grand PR to port the remaining paths (FieldPath and ResourcePath). (#865)

* naively remove FSTPath import and source/test files.

* port FieldPath, part I

* port FieldPath, part II

* port ResourcePath, part I

* port ResourcePath, part II

* the grand commit to fix build errors

* use testutil:: helper instead of those from FSTHelpers

* fix test and lint

* use c_str in errmsg directly

* fix

* fix

* make code clean

* fix integration test I missed

* fix to avoid naming collision in preprocessor

* address changes

* address changes

* address changes

* fix: fieldMask are actually shared with different context.

* address changes

* address changes

5 files changed, 146 insertions, 148 deletions

diff --git a/Firestore/Example/Tests/Core/FSTEventManagerTests.mm b/Firestore/Example/Tests/Core/FSTEventManagerTests.mm
index f5f7b5b..952d01f 100644
--- a/Firestore/Example/Tests/Core/FSTEventManagerTests.mm
+++ b/Firestore/Example/Tests/Core/FSTEventManagerTests.mm
@@ -52,7 +52,7 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testHandlesManyListenersPerQuery {
-  FSTQuery *query = FSTTestQuery(@"foo/bar");
+  FSTQuery *query = FSTTestQuery("foo/bar");
   FSTQueryListener *listener1 = [self noopListenerForQuery:query];
   FSTQueryListener *listener2 = [self noopListenerForQuery:query];
 
@@ -73,7 +73,7 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testHandlesUnlistenOnUnknownListenerGracefully {
-  FSTQuery *query = FSTTestQuery(@"foo/bar");
+  FSTQuery *query = FSTTestQuery("foo/bar");
   FSTQueryListener *listener = [self noopListenerForQuery:query];
 
   FSTSyncEngine *syncEngineMock = OCMStrictClassMock([FSTSyncEngine class]);
@@ -95,8 +95,8 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testNotifiesListenersInTheRightOrder {
-  FSTQuery *query1 = FSTTestQuery(@"foo/bar");
-  FSTQuery *query2 = FSTTestQuery(@"bar/baz");
+  FSTQuery *query1 = FSTTestQuery("foo/bar");
+  FSTQuery *query2 = FSTTestQuery("bar/baz");
   NSMutableArray *eventOrder = [NSMutableArray array];
 
   FSTQueryListener *listener1 = [self makeMockListenerForQuery:query1
@@ -135,7 +135,7 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testWillForwardOnlineStateChanges {
-  FSTQuery *query = FSTTestQuery(@"foo/bar");
+  FSTQuery *query = FSTTestQuery("foo/bar");
   FSTQueryListener *fakeListener = OCMClassMock([FSTQueryListener class]);
   NSMutableArray *events = [NSMutableArray array];
   OCMStub([fakeListener query]).andReturn(query);
diff --git a/Firestore/Example/Tests/Core/FSTQueryListenerTests.mm b/Firestore/Example/Tests/Core/FSTQueryListenerTests.mm
index 1b26360..55c4219 100644
--- a/Firestore/Example/Tests/Core/FSTQueryListenerTests.mm
+++ b/Firestore/Example/Tests/Core/FSTQueryListenerTests.mm
@@ -45,7 +45,7 @@ NS_ASSUME_NONNULL_BEGIN
   NSMutableArray<FSTViewSnapshot *> *accum = [NSMutableArray array];
   NSMutableArray<FSTViewSnapshot *> *otherAccum = [NSMutableArray array];
 
-  FSTQuery *query = FSTTestQuery(@"rooms");
+  FSTQuery *query = FSTTestQuery("rooms");
   FSTDocument *doc1 = FSTTestDoc(@"rooms/Eros", 1, @{@"name" : @"Eros"}, NO);
   FSTDocument *doc2 = FSTTestDoc(@"rooms/Hades", 2, @{@"name" : @"Hades"}, NO);
   FSTDocument *doc2prime =
@@ -88,7 +88,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)testRaisesErrorEvent {
   NSMutableArray<NSError *> *accum = [NSMutableArray array];
-  FSTQuery *query = FSTTestQuery(@"rooms/Eros");
+  FSTQuery *query = FSTTestQuery("rooms/Eros");
 
   FSTQueryListener *listener = [self listenToQuery:query
                                            handler:^(FSTViewSnapshot *snapshot, NSError *error) {
@@ -104,7 +104,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)testRaisesEventForEmptyCollectionAfterSync {
   NSMutableArray<FSTViewSnapshot *> *accum = [NSMutableArray array];
-  FSTQuery *query = FSTTestQuery(@"rooms");
+  FSTQuery *query = FSTTestQuery("rooms");
 
   FSTQueryListener *listener = [self listenToQuery:query accumulatingSnapshots:accum];
 
@@ -126,7 +126,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)testMutingAsyncListenerPreventsAllSubsequentEvents {
   NSMutableArray<FSTViewSnapshot *> *accum = [NSMutableArray array];
 
-  FSTQuery *query = FSTTestQuery(@"rooms/Eros");
+  FSTQuery *query = FSTTestQuery("rooms/Eros");
   FSTDocument *doc1 = FSTTestDoc(@"rooms/Eros", 3, @{@"name" : @"Eros"}, NO);
   FSTDocument *doc2 = FSTTestDoc(@"rooms/Eros", 4, @{@"name" : @"Eros2"}, NO);
 
