port `DocumentKey` to non-container types of `Model/*` (#930)

* 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

* add converter function between two DocumentKey implementations

* add unit test

* address changes

* fix lint

* using DocumentKey in model except for the container types `FSTDocumentDictionary`, `FSTDocumentKeySet`, and  `FSTDocumentVersionDictionary`

* change other place w.r.t. the use of `DocumentKey` in model

* update parameter of test helpers from NSString to string_view

* revert a temporary change used in debug

* address changes

3 files changed, 46 insertions, 44 deletions

diff --git a/Firestore/Example/Tests/Model/FSTDocumentSetTests.mm b/Firestore/Example/Tests/Model/FSTDocumentSetTests.mm
index d70c44d..65c4ddf 100644
--- a/Firestore/Example/Tests/Model/FSTDocumentSetTests.mm
+++ b/Firestore/Example/Tests/Model/FSTDocumentSetTests.mm
@@ -38,9 +38,9 @@ NS_ASSUME_NONNULL_BEGIN
   [super setUp];
 
   _comp = FSTTestDocComparator("sort");
-  _doc1 = FSTTestDoc(@"docs/1", 0, @{ @"sort" : @2 }, NO);
-  _doc2 = FSTTestDoc(@"docs/2", 0, @{ @"sort" : @3 }, NO);
-  _doc3 = FSTTestDoc(@"docs/3", 0, @{ @"sort" : @1 }, NO);
+  _doc1 = FSTTestDoc("docs/1", 0, @{ @"sort" : @2 }, NO);
+  _doc2 = FSTTestDoc("docs/2", 0, @{ @"sort" : @3 }, NO);
+  _doc3 = FSTTestDoc("docs/3", 0, @{ @"sort" : @1 }, NO);
 }
 
 - (void)testCount {
@@ -97,7 +97,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)testUpdates {
   FSTDocumentSet *set = FSTTestDocSet(_comp, @[ _doc1, _doc2, _doc3 ]);
 
-  FSTDocument *doc2Prime = FSTTestDoc(@"docs/2", 0, @{ @"sort" : @9 }, NO);
+  FSTDocument *doc2Prime = FSTTestDoc("docs/2", 0, @{ @"sort" : @9 }, NO);
 
   set = [set documentSetByAddingDocument:doc2Prime];
   XCTAssertEqual([set count], 3);
@@ -106,7 +106,7 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testAddsDocsWithEqualComparisonValues {
-  FSTDocument *doc4 = FSTTestDoc(@"docs/4", 0, @{ @"sort" : @2 }, NO);
+  FSTDocument *doc4 = FSTTestDoc("docs/4", 0, @{ @"sort" : @2 }, NO);
 
   FSTDocumentSet *set = FSTTestDocSet(_comp, @[ _doc1, doc4 ]);
   XCTAssertEqualObjects([[set documentEnumerator] allObjects], (@[ _doc1, doc4 ]));
diff --git a/Firestore/Example/Tests/Model/FSTDocumentTests.mm b/Firestore/Example/Tests/Model/FSTDocumentTests.mm
index 0527852..24858c5 100644
--- a/Firestore/Example/Tests/Model/FSTDocumentTests.mm
+++ b/Firestore/Example/Tests/Model/FSTDocumentTests.mm
@@ -19,14 +19,15 @@
 #import <XCTest/XCTest.h>
 
 #import "Firestore/Source/Core/FSTSnapshotVersion.h"
-#import "Firestore/Source/Model/FSTDocumentKey.h"
 #import "Firestore/Source/Model/FSTFieldValue.h"
 
 #import "Firestore/Example/Tests/Util/FSTHelpers.h"
 
+#include "Firestore/core/src/firebase/firestore/model/document_key.h"
 #include "Firestore/core/test/firebase/firestore/testutil/testutil.h"
 
 namespace testutil = firebase::firestore::testutil;
+using firebase::firestore::model::DocumentKey;
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -36,7 +37,7 @@ NS_ASSUME_NONNULL_BEGIN
 @implementation FSTDocumentTests
 
