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

2 files changed, 67 insertions, 66 deletions

diff --git a/Firestore/Example/Tests/Util/FSTHelpers.h b/Firestore/Example/Tests/Util/FSTHelpers.h
index cc9f2ec..d86201b 100644
--- a/Firestore/Example/Tests/Util/FSTHelpers.h
+++ b/Firestore/Example/Tests/Util/FSTHelpers.h
@@ -16,10 +16,16 @@
 
 #import <Foundation/Foundation.h>
 
+#include <map>
+#include <vector>
+
 #import "Firestore/Source/Core/FSTTypes.h"
 #import "Firestore/Source/Model/FSTDocumentDictionary.h"
 #import "Firestore/Source/Model/FSTDocumentKeySet.h"
 
+#include "Firestore/core/src/firebase/firestore/model/field_path.h"
+#include "Firestore/core/src/firebase/firestore/model/field_value.h"
+#include "Firestore/core/src/firebase/firestore/model/resource_path.h"
 #include "absl/strings/string_view.h"
 
 @class FIRGeoPoint;
@@ -28,13 +34,11 @@
 @class FSTDocument;
 @class FSTDocumentKeyReference;
 @class FSTDocumentSet;
-@class FSTFieldPath;
 @class FSTFieldValue;
 @class FSTLocalViewChanges;
 @class FSTPatchMutation;
 @class FSTQuery;
 @class FSTRemoteEvent;
-@class FSTResourcePath;
 @class FSTSetMutation;
 @class FSTSnapshotVersion;
 @class FSTSortOrder;
@@ -121,18 +125,30 @@ extern "C" {
     }                                                                                            \
   } while (0)
 
+static NSString *kExceptionPrefix = @"FIRESTORE INTERNAL ASSERTION FAILED: ";
+
+// Remove possible exception-prefix.
+inline NSString *FSTRemoveExceptionPrefix(NSString *exception) {
+  if ([exception hasPrefix:kExceptionPrefix]) {
+    return [exception substringFromIndex:kExceptionPrefix.length];
+  } else {
+    return exception;
+  }
+}
+
 // Helper for validating API exceptions.
-#define FSTAssertThrows(expression, exceptionReason, ...)       \
-  ({                                                            \
-    BOOL __didThrow = NO;                                       \
-    @try {                                                      \
-      (void)(expression);                                       \
-    } @catch (NSException * exception) {                        \
-      __didThrow = YES;                                         \
-      XCTAssertEqualObjects(exception.reason, exceptionReason); \
-    }                                                           \
-    XCTAssertTrue(__didThrow, ##__VA_ARGS__);                   \
-  })
+#define FSTAssertThrows(expression, exceptionReason, ...)               \
+  do {                                                                  \
+    BOOL didThrow = NO;                                                 \
+    @try {                                                              \
+      (void)(expression);                                               \
+    } @catch (NSException * exception) {                                \
+      didThrow = YES;                                                   \
+      XCTAssertEqualObjects(FSTRemoveExceptionPrefix(exception.reason), \
+                            FSTRemoveExceptionPrefix(exceptionReason)); \
+    }                                                                   \
+    XCTAssertTrue(didThrow, ##__VA_ARGS__);                             \
+  } while (0)
 
 /** Creates a new FIRTimestamp from components. Note that year, month, and day are all one-based. */
 FIRTimestamp *FSTTestTimestamp(int year, int month, int day, int hour, int minute, int second);
@@ -157,8 +173,6 @@ FIRGeoPoint *FSTTestGeoPoint(double latitude, double longitude);
 NSDateComponents *FSTTestDateComponents(
     int year, int month, int day, int hour, int minute, int second);
 
-FSTFieldPath *FSTTestFieldPath(NSString *field);
-
 /** Wraps a plain value into an FSTFieldValue instance. */
 FSTFieldValue *FSTTestFieldValue(id _Nullable value);
 
