feat: Add Decimal128Value (#799)

* WIP: Decimal128Value.

* WIP: decimal128 values. next: add quadruple + compare. next: add tests.

* Add quadruple and quadruple_builder.

* Implement comparison logic.

* Fix bug and add integration tests.

* Add unit tests.

* clang-format.

* Fix the NumberEquals logic.

* Port the missing tests from Android.

* Port more integration tests from Android.

* Address feedback.

* Update Quadruple library and re-enable tests (passing now).

* Fix FIRDecimal128Value.isEqual to handle -/+0.

Author: ehsannas

FirebaseFirestoreInternal/FirebaseFirestore/FIRDecimal128Value.h

@@ -0,0 +1,15 @@
+// Copyright 2025 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#import <FirebaseFirestoreInternal/FIRDecimal128Value.h>

Firestore/CHANGELOG.md

@@ -1,6 +1,6 @@
 # Unreleased
 - [feature] Adds support for the following new types: `MinKey`, `MaxKey`, `RegexValue`,
-  `Int32Value`, `BSONObjectId`, `BSONTimestamp`, and `BSONBinaryData`. (#14800)
+  `Int32Value`, `Decimal128Value`, `BSONObjectId`, `BSONTimestamp`, and `BSONBinaryData`. (#14800)
 
 # 11.12.0
 - [fixed] Fixed the `null` value handling in `isNotEqualTo` and `notIn` filters.

Firestore/Example/Tests/API/FIRBsonTypesUnitTests.mm

@@ -17,6 +17,7 @@
 #import <FirebaseFirestore/FIRBSONBinaryData.h>
 #import <FirebaseFirestore/FIRBSONObjectId.h>
 #import <FirebaseFirestore/FIRBSONTimestamp.h>
+#import <FirebaseFirestore/FIRDecimal128Value.h>
 #import <FirebaseFirestore/FIRFieldValue.h>
 #import <FirebaseFirestore/FIRInt32Value.h>
 #import <FirebaseFirestore/FIRMaxKey.h>
@@ -75,6 +76,39 @@ - (void)testCreateAndReadAndCompareInt32Value {
   XCTAssertFalse([val1 isEqual:val3]);
 }
 
+- (void)testCreateAndReadAndCompareDecimal128Value {
+  FIRDecimal128Value *val1 = [[FIRDecimal128Value alloc] initWithValue:@"1.2e3"];
+  FIRDecimal128Value *val2 = [[FIRDecimal128Value alloc] initWithValue:@"12e2"];
+  FIRDecimal128Value *val3 = [[FIRDecimal128Value alloc] initWithValue:@"0.12e4"];
+  FIRDecimal128Value *val4 = [[FIRDecimal128Value alloc] initWithValue:@"12000e-1"];
+  FIRDecimal128Value *val5 = [[FIRDecimal128Value alloc] initWithValue:@"1.2"];
+  FIRDecimal128Value *val6 = [[FIRDecimal128Value alloc] initWithValue:@"NaN"];
+  FIRDecimal128Value *val7 = [[FIRDecimal128Value alloc] initWithValue:@"Infinity"];
+  FIRDecimal128Value *val8 = [[FIRDecimal128Value alloc] initWithValue:@"-Infinity"];
+  FIRDecimal128Value *val9 = [[FIRDecimal128Value alloc] initWithValue:@"NaN"];
+  FIRDecimal128Value *val10 = [[FIRDecimal128Value alloc] initWithValue:@"-0"];
+  FIRDecimal128Value *val11 = [[FIRDecimal128Value alloc] initWithValue:@"0"];
+  FIRDecimal128Value *val12 = [[FIRDecimal128Value alloc] initWithValue:@"-0.0"];
+  FIRDecimal128Value *val13 = [[FIRDecimal128Value alloc] initWithValue:@"0.0"];
+
+  // Test reading the value back
+  XCTAssertEqual(@"1.2e3", val1.value);
+
+  // Test isEqual
+  XCTAssertTrue([val1 isEqual:val2]);
+  XCTAssertTrue([val1 isEqual:val3]);
+  XCTAssertTrue([val1 isEqual:val4]);
+  XCTAssertFalse([val1 isEqual:val5]);
+
+  // Test isEqual for special values.
+  XCTAssertTrue([val6 isEqual:val9]);
+  XCTAssertFalse([val7 isEqual:val8]);
+  XCTAssertFalse([val7 isEqual:val9]);
+  XCTAssertTrue([val10 isEqual:val11]);
+  XCTAssertTrue([val10 isEqual:val12]);
+  XCTAssertTrue([val10 isEqual:val13]);
+}
+
 - (void)testCreateAndReadAndCompareBsonObjectId {
   FIRBSONObjectId *val1 = [[FIRBSONObjectId alloc] initWithValue:@"abcd"];
   FIRBSONObjectId *val2 = [[FIRBSONObjectId alloc] initWithValue:@"abcd"];