 - (void)testConstructor {
-  FSTDocumentKey *key = FSTTestDocKey(@"messages/first");
+  DocumentKey key = testutil::Key("messages/first");
   FSTSnapshotVersion *version = FSTTestVersion(1);
   FSTObjectValue *data = FSTTestObjectValue(@{ @"a" : @1 });
   FSTDocument *doc =
@@ -49,7 +50,7 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testExtractsFields {
-  FSTDocumentKey *key = FSTTestDocKey(@"rooms/eros");
+  DocumentKey key = testutil::Key("rooms/eros");
   FSTSnapshotVersion *version = FSTTestVersion(1);
   FSTObjectValue *data = FSTTestObjectValue(@{
     @"desc" : @"Discuss all the project related stuff",
@@ -65,30 +66,30 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (void)testIsEqual {
-  XCTAssertEqualObjects(FSTTestDoc(@"messages/first", 1,
+  XCTAssertEqualObjects(FSTTestDoc("messages/first", 1,
                                    @{ @"a" : @1 }, NO),
-                        FSTTestDoc(@"messages/first", 1,
+                        FSTTestDoc("messages/first", 1,
                                    @{ @"a" : @1 }, NO));
-  XCTAssertNotEqualObjects(FSTTestDoc(@"messages/first", 1,
+  XCTAssertNotEqualObjects(FSTTestDoc("messages/first", 1,
                                       @{ @"a" : @1 }, NO),
-                           FSTTestDoc(@"messages/first", 1,
+                           FSTTestDoc("messages/first", 1,
                                       @{ @"b" : @1 }, NO));
-  XCTAssertNotEqualObjects(FSTTestDoc(@"messages/first", 1,
+  XCTAssertNotEqualObjects(FSTTestDoc("messages/first", 1,
                                       @{ @"a" : @1 }, NO),
-                           FSTTestDoc(@"messages/second", 1,
+                           FSTTestDoc("messages/second", 1,
                                       @{ @"b" : @1 }, NO));
-  XCTAssertNotEqualObjects(FSTTestDoc(@"messages/first", 1,
+  XCTAssertNotEqualObjects(FSTTestDoc("messages/first", 1,
                                       @{ @"a" : @1 }, NO),
-                           FSTTestDoc(@"messages/first", 2,
+                           FSTTestDoc("messages/first", 2,
                                       @{ @"a" : @1 }, NO));
-  XCTAssertNotEqualObjects(FSTTestDoc(@"messages/first", 1,
+  XCTAssertNotEqualObjects(FSTTestDoc("messages/first", 1,
                                       @{ @"a" : @1 }, NO),
-                           FSTTestDoc(@"messages/first", 1,
+                           FSTTestDoc("messages/first", 1,
                                       @{ @"a" : @1 }, YES));
 
-  XCTAssertEqualObjects(FSTTestDoc(@"messages/first", 1,
+  XCTAssertEqualObjects(FSTTestDoc("messages/first", 1,
                                    @{ @"a" : @1 }, YES),
-                        FSTTestDoc(@"messages/first", 1,
+                        FSTTestDoc("messages/first", 1,
                                    @{ @"a" : @1 }, 5));
 }
 
diff --git a/Firestore/Example/Tests/Model/FSTMutationTests.mm b/Firestore/Example/Tests/Model/FSTMutationTests.mm
index 5b056fb..40ded40 100644
--- a/Firestore/Example/Tests/Model/FSTMutationTests.mm
+++ b/Firestore/Example/Tests/Model/FSTMutationTests.mm
@@ -20,14 +20,15 @@
 #import <XCTest/XCTest.h>
 
 #import "Firestore/Source/Model/FSTDocument.h"
-#import "Firestore/Source/Model/FSTDocumentKey.h"
 #import "Firestore/Source/Model/FSTFieldValue.h"
 
 #import "Firestore/Example/Tests/Util/FSTHelpers.h"
 
+#include "Firestore/core/src/firebase/firestore/model/document_key.h"
 #include "Firestore/core/test/firebase/firestore/testutil/testutil.h"
 
 namespace testutil = firebase::firestore::testutil;
+using firebase::firestore::model::DocumentKey;
 
 @interface FSTMutationTests : XCTestCase
 @end
@@ -42,32 +43,32 @@ namespace testutil = firebase::firestore::testutil;
 
 - (void)testAppliesSetsToDocuments {
   NSDictionary *docData = @{@"foo" : @"foo-value", @"baz" : @"baz-value"};
-  FSTDocument *baseDoc = FSTTestDoc(@"collection/key", 0, docData, NO);
+  FSTDocument *baseDoc = FSTTestDoc("collection/key", 0, docData, NO);
 
   FSTMutation *set = FSTTestSetMutation(@"collection/key", @{@"bar" : @"bar-value"});
   FSTMaybeDocument *setDoc = [set applyTo:baseDoc baseDocument:baseDoc localWriteTime:_timestamp];
 
   NSDictionary *expectedData = @{@"bar" : @"bar-value"};
-  XCTAssertEqualObjects(setDoc, FSTTestDoc(@"collection/key", 0, expectedData, YES));
+  XCTAssertEqualObjects(setDoc, FSTTestDoc("collection/key", 0, expectedData, YES));
 }
 
 - (void)testAppliesPatchesToDocuments {
   NSDictionary *docData = @{ @"foo" : @{@"bar" : @"bar-value"}, @"baz" : @"baz-value" };
-  FSTDocument *baseDoc = FSTTestDoc(@"collection/key", 0, docData, NO);
+  FSTDocument *baseDoc = FSTTestDoc("collection/key", 0, docData, NO);
 