@@ -186,9 +200,6 @@ FSTDocument *FSTTestDoc(NSString *path,
 /** A convenience method for creating deleted docs for tests. */
 FSTDeletedDocument *FSTTestDeletedDoc(NSString *path, FSTTestSnapshotVersion version);
 
-/** A convenience method for creating resource paths from a path string. */
-FSTResourcePath *FSTTestPath(NSString *path);
-
 /**
  * A convenience method for creating a document reference from a path string.
  */
@@ -197,22 +208,22 @@ FSTDocumentKeyReference *FSTTestRef(const absl::string_view projectID,
                                     NSString *path);
 
 /** A convenience method for creating a query for the given path (without any other filters). */
-FSTQuery *FSTTestQuery(NSString *path);
+FSTQuery *FSTTestQuery(const absl::string_view path);
 
 /**
  * A convenience method to create a FSTFilter using a string representation for both field
  * and operator (<, <=, ==, >=, >).
  */
-id<FSTFilter> FSTTestFilter(NSString *field, NSString *op, id value);
+id<FSTFilter> FSTTestFilter(const absl::string_view field, NSString *op, id value);
 
 /** A convenience method for creating sort orders. */
-FSTSortOrder *FSTTestOrderBy(NSString *field, NSString *direction);
+FSTSortOrder *FSTTestOrderBy(const absl::string_view field, NSString *direction);
 
 /**
  * Creates an NSComparator that will compare FSTDocuments by the given fieldPath string then by
  * key.
  */
-NSComparator FSTTestDocComparator(NSString *fieldPath);
+NSComparator FSTTestDocComparator(const absl::string_view fieldPath);
 
 /**
  * Creates a FSTDocumentSet based on the given comparator, initially containing the given
@@ -229,9 +240,10 @@ FSTViewSnapshot *_Nullable FSTTestApplyChanges(FSTView *view,
 FSTSetMutation *FSTTestSetMutation(NSString *path, NSDictionary<NSString *, id> *values);
 
 /** Creates a patch mutation for the document key at the given path. */
-FSTPatchMutation *FSTTestPatchMutation(NSString *path,
-                                       NSDictionary<NSString *, id> *values,
-                                       NSArray<FSTFieldPath *> *_Nullable updateMask);
+FSTPatchMutation *FSTTestPatchMutation(
+    const absl::string_view path,
+    NSDictionary<NSString *, id> *values,
+    const std::vector<firebase::firestore::model::FieldPath> &updateMask);
 
 FSTTransformMutation *FSTTestTransformMutation(NSString *path,
                                                NSArray<NSString *> *serverTimestampFields);
diff --git a/Firestore/Example/Tests/Util/FSTHelpers.mm b/Firestore/Example/Tests/Util/FSTHelpers.mm
index 00464bc..be02002 100644
--- a/Firestore/Example/Tests/Util/FSTHelpers.mm
+++ b/Firestore/Example/Tests/Util/FSTHelpers.mm
@@ -18,6 +18,8 @@
 
 #include <inttypes.h>
 #include <list>
+#include <map>
+#include <vector>
 
 #import <FirebaseFirestore/FIRFieldPath.h>
 #import <FirebaseFirestore/FIRGeoPoint.h>
@@ -36,18 +38,22 @@
 #import "Firestore/Source/Model/FSTDocumentSet.h"
 #import "Firestore/Source/Model/FSTFieldValue.h"
 #import "Firestore/Source/Model/FSTMutation.h"
-#import "Firestore/Source/Model/FSTPath.h"
 #import "Firestore/Source/Remote/FSTRemoteEvent.h"
 #import "Firestore/Source/Remote/FSTWatchChange.h"
 #import "Firestore/Source/Util/FSTAssert.h"
 
 #include "Firestore/core/src/firebase/firestore/model/database_id.h"
+#include "Firestore/core/src/firebase/firestore/model/field_value.h"
+#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"
 
 namespace util = firebase::firestore::util;
 namespace testutil = firebase::firestore::testutil;
 using firebase::firestore::model::DatabaseId;
+using firebase::firestore::model::FieldPath;
+using firebase::firestore::model::FieldValue;
+using firebase::firestore::model::ResourcePath;
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -103,10 +109,6 @@ NSDateComponents *FSTTestDateComponents(
   return comps;
 }
 