@@ -166,7 +166,7 @@ NS_ASSUME_NONNULL_BEGIN
   NSMutableArray<FSTViewSnapshot *> *filteredAccum = [NSMutableArray array];
   NSMutableArray<FSTViewSnapshot *> *fullAccum = [NSMutableArray array];
 
-  FSTQuery *query = FSTTestQuery(@"rooms");
+  FSTQuery *query = FSTTestQuery("rooms");
   FSTDocument *doc1 = FSTTestDoc(@"rooms/Eros", 1, @{@"name" : @"Eros"}, NO);
   FSTDocument *doc2 = FSTTestDoc(@"rooms/Hades", 2, @{@"name" : @"Hades"}, NO);
 
@@ -204,7 +204,7 @@ NS_ASSUME_NONNULL_BEGIN
   NSMutableArray<FSTViewSnapshot *> *filteredAccum = [NSMutableArray array];
   NSMutableArray<FSTViewSnapshot *> *fullAccum = [NSMutableArray array];
 
-  FSTQuery *query = FSTTestQuery(@"rooms");
+  FSTQuery *query = FSTTestQuery("rooms");
   FSTDocument *doc1 = FSTTestDoc(@"rooms/Eros", 1, @{@"name" : @"Eros"}, YES);
   FSTDocument *doc2 = FSTTestDoc(@"rooms/Hades", 2, @{@"name" : @"Hades"}, NO);
   FSTDocument *doc1Prime = FSTTestDoc(@"rooms/Eros", 1, @{@"name" : @"Eros"}, NO);
@@ -253,7 +253,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)testRaisesQueryMetadataEventsOnlyWhenHasPendingWritesOnTheQueryChanges {
   NSMutableArray<FSTViewSnapshot *> *fullAccum = [NSMutableArray array];
 
-  FSTQuery *query = FSTTestQuery(@"rooms");
+  FSTQuery *query = FSTTestQuery("rooms");
   FSTDocument *doc1 = FSTTestDoc(@"rooms/Eros", 1, @{@"name" : @"Eros"}, YES);
   FSTDocument *doc2 = FSTTestDoc(@"rooms/Hades", 2, @{@"name" : @"Hades"}, YES);
   FSTDocument *doc1Prime = FSTTestDoc(@"rooms/Eros", 1, @{@"name" : @"Eros"}, NO);
@@ -290,7 +290,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)testMetadataOnlyDocumentChangesAreFilteredOutWhenIncludeDocumentMetadataChangesIsFalse {
   NSMutableArray<FSTViewSnapshot *> *filteredAccum = [NSMutableArray array];
 
-  FSTQuery *query = FSTTestQuery(@"rooms");
+  FSTQuery *query = FSTTestQuery("rooms");
   FSTDocument *doc1 = FSTTestDoc(@"rooms/Eros", 1, @{@"name" : @"Eros"}, YES);
   FSTDocument *doc2 = FSTTestDoc(@"rooms/Hades", 2, @{@"name" : @"Hades"}, NO);
   FSTDocument *doc1Prime = FSTTestDoc(@"rooms/Eros", 1, @{@"name" : @"Eros"}, NO);
@@ -322,7 +322,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)testWillWaitForSyncIfOnline {
   NSMutableArray<FSTViewSnapshot *> *events = [NSMutableArray array];
 
-  FSTQuery *query = FSTTestQuery(@"rooms");
+  FSTQuery *query = FSTTestQuery("rooms");
   FSTDocument *doc1 = FSTTestDoc(@"rooms/Eros", 1, @{@"name" : @"Eros"}, NO);
   FSTDocument *doc2 = FSTTestDoc(@"rooms/Hades", 2, @{@"name" : @"Hades"}, NO);
   FSTQueryListener *listener =
@@ -365,7 +365,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)testWillRaiseInitialEventWhenGoingOffline {
   NSMutableArray<FSTViewSnapshot *> *events = [NSMutableArray array];
 
-  FSTQuery *query = FSTTestQuery(@"rooms");
+  FSTQuery *query = FSTTestQuery("rooms");
   FSTDocument *doc1 = FSTTestDoc(@"rooms/Eros", 1, @{@"name" : @"Eros"}, NO);
   FSTDocument *doc2 = FSTTestDoc(@"rooms/Hades", 2, @{@"name" : @"Hades"}, NO);
   FSTQueryListener *listener =
@@ -411,7 +411,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)testWillRaiseInitialEventWhenGoingOfflineAndThereAreNoDocs {
   NSMutableArray<FSTViewSnapshot *> *events = [NSMutableArray array];
 
-  FSTQuery *query = FSTTestQuery(@"rooms");
+  FSTQuery *query = FSTTestQuery("rooms");
   FSTQueryListener *listener = [self listenToQuery:query
                                            options:[FSTListenOptions defaultOptions]
                              accumulatingSnapshots:events];
@@ -437,7 +437,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)testWillRaiseInitialEventWhenStartingOfflineAndThereAreNoDocs {
   NSMutableArray<FSTViewSnapshot *> *events = [NSMutableArray array];
 