Firestore/Source/API/FIRDecimal128Value.mm

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "Firestore/Source/Public/FirebaseFirestore/FIRDecimal128Value.h"
+
+#include "Firestore/core/src/util/quadruple.h"
+#include "Firestore/core/src/util/string_apple.h"
+
+using firebase::firestore::util::MakeString;
+using firebase::firestore::util::Quadruple;
+
+@implementation FIRDecimal128Value
+
+- (instancetype)initWithValue:(NSString *)value {
+  self = [super init];
+  if (self) {
+    _value = [value copy];
+  }
+  return self;
+}
+
+- (BOOL)isEqual:(nullable id)object {
+  if (self == object) {
+    return YES;
+  }
+
+  if (![object isKindOfClass:[FIRDecimal128Value class]]) {
+    return NO;
+  }
+
+  FIRDecimal128Value *other = (FIRDecimal128Value *)object;
+
+  Quadruple lhs = Quadruple();
+  Quadruple rhs = Quadruple();
+  lhs.Parse(MakeString(self.value));
+  rhs.Parse(MakeString(other.value));
+
+  // Firestore considers +0 and -0 to be equal, but `Quadruple::Compare()` does not.
+  if (lhs.Compare(Quadruple(-0.0)) == 0) lhs = Quadruple();
+  if (rhs.Compare(Quadruple(-0.0)) == 0) rhs = Quadruple();
+
+  return lhs.Compare(rhs) == 0;
+}
+
+- (id)copyWithZone:(__unused NSZone *_Nullable)zone {
+  return [[FIRDecimal128Value alloc] initWithValue:self.value];
+}
+
+- (NSString *)description {
+  return [NSString stringWithFormat:@"<FIRDecimal128Value: (%@)>", self.value];
+}
+
+@end

Firestore/Source/API/FSTUserDataReader.mm

@@ -27,6 +27,7 @@
 #import "FIRBSONBinaryData.h"
 #import "FIRBSONObjectId.h"
 #import "FIRBSONTimestamp.h"
+#import "FIRDecimal128Value.h"
 #import "FIRGeoPoint.h"
 #import "FIRInt32Value.h"
 #import "FIRMaxKey.h"
@@ -452,6 +453,20 @@ - (ParsedUpdateData)parsedUpdateData:(id)input {
   return std::move(result);
 }
 
+- (Message<google_firestore_v1_Value>)parseDecimal128Value:(FIRDecimal128Value *)decimal128
+                                                   context:(ParseContext &&)context {
+  __block Message<google_firestore_v1_Value> result;
+  result->which_value_type = google_firestore_v1_Value_map_value_tag;
+  result->map_value = {};
+  result->map_value.fields_count = 1;
+  result->map_value.fields = nanopb::MakeArray<google_firestore_v1_MapValue_FieldsEntry>(1);
+  result->map_value.fields[0].key = nanopb::CopyBytesArray(model::kDecimal128TypeFieldValue);
+  result->map_value.fields[0].value =
+      *[self encodeStringValue:MakeString(decimal128.value)].release();
+
+  return std::move(result);
+}
+
 - (Message<google_firestore_v1_Value>)parseBsonObjectId:(FIRBSONObjectId *)oid
                                                 context:(ParseContext &&)context {
   __block Message<google_firestore_v1_Value> result;
@@ -723,6 +738,9 @@ - (void)parseSentinelFieldValue:(FIRFieldValue *)fieldValue context:(ParseContex
   } else if ([input isKindOfClass:[FIRInt32Value class]]) {
     FIRInt32Value *value = input;
     return [self parseInt32Value:value context:std::move(context)];
+  } else if ([input isKindOfClass:[FIRDecimal128Value class]]) {
+    FIRDecimal128Value *value = input;
+    return [self parseDecimal128Value:value context:std::move(context)];
   } else if ([input isKindOfClass:[FIRBSONObjectId class]]) {
     FIRBSONObjectId *oid = input;
     return [self parseBsonObjectId:oid context:std::move(context)];