   FSTMutation *patch = FSTTestPatchMutation("collection/key", @{@"foo.bar" : @"new-bar-value"}, {});
   FSTMaybeDocument *patchedDoc =
       [patch applyTo:baseDoc baseDocument:baseDoc localWriteTime:_timestamp];
 
   NSDictionary *expectedData = @{ @"foo" : @{@"bar" : @"new-bar-value"}, @"baz" : @"baz-value" };
-  XCTAssertEqualObjects(patchedDoc, FSTTestDoc(@"collection/key", 0, expectedData, YES));
+  XCTAssertEqualObjects(patchedDoc, FSTTestDoc("collection/key", 0, expectedData, YES));
 }
 
 - (void)testDeletesValuesFromTheFieldMask {
   NSDictionary *docData = @{ @"foo" : @{@"bar" : @"bar-value", @"baz" : @"baz-value"} };
-  FSTDocument *baseDoc = FSTTestDoc(@"collection/key", 0, docData, NO);
+  FSTDocument *baseDoc = FSTTestDoc("collection/key", 0, docData, NO);
 
-  FSTDocumentKey *key = FSTTestDocKey(@"collection/key");
+  DocumentKey key = testutil::Key("collection/key");
   FSTFieldMask *mask = [[FSTFieldMask alloc] initWithFields:{testutil::Field("foo.bar")}];
   FSTMutation *patch = [[FSTPatchMutation alloc] initWithKey:key
                                                    fieldMask:mask
@@ -77,23 +78,23 @@ namespace testutil = firebase::firestore::testutil;
       [patch applyTo:baseDoc baseDocument:baseDoc localWriteTime:_timestamp];
 
   NSDictionary *expectedData = @{ @"foo" : @{@"baz" : @"baz-value"} };
-  XCTAssertEqualObjects(patchedDoc, FSTTestDoc(@"collection/key", 0, expectedData, YES));
+  XCTAssertEqualObjects(patchedDoc, FSTTestDoc("collection/key", 0, expectedData, YES));
 }
 
 - (void)testPatchesPrimitiveValue {
   NSDictionary *docData = @{@"foo" : @"foo-value", @"baz" : @"baz-value"};
-  FSTDocument *baseDoc = FSTTestDoc(@"collection/key", 0, docData, NO);
+  FSTDocument *baseDoc = FSTTestDoc("collection/key", 0, docData, NO);
 
   FSTMutation *patch = FSTTestPatchMutation("collection/key", @{@"foo.bar" : @"new-bar-value"}, {});
   FSTMaybeDocument *patchedDoc =
       [patch applyTo:baseDoc baseDocument:baseDoc localWriteTime:_timestamp];
 
   NSDictionary *expectedData = @{ @"foo" : @{@"bar" : @"new-bar-value"}, @"baz" : @"baz-value" };
-  XCTAssertEqualObjects(patchedDoc, FSTTestDoc(@"collection/key", 0, expectedData, YES));
+  XCTAssertEqualObjects(patchedDoc, FSTTestDoc("collection/key", 0, expectedData, YES));
 }
 
 - (void)testPatchingDeletedDocumentsDoesNothing {
-  FSTMaybeDocument *baseDoc = FSTTestDeletedDoc(@"collection/key", 0);
+  FSTMaybeDocument *baseDoc = FSTTestDeletedDoc("collection/key", 0);
   FSTMutation *patch = FSTTestPatchMutation("collection/key", @{@"foo" : @"bar"}, {});
   FSTMaybeDocument *patchedDoc =
       [patch applyTo:baseDoc baseDocument:baseDoc localWriteTime:_timestamp];
@@ -102,7 +103,7 @@ namespace testutil = firebase::firestore::testutil;
 
 - (void)testAppliesLocalTransformsToDocuments {
   NSDictionary *docData = @{ @"foo" : @{@"bar" : @"bar-value"}, @"baz" : @"baz-value" };
-  FSTDocument *baseDoc = FSTTestDoc(@"collection/key", 0, docData, NO);
+  FSTDocument *baseDoc = FSTTestDoc("collection/key", 0, docData, NO);
 
   FSTMutation *transform = FSTTestTransformMutation(@"collection/key", @[ @"foo.bar" ]);
   FSTMaybeDocument *transformedDoc =
@@ -128,7 +129,7 @@ namespace testutil = firebase::firestore::testutil;
 
 - (void)testAppliesServerAckedTransformsToDocuments {
   NSDictionary *docData = @{ @"foo" : @{@"bar" : @"bar-value"}, @"baz" : @"baz-value" };
-  FSTDocument *baseDoc = FSTTestDoc(@"collection/key", 0, docData, NO);
+  FSTDocument *baseDoc = FSTTestDoc("collection/key", 0, docData, NO);
 