-  FSTQuery *query = FSTTestQuery(@"rooms");
+  FSTQuery *query = FSTTestQuery("rooms");
   FSTQueryListener *listener = [self listenToQuery:query
                                            options:[FSTListenOptions defaultOptions]
                              accumulatingSnapshots:events];
diff --git a/Firestore/Example/Tests/Core/FSTQueryTests.mm b/Firestore/Example/Tests/Core/FSTQueryTests.mm
index 5f6d279..8b5b524 100644
--- a/Firestore/Example/Tests/Core/FSTQueryTests.mm
+++ b/Firestore/Example/Tests/Core/FSTQueryTests.mm
@@ -21,7 +21,6 @@
 #import "Firestore/Source/API/FIRFirestore+Internal.h"
 #import "Firestore/Source/Model/FSTDocument.h"
 #import "Firestore/Source/Model/FSTDocumentKey.h"
-#import "Firestore/Source/Model/FSTPath.h"
 
 #import "Firestore/Example/Tests/Util/FSTHelpers.h"
 
@@ -30,6 +29,7 @@
 #include "Firestore/core/src/firebase/firestore/model/resource_path.h"
 #include "Firestore/core/src/firebase/firestore/util/string_apple.h"
 #include "Firestore/core/test/firebase/firestore/testutil/testutil.h"
+#include "absl/strings/string_view.h"
 
 namespace testutil = firebase::firestore::testutil;
 namespace util = firebase::firestore::util;
@@ -41,16 +41,14 @@ NS_ASSUME_NONNULL_BEGIN
 
 /** Convenience methods for building test queries. */
 @interface FSTQuery (Tests)
-- (FSTQuery *)queryByAddingSortBy:(NSString *)key ascending:(BOOL)ascending;
+- (FSTQuery *)queryByAddingSortBy:(const absl::string_view)key ascending:(BOOL)ascending;
 @end
 
 @implementation FSTQuery (Tests)
 
-- (FSTQuery *)queryByAddingSortBy:(NSString *)key ascending:(BOOL)ascending {
-  return [self
-      queryByAddingSortOrder:[FSTSortOrder
-                                 sortOrderWithFieldPath:testutil::Field(util::MakeStringView(key))
-                                              ascending:ascending]];
+- (FSTQuery *)queryByAddingSortBy:(const absl::string_view)key ascending:(BOOL)ascending {
+  return [self queryByAddingSortOrder:[FSTSortOrder sortOrderWithFieldPath:testutil::Field(key)
+                                                                 ascending:ascending]];
 }
 
 @end
@@ -61,9 +59,8 @@ NS_ASSUME_NONNULL_BEGIN
 @implementation FSTQueryTests
 
 - (void)testConstructor {
-  FSTResourcePath *path =
-      [FSTResourcePath pathWithSegments:@[ @"rooms", @"Firestore", @"messages", @"0001" ]];
-  FSTQuery *query = [FSTQuery queryWithPath:[path toCPPResourcePath]];
+  const ResourcePath path{"rooms", "Firestore", "messages", "0001"};
+  FSTQuery *query = [FSTQuery queryWithPath:path];
   XCTAssertNotNil(query);
 
   XCTAssertEqual(query.sortOrders.count, 1);
@@ -74,7 +71,7 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testOrderBy {
-  FSTQuery *query = FSTTestQuery(@"rooms/Firestore/messages");
+  FSTQuery *query = FSTTestQuery("rooms/Firestore/messages");
   query =
       [query queryByAddingSortOrder:[FSTSortOrder sortOrderWithFieldPath:testutil::Field("length")
                                                                ascending:NO]];
@@ -96,7 +93,7 @@ NS_ASSUME_NONNULL_BEGIN
   FSTDocument *doc3 = FSTTestDoc(@"rooms/other/messages/1", 0, @{@"text" : @"msg3"}, NO);
 
   // document query
-  FSTQuery *query = FSTTestQuery(@"rooms/eros/messages/1");
+  FSTQuery *query = FSTTestQuery("rooms/eros/messages/1");
   XCTAssertTrue([query matchesDocument:doc1]);
   XCTAssertFalse([query matchesDocument:doc2]);
   XCTAssertFalse([query matchesDocument:doc3]);
@@ -109,7 +106,7 @@ NS_ASSUME_NONNULL_BEGIN
   FSTDocument *doc3 = FSTTestDoc(@"rooms/other/messages/1", 0, @{@"text" : @"msg3"}, NO);
 
   // shallow ancestor query
-  FSTQuery *query = FSTTestQuery(@"rooms/eros/messages");
+  FSTQuery *query = FSTTestQuery("rooms/eros/messages");
   XCTAssertTrue([query matchesDocument:doc1]);
   XCTAssertFalse([query matchesDocument:doc1Meta]);
   XCTAssertTrue([query matchesDocument:doc2]);
@@ -120,17 +117,17 @@ NS_ASSUME_NONNULL_BEGIN
   FSTDocument *doc1 = FSTTestDoc(@"rooms/eros/messages/1", 0, @{@"text" : @"msg1"}, NO);
   FSTDocument *doc2 = FSTTestDoc(@"rooms/eros/messages/2", 0, @{}, NO);
 
-  FSTQuery *query = [FSTTestQuery(@"rooms/eros/messages")
-      queryByAddingFilter:FSTTestFilter(@"text", @"==", @"msg1")];
+  FSTQuery *query = [FSTTestQuery("rooms/eros/messages")
+      queryByAddingFilter:FSTTestFilter("text", @"==", @"msg1")];
   XCTAssertTrue([query matchesDocument:doc1]);
   XCTAssertFalse([query matchesDocument:doc2]);
 }
 
