use FieldPath.fromServerFormat for code simplicity

Author: milaGGL

packages/firestore/test/unit/core/query.test.ts

@@ -50,7 +50,6 @@ import {
   doc,
   expectCorrectComparisons,
   expectEqualitySets,
-  fieldPath,
   filter,
   orderBy,
   orFilter,
@@ -844,12 +843,12 @@ describe('Query', () => {
       query(
         'foo',
         filter('a', '<', 5),
-        filter('a.z', '>', 5),
-        filter(fieldPath('a.a'), '>', 5)
+        filter('a.z', '>', 5), // nested field
+        filter('`a.a`', '>', 5) // field name with dot
       ),
       orderBy('a'),
-      orderBy('a.z'), // nested field
-      orderBy(fieldPath('a.a')), // field name with dot
+      orderBy('a.z'),
+      orderBy('`a.a`'),
       orderBy(DOCUMENT_KEY_NAME)
     );
 

packages/firestore/test/util/helpers.ts

@@ -226,13 +226,10 @@ export function path(path: string, offset?: number): ResourcePath {
   return new ResourcePath(splitPath(path, '/'), offset);
 }
 
-export function field(path: string | FieldPath): FieldPath {
-  return path instanceof FieldPath ? path : new FieldPath(path.split('.'));
+export function field(path: string): FieldPath {
+  return FieldPath.fromServerFormat(path);
 }
 
-export function fieldPath(path: string): FieldPath {
-  return new FieldPath([path]);
-}
 export function fieldIndex(
   collectionGroup: string,
   options: {
@@ -264,11 +261,7 @@ export function blob(...bytes: number[]): Bytes {
   return Bytes.fromUint8Array(new Uint8Array(bytes || []));
 }
 
-export function filter(
-  path: string | FieldPath,
-  op: string,
-  value: unknown
-): FieldFilter {
+export function filter(path: string, op: string, value: unknown): FieldFilter {
   const dataValue = wrap(value);
   const operator = op as Operator;
   return FieldFilter.create(field(path), operator, dataValue);
@@ -743,7 +736,7 @@ export function resumeTokenForSnapshot(
   }
 }
 
-export function orderBy(path: string | FieldPath, op?: string): OrderBy {
+export function orderBy(path: string, op?: string): OrderBy {
   op = op || 'asc';
   debugAssert(op === 'asc' || op === 'desc', 'Unknown direction: ' + op);
   const dir: Direction =