Firestore/Source/API/FSTUserDataWriter.mm

@@ -26,6 +26,7 @@
 #include "Firestore/Source/Public/FirebaseFirestore/FIRBSONBinaryData.h"
 #include "Firestore/Source/Public/FirebaseFirestore/FIRBSONObjectId.h"
 #include "Firestore/Source/Public/FirebaseFirestore/FIRBSONTimestamp.h"
+#include "Firestore/Source/Public/FirebaseFirestore/FIRDecimal128Value.h"
 #include "Firestore/Source/Public/FirebaseFirestore/FIRInt32Value.h"
 #include "Firestore/Source/Public/FirebaseFirestore/FIRMaxKey.h"
 #include "Firestore/Source/Public/FirebaseFirestore/FIRMinKey.h"
@@ -58,6 +59,8 @@
 using firebase::firestore::google_protobuf_Timestamp;
 using firebase::firestore::model::kRawBsonTimestampTypeIncrementFieldValue;
 using firebase::firestore::model::kRawBsonTimestampTypeSecondsFieldValue;
+using firebase::firestore::model::kRawDecimal128TypeFieldValue;
+using firebase::firestore::model::kRawInt32TypeFieldValue;
 using firebase::firestore::model::kRawRegexTypeOptionsFieldValue;
 using firebase::firestore::model::kRawRegexTypePatternFieldValue;
 using firebase::firestore::model::kRawVectorValueFieldKey;
@@ -109,7 +112,12 @@ - (id)convertedValue:(const google_firestore_v1_Value &)value {
       return value.boolean_value ? @YES : @NO;
     case TypeOrder::kNumber:
       if (value.which_value_type == google_firestore_v1_Value_map_value_tag) {
-        return [self convertedInt32:value.map_value];
+        absl::string_view key = MakeStringView(value.map_value.fields[0].key);
+        if (key.compare(absl::string_view(kRawInt32TypeFieldValue)) == 0) {
+          return [self convertedInt32:value.map_value];
+        } else if (key.compare(absl::string_view(kRawDecimal128TypeFieldValue)) == 0) {
+          return [self convertedDecimal128Value:value.map_value];
+        }
       }
       return value.which_value_type == google_firestore_v1_Value_integer_value_tag
                  ? @(value.integer_value)
@@ -157,7 +165,7 @@ - (FIRVectorValue *)convertedVector:(const google_firestore_v1_MapValue &)mapVal
   for (pb_size_t i = 0; i < mapValue.fields_count; ++i) {
     absl::string_view key = MakeStringView(mapValue.fields[i].key);
     const google_firestore_v1_Value &value = mapValue.fields[i].value;
-    if ((0 == key.compare(absl::string_view(kRawVectorValueFieldKey))) &&
+    if ((key.compare(absl::string_view(kRawVectorValueFieldKey)) == 0) &&
         value.which_value_type == google_firestore_v1_Value_array_value_tag) {
       return [FIRFieldValue vectorWithArray:[self convertedArray:value.array_value]];
     }
@@ -174,11 +182,11 @@ - (FIRRegexValue *)convertedRegex:(const google_firestore_v1_MapValue &)mapValue
       for (pb_size_t i = 0; i < innerValue.map_value.fields_count; ++i) {
         absl::string_view key = MakeStringView(innerValue.map_value.fields[i].key);
         const google_firestore_v1_Value &value = innerValue.map_value.fields[i].value;
-        if ((0 == key.compare(absl::string_view(kRawRegexTypePatternFieldValue))) &&
+        if ((key.compare(absl::string_view(kRawRegexTypePatternFieldValue)) == 0) &&
             value.which_value_type == google_firestore_v1_Value_string_value_tag) {
           pattern = MakeNSString(MakeStringView(value.string_value));
         }
-        if ((0 == key.compare(absl::string_view(kRawRegexTypeOptionsFieldValue))) &&
+        if ((key.compare(absl::string_view(kRawRegexTypeOptionsFieldValue)) == 0) &&
             value.which_value_type == google_firestore_v1_Value_string_value_tag) {
           options = MakeNSString(MakeStringView(value.string_value));
         }
@@ -198,6 +206,18 @@ - (FIRInt32Value *)convertedInt32:(const google_firestore_v1_MapValue &)mapValue
   return [[FIRInt32Value alloc] initWithValue:value];
 }
 