 - (void)testMatchesPrimitiveValuesForFilters {
   FSTQuery *query1 =
-      [FSTTestQuery(@"collection") queryByAddingFilter:FSTTestFilter(@"sort", @">=", @(2))];
+      [FSTTestQuery("collection") queryByAddingFilter:FSTTestFilter("sort", @">=", @(2))];
   FSTQuery *query2 =
-      [FSTTestQuery(@"collection") queryByAddingFilter:FSTTestFilter(@"sort", @"<=", @(2))];
+      [FSTTestQuery("collection") queryByAddingFilter:FSTTestFilter("sort", @"<=", @(2))];
 
   FSTDocument *doc1 = FSTTestDoc(@"collection/1", 0, @{ @"sort" : @1 }, NO);
   FSTDocument *doc2 = FSTTestDoc(@"collection/2", 0, @{ @"sort" : @2 }, NO);
@@ -155,8 +152,8 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testNullFilter {
-  FSTQuery *query = [FSTTestQuery(@"collection")
-      queryByAddingFilter:FSTTestFilter(@"sort", @"==", [NSNull null])];
+  FSTQuery *query =
+      [FSTTestQuery("collection") queryByAddingFilter:FSTTestFilter("sort", @"==", [NSNull null])];
   FSTDocument *doc1 = FSTTestDoc(@"collection/1", 0, @{@"sort" : [NSNull null]}, NO);
   FSTDocument *doc2 = FSTTestDoc(@"collection/2", 0, @{ @"sort" : @2 }, NO);
   FSTDocument *doc3 = FSTTestDoc(@"collection/2", 0, @{ @"sort" : @3.1 }, NO);
@@ -172,7 +169,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)testNanFilter {
   FSTQuery *query =
-      [FSTTestQuery(@"collection") queryByAddingFilter:FSTTestFilter(@"sort", @"==", @(NAN))];
+      [FSTTestQuery("collection") queryByAddingFilter:FSTTestFilter("sort", @"==", @(NAN))];
   FSTDocument *doc1 = FSTTestDoc(@"collection/1", 0, @{ @"sort" : @(NAN) }, NO);
   FSTDocument *doc2 = FSTTestDoc(@"collection/2", 0, @{ @"sort" : @2 }, NO);
   FSTDocument *doc3 = FSTTestDoc(@"collection/2", 0, @{ @"sort" : @3.1 }, NO);
@@ -188,9 +185,9 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)testDoesNotMatchComplexObjectsForFilters {
   FSTQuery *query1 =
-      [FSTTestQuery(@"collection") queryByAddingFilter:FSTTestFilter(@"sort", @"<=", @(2))];
+      [FSTTestQuery("collection") queryByAddingFilter:FSTTestFilter("sort", @"<=", @(2))];
   FSTQuery *query2 =
-      [FSTTestQuery(@"collection") queryByAddingFilter:FSTTestFilter(@"sort", @">=", @(2))];
+      [FSTTestQuery("collection") queryByAddingFilter:FSTTestFilter("sort", @">=", @(2))];
 
   FSTDocument *doc1 = FSTTestDoc(@"collection/1", 0, @{ @"sort" : @2 }, NO);
   FSTDocument *doc2 = FSTTestDoc(@"collection/2", 0, @{ @"sort" : @[] }, NO);
@@ -218,7 +215,7 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testDoesntRemoveComplexObjectsWithOrderBy {
-  FSTQuery *query1 = [FSTTestQuery(@"collection")
+  FSTQuery *query1 = [FSTTestQuery("collection")
       queryByAddingSortOrder:[FSTSortOrder sortOrderWithFieldPath:testutil::Field("sort")
                                                         ascending:YES]];
 
@@ -238,16 +235,16 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testFiltersBasedOnArrayValue {
-  FSTQuery *baseQuery = FSTTestQuery(@"collection");
+  FSTQuery *baseQuery = FSTTestQuery("collection");
   FSTDocument *doc1 = FSTTestDoc(@"collection/doc", 0, @{ @"tags" : @[ @"foo", @1, @YES ] }, NO);
 
   NSArray<id<FSTFilter>> *matchingFilters =
-      @[ FSTTestFilter(@"tags", @"==", @[ @"foo", @1, @YES ]) ];
+      @[ FSTTestFilter("tags", @"==", @[ @"foo", @1, @YES ]) ];
 
   NSArray<id<FSTFilter>> *nonMatchingFilters = @[
-    FSTTestFilter(@"tags", @"==", @"foo"),
-    FSTTestFilter(@"tags", @"==", @[ @"foo", @1 ]),
-    FSTTestFilter(@"tags", @"==", @[ @"foo", @YES, @1 ]),
+    FSTTestFilter("tags", @"==", @"foo"),
+    FSTTestFilter("tags", @"==", @[ @"foo", @1 ]),
+    FSTTestFilter("tags", @"==", @[ @"foo", @YES, @1 ]),
   ];
 
   for (id<FSTFilter> filter in matchingFilters) {
@@ -260,27 +257,27 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testFiltersBasedOnObjectValue {
-  FSTQuery *baseQuery = FSTTestQuery(@"collection");
+  FSTQuery *baseQuery = FSTTestQuery("collection");
   FSTDocument *doc1 =
       FSTTestDoc(@"collection/doc", 0,
                  @{ @"tags" : @{@"foo" : @"foo", @"a" : @0, @"b" : @YES, @"c" : @(NAN)} }, NO);
 