   FSTMutation *transform = FSTTestTransformMutation(@"collection/key", @[ @"foo.bar" ]);
 
@@ -144,22 +145,22 @@ namespace testutil = firebase::firestore::testutil;
   NSDictionary *expectedData =
       @{ @"foo" : @{@"bar" : _timestamp.approximateDateValue},
          @"baz" : @"baz-value" };
-  XCTAssertEqualObjects(transformedDoc, FSTTestDoc(@"collection/key", 0, expectedData, NO));
+  XCTAssertEqualObjects(transformedDoc, FSTTestDoc("collection/key", 0, expectedData, NO));
 }
 
 - (void)testDeleteDeletes {
   NSDictionary *docData = @{@"foo" : @"bar"};
-  FSTDocument *baseDoc = FSTTestDoc(@"collection/key", 0, docData, NO);
+  FSTDocument *baseDoc = FSTTestDoc("collection/key", 0, docData, NO);
 
   FSTMutation *mutation = FSTTestDeleteMutation(@"collection/key");
   FSTMaybeDocument *result =
       [mutation applyTo:baseDoc baseDocument:baseDoc localWriteTime:_timestamp];
-  XCTAssertEqualObjects(result, FSTTestDeletedDoc(@"collection/key", 0));
+  XCTAssertEqualObjects(result, FSTTestDeletedDoc("collection/key", 0));
 }
 
 - (void)testSetWithMutationResult {
   NSDictionary *docData = @{@"foo" : @"bar"};
-  FSTDocument *baseDoc = FSTTestDoc(@"collection/key", 0, docData, NO);
+  FSTDocument *baseDoc = FSTTestDoc("collection/key", 0, docData, NO);
 
   FSTMutation *set = FSTTestSetMutation(@"collection/key", @{@"foo" : @"new-bar"});
   FSTMutationResult *mutationResult =
@@ -170,12 +171,12 @@ namespace testutil = firebase::firestore::testutil;
                            mutationResult:mutationResult];
 
   NSDictionary *expectedData = @{@"foo" : @"new-bar"};
-  XCTAssertEqualObjects(setDoc, FSTTestDoc(@"collection/key", 0, expectedData, NO));
+  XCTAssertEqualObjects(setDoc, FSTTestDoc("collection/key", 0, expectedData, NO));
 }
 
 - (void)testPatchWithMutationResult {
   NSDictionary *docData = @{@"foo" : @"bar"};
-  FSTDocument *baseDoc = FSTTestDoc(@"collection/key", 0, docData, NO);
+  FSTDocument *baseDoc = FSTTestDoc("collection/key", 0, docData, NO);
 
   FSTMutation *patch = FSTTestPatchMutation("collection/key", @{@"foo" : @"new-bar"}, {});
   FSTMutationResult *mutationResult =
@@ -186,7 +187,7 @@ namespace testutil = firebase::firestore::testutil;
                                  mutationResult:mutationResult];
 
   NSDictionary *expectedData = @{@"foo" : @"new-bar"};
-  XCTAssertEqualObjects(patchedDoc, FSTTestDoc(@"collection/key", 0, expectedData, NO));
+  XCTAssertEqualObjects(patchedDoc, FSTTestDoc("collection/key", 0, expectedData, NO));
 }
 
 #define ASSERT_VERSION_TRANSITION(mutation, base, expected)                                 \
@@ -204,11 +205,11 @@ namespace testutil = firebase::firestore::testutil;
  * Tests the transition table documented in FSTMutation.h.
  */
 - (void)testTransitions {
-  FSTDocument *docV0 = FSTTestDoc(@"collection/key", 0, @{}, NO);
-  FSTDeletedDocument *deletedV0 = FSTTestDeletedDoc(@"collection/key", 0);
+  FSTDocument *docV0 = FSTTestDoc("collection/key", 0, @{}, NO);
+  FSTDeletedDocument *deletedV0 = FSTTestDeletedDoc("collection/key", 0);
 
-  FSTDocument *docV3 = FSTTestDoc(@"collection/key", 3, @{}, NO);
-  FSTDeletedDocument *deletedV3 = FSTTestDeletedDoc(@"collection/key", 3);
+  FSTDocument *docV3 = FSTTestDoc("collection/key", 3, @{}, NO);
+  FSTDeletedDocument *deletedV3 = FSTTestDeletedDoc("collection/key", 3);
 
   FSTMutation *setMutation = FSTTestSetMutation(@"collection/key", @{});
   FSTMutation *patchMutation = FSTTestPatchMutation("collection/key", {}, {});