@@ -463,6 +463,19 @@ trait Response
     )
   }
 
+  /**
+   * If the specified fields are optional, they are set to None.  Otherwise, if the fields are
+   * known, they are reverted to their default values; if the fields are unknown, they are removed
+   * from the passthroughFields map, if present.
+   */
+  def unsetFields(_fieldIds: Set[Short]): Response = {
+    new Immutable(
+      if (_fieldIds(1)) 0 else this.statusCode,
+      if (_fieldIds(2)) null else this.responseUnion,
+      _passthroughFields -- _fieldIds
+    )
+  }
+
   /**
    * If the specified field is optional, it is set to None.  Otherwise, if the field is
    * known, it is reverted to its default value; if the field is unknown, it is removed

scrooge-generator-tests/src/test/scala/com/twitter/scrooge/backend/ImmutableStructSpec.scala

@@ -66,5 +66,34 @@ class ImmutableStructSpec extends Spec {
       )
       Xtruct.Immutable.metaData.fields.map(_.name).toSet must be(expectedFieldNames)
     }
+
+    "unset non-optional field" in {
+      val xtruct = Xtruct(
+        "string_thing",
+        10.toByte,
+        100,
+        1000L
+      )
+      xtruct.unsetField(4) must be(Xtruct("string_thing", 0.toByte, 100, 1000L))
+    }
+
+    "unset optional field" in {
+      val boolTest = OptionalInt(
+        "my_name",
+        Some(32)
+      )
+      boolTest.unsetField(2) must be(OptionalInt("my_name", None))
+    }
+
+    "unset fields" in {
+      val xtruct = Xtruct(
+        "string_thing",
+        10.toByte,
+        100,
+        1000L
+      )
+
+      xtruct.unsetFields(Set(1, 4, 9)) must be(Xtruct(null, 0.toByte, 0, 1000L))
+    }
   }
 }

scrooge-generator/src/main/resources/scalagen/struct.mustache

@@ -767,6 +767,20 @@ class {{StructName}}(
     )
   }
 
+  /**
+   * If the specified fields are optional, they are set to None.  Otherwise, if the fields are
+   * known, they are reverted to their default values; if the fields are unknown, they are removed
+   * from the passthroughFields map, if present.
+   */
+  def unsetFields(_fieldIds: Set[Short]): {{StructName}} = {
+    new {{InstanceClassName}}(
+{{#fields}}
+      if (_fieldIds({{id}})) {{#optional}}_root_.scala.None{{/optional}}{{^optional}}{{defaultReadValue}}{{/optional}} else this.{{fieldName}},
+{{/fields}}
+      _passthroughFields -- _fieldIds
+    )
+  }
+
   /**
    * If the specified field is optional, it is set to None.  Otherwise, if the field is
    * known, it is reverted to its default value; if the field is unknown, it is removed