   NSArray<id<FSTFilter>> *matchingFilters = @[
-    FSTTestFilter(@"tags", @"==",
+    FSTTestFilter("tags", @"==",
                   @{ @"foo" : @"foo",
                      @"a" : @0,
                      @"b" : @YES,
                      @"c" : @(NAN) }),
-    FSTTestFilter(@"tags", @"==",
+    FSTTestFilter("tags", @"==",
                   @{ @"b" : @YES,
                      @"a" : @0,
                      @"foo" : @"foo",
                      @"c" : @(NAN) }),
-    FSTTestFilter(@"tags.foo", @"==", @"foo")
+    FSTTestFilter("tags.foo", @"==", @"foo")
   ];
 
   NSArray<id<FSTFilter>> *nonMatchingFilters = @[
-    FSTTestFilter(@"tags", @"==", @"foo"), FSTTestFilter(@"tags", @"==", @{
+    FSTTestFilter("tags", @"==", @"foo"), FSTTestFilter("tags", @"==", @{
       @"foo" : @"foo",
       @"a" : @0,
       @"b" : @YES,
@@ -312,7 +309,7 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testSortsDocumentsInTheCorrectOrder {
-  FSTQuery *query = FSTTestQuery(@"collection");
+  FSTQuery *query = FSTTestQuery("collection");
   query = [query queryByAddingSortOrder:[FSTSortOrder sortOrderWithFieldPath:testutil::Field("sort")
                                                                    ascending:YES]];
 
@@ -340,7 +337,7 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testSortsDocumentsUsingMultipleFields {
-  FSTQuery *query = FSTTestQuery(@"collection");
+  FSTQuery *query = FSTTestQuery("collection");
   query =
       [query queryByAddingSortOrder:[FSTSortOrder sortOrderWithFieldPath:testutil::Field("sort1")
                                                                ascending:YES]];
@@ -367,7 +364,7 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testSortsDocumentsWithDescendingToo {
-  FSTQuery *query = FSTTestQuery(@"collection");
+  FSTQuery *query = FSTTestQuery("collection");
   query =
       [query queryByAddingSortOrder:[FSTSortOrder sortOrderWithFieldPath:testutil::Field("sort1")
                                                                ascending:NO]];
@@ -394,40 +391,40 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testEquality {
-  FSTQuery *q11 = FSTTestQuery(@"foo");
-  q11 = [q11 queryByAddingFilter:FSTTestFilter(@"i1", @"<", @(2))];
-  q11 = [q11 queryByAddingFilter:FSTTestFilter(@"i2", @"==", @(3))];
-  FSTQuery *q12 = FSTTestQuery(@"foo");
-  q12 = [q12 queryByAddingFilter:FSTTestFilter(@"i2", @"==", @(3))];
-  q12 = [q12 queryByAddingFilter:FSTTestFilter(@"i1", @"<", @(2))];
-
-  FSTQuery *q21 = FSTTestQuery(@"foo");
-  FSTQuery *q22 = FSTTestQuery(@"foo");
-
-  FSTQuery *q31 = FSTTestQuery(@"foo/bar");
-  FSTQuery *q32 = FSTTestQuery(@"foo/bar");
-
-  FSTQuery *q41 = FSTTestQuery(@"foo");
-  q41 = [q41 queryByAddingSortBy:@"foo" ascending:YES];
-  q41 = [q41 queryByAddingSortBy:@"bar" ascending:YES];
-  FSTQuery *q42 = FSTTestQuery(@"foo");
-  q42 = [q42 queryByAddingSortBy:@"foo" ascending:YES];
-  q42 = [q42 queryByAddingSortBy:@"bar" ascending:YES];
-  FSTQuery *q43Diff = FSTTestQuery(@"foo");
-  q43Diff = [q43Diff queryByAddingSortBy:@"bar" ascending:YES];
-  q43Diff = [q43Diff queryByAddingSortBy:@"foo" ascending:YES];
-
-  FSTQuery *q51 = FSTTestQuery(@"foo");
-  q51 = [q51 queryByAddingSortBy:@"foo" ascending:YES];
-  q51 = [q51 queryByAddingFilter:FSTTestFilter(@"foo", @">", @(2))];
-  FSTQuery *q52 = FSTTestQuery(@"foo");
-  q52 = [q52 queryByAddingFilter:FSTTestFilter(@"foo", @">", @(2))];
-  q52 = [q52 queryByAddingSortBy:@"foo" ascending:YES];
-  FSTQuery *q53Diff = FSTTestQuery(@"foo");
-  q53Diff = [q53Diff queryByAddingFilter:FSTTestFilter(@"bar", @">", @(2))];
-  q53Diff = [q53Diff queryByAddingSortBy:@"bar" ascending:YES];
-
-  FSTQuery *q61 = FSTTestQuery(@"foo");
+  FSTQuery *q11 = FSTTestQuery("foo");
+  q11 = [q11 queryByAddingFilter:FSTTestFilter("i1", @"<", @(2))];
+  q11 = [q11 queryByAddingFilter:FSTTestFilter("i2", @"==", @(3))];
+  FSTQuery *q12 = FSTTestQuery("foo");
+  q12 = [q12 queryByAddingFilter:FSTTestFilter("i2", @"==", @(3))];
+  q12 = [q12 queryByAddingFilter:FSTTestFilter("i1", @"<", @(2))];
+
+  FSTQuery *q21 = FSTTestQuery("foo");
+  FSTQuery *q22 = FSTTestQuery("foo");
+
+  FSTQuery *q31 = FSTTestQuery("foo/bar");
+  FSTQuery *q32 = FSTTestQuery("foo/bar");
+
+  FSTQuery *q41 = FSTTestQuery("foo");
+  q41 = [q41 queryByAddingSortBy:"foo" ascending:YES];
+  q41 = [q41 queryByAddingSortBy:"bar" ascending:YES];
+  FSTQuery *q42 = FSTTestQuery("foo");
+  q42 = [q42 queryByAddingSortBy:"foo" ascending:YES];
+  q42 = [q42 queryByAddingSortBy:"bar" ascending:YES];
+  FSTQuery *q43Diff = FSTTestQuery("foo");
+  q43Diff = [q43Diff queryByAddingSortBy:"bar" ascending:YES];
+  q43Diff = [q43Diff queryByAddingSortBy:"foo" ascending:YES];
+
+  FSTQuery *q51 = FSTTestQuery("foo");
+  q51 = [q51 queryByAddingSortBy:"foo" ascending:YES];
+  q51 = [q51 queryByAddingFilter:FSTTestFilter("foo", @">", @(2))];
+  FSTQuery *q52 = FSTTestQuery("foo");
+  q52 = [q52 queryByAddingFilter:FSTTestFilter("foo", @">", @(2))];
+  q52 = [q52 queryByAddingSortBy:"foo" ascending:YES];
+  FSTQuery *q53Diff = FSTTestQuery("foo");
+  q53Diff = [q53Diff queryByAddingFilter:FSTTestFilter("bar", @">", @(2))];
+  q53Diff = [q53Diff queryByAddingSortBy:"bar" ascending:YES];
+
+  FSTQuery *q61 = FSTTestQuery("foo");
   q61 = [q61 queryBySettingLimit:10];
 