-FSTFieldPath *FSTTestFieldPath(NSString *field) {
-  return [FIRFieldPath pathWithDotSeparatedString:field].internalValue;
-}
-
 FSTFieldValue *FSTTestFieldValue(id _Nullable value) {
   // This owns the DatabaseIds since we do not have FirestoreClient instance to own them.
   static DatabaseId database_id{"project", DatabaseId::kDefault};
@@ -162,18 +164,6 @@ FSTDeletedDocument *FSTTestDeletedDoc(NSString *path, FSTTestSnapshotVersion ver
   return [FSTDeletedDocument documentWithKey:key version:FSTTestVersion(version)];
 }
 
-static NSArray<NSString *> *FSTTestSplitPath(NSString *path) {
-  if ([path isEqualToString:@""]) {
-    return @[];
-  } else {
-    return [path componentsSeparatedByString:@"/"];
-  }
-}
-
-FSTResourcePath *FSTTestPath(NSString *path) {
-  return [FSTResourcePath pathWithSegments:FSTTestSplitPath(path)];
-}
-
 FSTDocumentKeyReference *FSTTestRef(const absl::string_view projectID,
                                     const absl::string_view database,
                                     NSString *path) {
@@ -184,12 +174,12 @@ FSTDocumentKeyReference *FSTTestRef(const absl::string_view projectID,
                                            databaseID:&database_ids.back()];
 }
 
-FSTQuery *FSTTestQuery(NSString *path) {
-  return [FSTQuery queryWithPath:[FSTTestPath(path) toCPPResourcePath]];
+FSTQuery *FSTTestQuery(const absl::string_view path) {
+  return [FSTQuery queryWithPath:testutil::Resource(path)];
 }
 
-id<FSTFilter> FSTTestFilter(NSString *field, NSString *opString, id value) {
-  FSTFieldPath *path = FSTTestFieldPath(field);
+id<FSTFilter> FSTTestFilter(const absl::string_view field, NSString *opString, id value) {
+  const FieldPath path = testutil::Field(field);
   FSTRelationFilterOperator op;
   if ([opString isEqualToString:@"<"]) {
     op = FSTRelationFilterOperatorLessThan;
@@ -208,17 +198,17 @@ id<FSTFilter> FSTTestFilter(NSString *field, NSString *opString, id value) {
   FSTFieldValue *data = FSTTestFieldValue(value);
   if ([data isEqual:[FSTDoubleValue nanValue]]) {
     FSTCAssert(op == FSTRelationFilterOperatorEqual, @"Must use == with NAN.");
-    return [[FSTNanFilter alloc] initWithField:[path toCPPFieldPath]];
+    return [[FSTNanFilter alloc] initWithField:path];
   } else if ([data isEqual:[FSTNullValue nullValue]]) {
     FSTCAssert(op == FSTRelationFilterOperatorEqual, @"Must use == with Null.");
-    return [[FSTNullFilter alloc] initWithField:[path toCPPFieldPath]];
+    return [[FSTNullFilter alloc] initWithField:path];
   } else {
-    return [FSTRelationFilter filterWithField:[path toCPPFieldPath] filterOperator:op value:data];
+    return [FSTRelationFilter filterWithField:path filterOperator:op value:data];
   }
 }
 
-FSTSortOrder *FSTTestOrderBy(NSString *field, NSString *direction) {
-  FSTFieldPath *path = FSTTestFieldPath(field);
+FSTSortOrder *FSTTestOrderBy(const absl::string_view field, NSString *direction) {
+  const FieldPath path = testutil::Field(field);
   BOOL ascending;
   if ([direction isEqualToString:@"asc"]) {
     ascending = YES;
@@ -227,14 +217,13 @@ FSTSortOrder *FSTTestOrderBy(NSString *field, NSString *direction) {
   } else {
     FSTCFail(@"Unsupported direction: %@", direction);
   }
-  return [FSTSortOrder sortOrderWithFieldPath:[path toCPPFieldPath] ascending:ascending];
+  return [FSTSortOrder sortOrderWithFieldPath:path ascending:ascending];
 }
 