+- (FIRDecimal128Value *)convertedDecimal128Value:(const google_firestore_v1_MapValue &)mapValue {
+  NSString *decimalString = @"";
+  if (mapValue.fields_count == 1) {
+    const google_firestore_v1_Value &decimalValue = mapValue.fields[0].value;
+    if (decimalValue.which_value_type == google_firestore_v1_Value_string_value_tag) {
+      decimalString = MakeNSString(MakeStringView(decimalValue.string_value));
+    }
+  }
+
+  return [[FIRDecimal128Value alloc] initWithValue:decimalString];
+}
+
 - (FIRBSONObjectId *)convertedBsonObjectId:(const google_firestore_v1_MapValue &)mapValue {
   NSString *oid = @"";
   if (mapValue.fields_count == 1) {
@@ -219,12 +239,12 @@ - (FIRBSONTimestamp *)convertedBsonTimestamp:(const google_firestore_v1_MapValue
       for (pb_size_t i = 0; i < innerValue.map_value.fields_count; ++i) {
         absl::string_view key = MakeStringView(innerValue.map_value.fields[i].key);
         const google_firestore_v1_Value &value = innerValue.map_value.fields[i].value;
-        if ((0 == key.compare(absl::string_view(kRawBsonTimestampTypeSecondsFieldValue))) &&
+        if ((key.compare(absl::string_view(kRawBsonTimestampTypeSecondsFieldValue)) == 0) &&
             value.which_value_type == google_firestore_v1_Value_integer_value_tag) {
           // The value from the server is guaranteed to fit in a 32-bit unsigned integer.
           seconds = static_cast<uint32_t>(value.integer_value);
         }
-        if ((0 == key.compare(absl::string_view(kRawBsonTimestampTypeIncrementFieldValue))) &&
+        if ((key.compare(absl::string_view(kRawBsonTimestampTypeIncrementFieldValue)) == 0) &&
             value.which_value_type == google_firestore_v1_Value_integer_value_tag) {
           // The value from the server is guaranteed to fit in a 32-bit unsigned integer.
           increment = static_cast<uint32_t>(value.integer_value);

Firestore/Source/Public/FirebaseFirestore/FIRDecimal128Value.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ * Represents a 128-bit decimal number type in Firestore documents.
+ */
+NS_SWIFT_SENDABLE
+NS_SWIFT_NAME(Decimal128Value)
+__attribute__((objc_subclassing_restricted))
+@interface FIRDecimal128Value : NSObject<NSCopying>
+
+/** The string representation of the 128-bit decimal value. */
+@property(nonatomic, copy, readonly) NSString *value;
+
+/** :nodoc: */
+- (instancetype)init NS_UNAVAILABLE;
+
+/**
+ * Creates a `Decimal128Value` with the given value.
+ * @param value The string representation of the number to be stored.
+ */
+- (instancetype)initWithValue:(NSString *)value NS_SWIFT_NAME(init(_:));
+
+/** Returns true if the given object is equal to this, and false otherwise. */
+- (BOOL)isEqual:(nullable id)object;
+
+@end
+
+NS_ASSUME_NONNULL_END

Firestore/Swift/Source/Codable/CodablePassThroughTypes.swift

@@ -37,6 +37,7 @@ struct FirestorePassthroughTypes: StructureCodingPassthroughTypeResolver {
       t is MaxKey ||
       t is RegexValue ||
       t is Int32Value ||
+      t is Decimal128Value ||
       t is BSONObjectId ||
       t is BSONTimestamp ||
       t is BSONBinaryData

Firestore/Swift/Source/Codable/Decimal128Value+Codable.swift

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#if SWIFT_PACKAGE
+  @_exported import FirebaseFirestoreInternalWrapper
+#else
+  @_exported import FirebaseFirestoreInternal
+#endif // SWIFT_PACKAGE
+
+/**
+ * A protocol describing the encodable properties of a Decimal128Value.
+ *
+ * Note: this protocol exists as a workaround for the Swift compiler: if the Decimal128Value class
+ * was extended directly to conform to Codable, the methods implementing the protocol would be need
+ * to be marked required but that can't be done in an extension. Declaring the extension on the
+ * protocol sidesteps this issue.
+ */
+private protocol CodableDecimal128Value: Codable {
+  var value: String { get }
+
+  init(_ value: String)
+}
+
+/** The keys in a Decimal128Value. Must match the properties of Decimal128Value. */
+private enum Decimal128ValueKeys: String, CodingKey {
+  case value
+}
+
+/**
+ * An extension of Decimal128Value that implements the behavior of the Codable protocol.
+ *
+ * Note: this is implemented manually here because the Swift compiler can't synthesize these methods
+ * when declaring an extension to conform to Codable.
+ */
+extension CodableDecimal128Value {
+  public init(from decoder: Decoder) throws {
+    let container = try decoder.container(keyedBy: Decimal128ValueKeys.self)
+    let value = try container.decode(String.self, forKey: .value)
+    self.init(value)
+  }
+
+  public func encode(to encoder: Encoder) throws {
+    var container = encoder.container(keyedBy: Decimal128ValueKeys.self)
+    try container.encode(value, forKey: .value)
+  }
+}
+
+/** Extends Decimal128Value to conform to Codable. */
+extension FirebaseFirestore.Decimal128Value: FirebaseFirestore.CodableDecimal128Value {}