   // XCTAssertEqualObjects(q11, q12);  // TODO(klimt): not canonical yet
@@ -459,40 +456,40 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testUniqueIds {
-  FSTQuery *q11 = FSTTestQuery(@"foo");
-  q11 = [q11 queryByAddingFilter:FSTTestFilter(@"i1", @"<", @(2))];
-  q11 = [q11 queryByAddingFilter:FSTTestFilter(@"i2", @"==", @(3))];
-  FSTQuery *q12 = FSTTestQuery(@"foo");
-  q12 = [q12 queryByAddingFilter:FSTTestFilter(@"i2", @"==", @(3))];
-  q12 = [q12 queryByAddingFilter:FSTTestFilter(@"i1", @"<", @(2))];
-
-  FSTQuery *q21 = FSTTestQuery(@"foo");
-  FSTQuery *q22 = FSTTestQuery(@"foo");
-
-  FSTQuery *q31 = FSTTestQuery(@"foo/bar");
-  FSTQuery *q32 = FSTTestQuery(@"foo/bar");
-
-  FSTQuery *q41 = FSTTestQuery(@"foo");
-  q41 = [q41 queryByAddingSortBy:@"foo" ascending:YES];
-  q41 = [q41 queryByAddingSortBy:@"bar" ascending:YES];
-  FSTQuery *q42 = FSTTestQuery(@"foo");
-  q42 = [q42 queryByAddingSortBy:@"foo" ascending:YES];
-  q42 = [q42 queryByAddingSortBy:@"bar" ascending:YES];
-  FSTQuery *q43Diff = FSTTestQuery(@"foo");
-  q43Diff = [q43Diff queryByAddingSortBy:@"bar" ascending:YES];
-  q43Diff = [q43Diff queryByAddingSortBy:@"foo" ascending:YES];
-
-  FSTQuery *q51 = FSTTestQuery(@"foo");
-  q51 = [q51 queryByAddingSortBy:@"foo" ascending:YES];
-  q51 = [q51 queryByAddingFilter:FSTTestFilter(@"foo", @">", @(2))];
-  FSTQuery *q52 = FSTTestQuery(@"foo");
-  q52 = [q52 queryByAddingFilter:FSTTestFilter(@"foo", @">", @(2))];
-  q52 = [q52 queryByAddingSortBy:@"foo" ascending:YES];
-  FSTQuery *q53Diff = FSTTestQuery(@"foo");
-  q53Diff = [q53Diff queryByAddingFilter:FSTTestFilter(@"bar", @">", @(2))];
-  q53Diff = [q53Diff queryByAddingSortBy:@"bar" ascending:YES];
-
-  FSTQuery *q61 = FSTTestQuery(@"foo");
+  FSTQuery *q11 = FSTTestQuery("foo");
+  q11 = [q11 queryByAddingFilter:FSTTestFilter("i1", @"<", @(2))];
+  q11 = [q11 queryByAddingFilter:FSTTestFilter("i2", @"==", @(3))];
+  FSTQuery *q12 = FSTTestQuery("foo");
+  q12 = [q12 queryByAddingFilter:FSTTestFilter("i2", @"==", @(3))];
+  q12 = [q12 queryByAddingFilter:FSTTestFilter("i1", @"<", @(2))];
+
+  FSTQuery *q21 = FSTTestQuery("foo");
+  FSTQuery *q22 = FSTTestQuery("foo");
+
+  FSTQuery *q31 = FSTTestQuery("foo/bar");
+  FSTQuery *q32 = FSTTestQuery("foo/bar");
+
+  FSTQuery *q41 = FSTTestQuery("foo");
+  q41 = [q41 queryByAddingSortBy:"foo" ascending:YES];
+  q41 = [q41 queryByAddingSortBy:"bar" ascending:YES];
+  FSTQuery *q42 = FSTTestQuery("foo");
+  q42 = [q42 queryByAddingSortBy:"foo" ascending:YES];
+  q42 = [q42 queryByAddingSortBy:"bar" ascending:YES];
+  FSTQuery *q43Diff = FSTTestQuery("foo");
+  q43Diff = [q43Diff queryByAddingSortBy:"bar" ascending:YES];
+  q43Diff = [q43Diff queryByAddingSortBy:"foo" ascending:YES];
+
+  FSTQuery *q51 = FSTTestQuery("foo");
+  q51 = [q51 queryByAddingSortBy:"foo" ascending:YES];
+  q51 = [q51 queryByAddingFilter:FSTTestFilter("foo", @">", @(2))];
+  FSTQuery *q52 = FSTTestQuery("foo");
+  q52 = [q52 queryByAddingFilter:FSTTestFilter("foo", @">", @(2))];
+  q52 = [q52 queryByAddingSortBy:"foo" ascending:YES];
+  FSTQuery *q53Diff = FSTTestQuery("foo");
+  q53Diff = [q53Diff queryByAddingFilter:FSTTestFilter("bar", @">", @(2))];
+  q53Diff = [q53Diff queryByAddingSortBy:"bar" ascending:YES];
+
+  FSTQuery *q61 = FSTTestQuery("foo");
   q61 = [q61 queryBySettingLimit:10];
 