-NSComparator FSTTestDocComparator(NSString *fieldPath) {
-  FSTQuery *query = [FSTTestQuery(@"docs")
-      queryByAddingSortOrder:[FSTSortOrder
-                                 sortOrderWithFieldPath:[FSTTestFieldPath(fieldPath) toCPPFieldPath]
-                                              ascending:YES]];
+NSComparator FSTTestDocComparator(const absl::string_view fieldPath) {
+  FSTQuery *query = [FSTTestQuery("docs")
+      queryByAddingSortOrder:[FSTSortOrder sortOrderWithFieldPath:testutil::Field(fieldPath)
+                                                        ascending:YES]];
   return [query comparator];
 }
 
@@ -252,23 +241,23 @@ FSTSetMutation *FSTTestSetMutation(NSString *path, NSDictionary<NSString *, id>
                                 precondition:[FSTPrecondition none]];
 }
 
-FSTPatchMutation *FSTTestPatchMutation(NSString *path,
+FSTPatchMutation *FSTTestPatchMutation(const absl::string_view path,
                                        NSDictionary<NSString *, id> *values,
-                                       NSArray<FSTFieldPath *> *_Nullable updateMask) {
-  BOOL merge = updateMask != nil;
+                                       const std::vector<FieldPath> &updateMask) {
+  BOOL merge = !updateMask.empty();
 
   __block FSTObjectValue *objectValue = [FSTObjectValue objectValue];
-  NSMutableArray<FSTFieldPath *> *fieldMaskPaths = [NSMutableArray array];
+  __block std::vector<FieldPath> fieldMaskPaths{};
   [values enumerateKeysAndObjectsUsingBlock:^(NSString *key, id value, BOOL *stop) {
-    FSTFieldPath *path = FSTTestFieldPath(key);
-    [fieldMaskPaths addObject:path];
+    const FieldPath path = testutil::Field(util::MakeStringView(key));
+    fieldMaskPaths.push_back(path);
     if (![value isEqual:kDeleteSentinel]) {
       FSTFieldValue *parsedValue = FSTTestFieldValue(value);
       objectValue = [objectValue objectBySettingValue:parsedValue forPath:path];
     }
   }];
 
-  FSTDocumentKey *key = [FSTDocumentKey keyWithPath:testutil::Resource([path UTF8String])];
+  FSTDocumentKey *key = [FSTDocumentKey keyWithPath:testutil::Resource(path)];
   FSTFieldMask *mask = [[FSTFieldMask alloc] initWithFields:merge ? updateMask : fieldMaskPaths];
   return [[FSTPatchMutation alloc] initWithKey:key
                                      fieldMask:mask
@@ -279,10 +268,10 @@ FSTPatchMutation *FSTTestPatchMutation(NSString *path,
 // For now this only creates TransformMutations with server timestamps.
 FSTTransformMutation *FSTTestTransformMutation(NSString *path,
                                                NSArray<NSString *> *serverTimestampFields) {
-  FSTDocumentKey *key = [FSTDocumentKey keyWithPath:testutil::Resource([path UTF8String])];
+  FSTDocumentKey *key = [FSTDocumentKey keyWithPath:testutil::Resource(util::MakeStringView(path))];
   NSMutableArray<FSTFieldTransform *> *fieldTransforms = [NSMutableArray array];
   for (NSString *field in serverTimestampFields) {
-    FSTFieldPath *fieldPath = FSTTestFieldPath(field);
+    const FieldPath fieldPath = testutil::Field(util::MakeStringView(field));
     id<FSTTransformOperation> transformOp = [FSTServerTimestampTransform serverTimestampTransform];
     FSTFieldTransform *transform =
         [[FSTFieldTransform alloc] initWithPath:fieldPath transform:transformOp];