   // XCTAssertEqual(q11.hash, q12.hash);  // TODO(klimt): not canonical yet
@@ -524,52 +521,55 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testImplicitOrderBy {
-  FSTQuery *baseQuery = FSTTestQuery(@"foo");
+  FSTQuery *baseQuery = FSTTestQuery("foo");
   // Default is ascending
-  XCTAssertEqualObjects(baseQuery.sortOrders, @[ FSTTestOrderBy(kDocumentKeyPath, @"asc") ]);
+  XCTAssertEqualObjects(baseQuery.sortOrders,
+                        @[ FSTTestOrderBy(FieldPath::kDocumentKeyPath, @"asc") ]);
 
   // Explicit key ordering is respected
   XCTAssertEqualObjects(
-      [baseQuery queryByAddingSortOrder:FSTTestOrderBy(kDocumentKeyPath, @"asc")].sortOrders,
-      @[ FSTTestOrderBy(kDocumentKeyPath, @"asc") ]);
+      [baseQuery queryByAddingSortOrder:FSTTestOrderBy(FieldPath::kDocumentKeyPath, @"asc")]
+          .sortOrders,
+      @[ FSTTestOrderBy(FieldPath::kDocumentKeyPath, @"asc") ]);
   XCTAssertEqualObjects(
-      [baseQuery queryByAddingSortOrder:FSTTestOrderBy(kDocumentKeyPath, @"desc")].sortOrders,
-      @[ FSTTestOrderBy(kDocumentKeyPath, @"desc") ]);
+      [baseQuery queryByAddingSortOrder:FSTTestOrderBy(FieldPath::kDocumentKeyPath, @"desc")]
+          .sortOrders,
+      @[ FSTTestOrderBy(FieldPath::kDocumentKeyPath, @"desc") ]);
 
   XCTAssertEqualObjects(
-      [[baseQuery queryByAddingSortOrder:FSTTestOrderBy(@"foo", @"asc")]
-          queryByAddingSortOrder:FSTTestOrderBy(kDocumentKeyPath, @"asc")]
+      [[baseQuery queryByAddingSortOrder:FSTTestOrderBy("foo", @"asc")]
+          queryByAddingSortOrder:FSTTestOrderBy(FieldPath::kDocumentKeyPath, @"asc")]
           .sortOrders,
-      (@[ FSTTestOrderBy(@"foo", @"asc"), FSTTestOrderBy(kDocumentKeyPath, @"asc") ]));
+      (@[ FSTTestOrderBy("foo", @"asc"), FSTTestOrderBy(FieldPath::kDocumentKeyPath, @"asc") ]));
 
   XCTAssertEqualObjects(
-      [[baseQuery queryByAddingSortOrder:FSTTestOrderBy(@"foo", @"asc")]
-          queryByAddingSortOrder:FSTTestOrderBy(kDocumentKeyPath, @"desc")]
+      [[baseQuery queryByAddingSortOrder:FSTTestOrderBy("foo", @"asc")]
+          queryByAddingSortOrder:FSTTestOrderBy(FieldPath::kDocumentKeyPath, @"desc")]
           .sortOrders,
-      (@[ FSTTestOrderBy(@"foo", @"asc"), FSTTestOrderBy(kDocumentKeyPath, @"desc") ]));
+      (@[ FSTTestOrderBy("foo", @"asc"), FSTTestOrderBy(FieldPath::kDocumentKeyPath, @"desc") ]));
 
   // Inequality filters add order bys
   XCTAssertEqualObjects(
-      [baseQuery queryByAddingFilter:FSTTestFilter(@"foo", @"<", @5)].sortOrders,
-      (@[ FSTTestOrderBy(@"foo", @"asc"), FSTTestOrderBy(kDocumentKeyPath, @"asc") ]));
+      [baseQuery queryByAddingFilter:FSTTestFilter("foo", @"<", @5)].sortOrders,
+      (@[ FSTTestOrderBy("foo", @"asc"), FSTTestOrderBy(FieldPath::kDocumentKeyPath, @"asc") ]));
 
   // Descending order by applies to implicit key ordering
   XCTAssertEqualObjects(
-      [baseQuery queryByAddingSortOrder:FSTTestOrderBy(@"foo", @"desc")].sortOrders,
-      (@[ FSTTestOrderBy(@"foo", @"desc"), FSTTestOrderBy(kDocumentKeyPath, @"desc") ]));
-  XCTAssertEqualObjects([[baseQuery queryByAddingSortOrder:FSTTestOrderBy(@"foo", @"asc")]
-                            queryByAddingSortOrder:FSTTestOrderBy(@"bar", @"desc")]
+      [baseQuery queryByAddingSortOrder:FSTTestOrderBy("foo", @"desc")].sortOrders,
+      (@[ FSTTestOrderBy("foo", @"desc"), FSTTestOrderBy(FieldPath::kDocumentKeyPath, @"desc") ]));
+  XCTAssertEqualObjects([[baseQuery queryByAddingSortOrder:FSTTestOrderBy("foo", @"asc")]
+                            queryByAddingSortOrder:FSTTestOrderBy("bar", @"desc")]
                             .sortOrders,
                         (@[
-                          FSTTestOrderBy(@"foo", @"asc"), FSTTestOrderBy(@"bar", @"desc"),
-                          FSTTestOrderBy(kDocumentKeyPath, @"desc")
+                          FSTTestOrderBy("foo", @"asc"), FSTTestOrderBy("bar", @"desc"),
+                          FSTTestOrderBy(FieldPath::kDocumentKeyPath, @"desc")
                         ]));
-  XCTAssertEqualObjects([[baseQuery queryByAddingSortOrder:FSTTestOrderBy(@"foo", @"desc")]
-                            queryByAddingSortOrder:FSTTestOrderBy(@"bar", @"asc")]
+  XCTAssertEqualObjects([[baseQuery queryByAddingSortOrder:FSTTestOrderBy("foo", @"desc")]
+                            queryByAddingSortOrder:FSTTestOrderBy("bar", @"asc")]
                             .sortOrders,
                         (@[
-                          FSTTestOrderBy(@"foo", @"desc"), FSTTestOrderBy(@"bar", @"asc"),
-                          FSTTestOrderBy(kDocumentKeyPath, @"asc")
+                          FSTTestOrderBy("foo", @"desc"), FSTTestOrderBy("bar", @"asc"),
+                          FSTTestOrderBy(FieldPath::kDocumentKeyPath, @"asc")
                         ]));
 }
 
diff --git a/Firestore/Example/Tests/Core/FSTViewSnapshotTest.mm b/Firestore/Example/Tests/Core/FSTViewSnapshotTest.mm
index fe3e42d..c503684 100644
--- a/Firestore/Example/Tests/Core/FSTViewSnapshotTest.mm
+++ b/Firestore/Example/Tests/Core/FSTViewSnapshotTest.mm
@@ -21,7 +21,6 @@
 #import "Firestore/Source/Core/FSTQuery.h"
 #import "Firestore/Source/Model/FSTDocument.h"
 #import "Firestore/Source/Model/FSTDocumentSet.h"
-#import "Firestore/Source/Model/FSTPath.h"
 
 #import "Firestore/Example/Tests/Util/FSTHelpers.h"
 
@@ -107,7 +106,7 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testViewSnapshotConstructor {
-  FSTQuery *query = FSTTestQuery(@"a");
+  FSTQuery *query = FSTTestQuery("a");
   FSTDocumentSet *documents = [FSTDocumentSet documentSetWithComparator:FSTDocumentComparatorByKey];
   FSTDocumentSet *oldDocuments = documents;
   documents = [documents documentSetByAddingDocument:FSTTestDoc(@"c/a", 1, @{}, NO)];
diff --git a/Firestore/Example/Tests/Core/FSTViewTests.mm b/Firestore/Example/Tests/Core/FSTViewTests.mm
index 7df8195..1e3ec1a 100644
--- a/Firestore/Example/Tests/Core/FSTViewTests.mm
+++ b/Firestore/Example/Tests/Core/FSTViewTests.mm
@@ -25,7 +25,6 @@
 #import "Firestore/Source/Model/FSTDocumentKey.h"
 #import "Firestore/Source/Model/FSTDocumentSet.h"
 #import "Firestore/Source/Model/FSTFieldValue.h"
-#import "Firestore/Source/Model/FSTPath.h"
 #import "Firestore/Source/Remote/FSTRemoteEvent.h"
 
 #import "Firestore/Example/Tests/Util/FSTHelpers.h"