Switch to `dart format` (#519)

diff --git a/api_benchmark/compile_protos.sh b/api_benchmark/compile_protos.sh
index 4423e5e..03b69d8 100755
--- a/api_benchmark/compile_protos.sh
+++ b/api_benchmark/compile_protos.sh
@@ -2,4 +2,4 @@
 rm -rf lib/generated
 mkdir lib/generated
 protoc --dart_out=lib/generated --plugin=protoc-gen-dart=run_protoc_plugin.sh -Iprotos protos/*.proto
-dartfmt -w lib/generated
+dart format lib/generated
diff --git a/protoc_plugin/Makefile b/protoc_plugin/Makefile
index 53fae39..27406e3 100644
--- a/protoc_plugin/Makefile
+++ b/protoc_plugin/Makefile
@@ -82,7 +82,7 @@
 		-I$(TEST_PROTO_SRC_DIR)\
 		--plugin=protoc-gen-dart=$(realpath $(PLUGIN_PATH))\
 		$(TEST_PROTO_SRCS)
-	dartfmt -w $(TEST_PROTO_DIR)
+	dart format $(TEST_PROTO_DIR)
 
 build-plugin: $(PLUGIN_PATH)
 
@@ -91,7 +91,7 @@
 	rm lib/src/descriptor.pb{json,server}.dart
 	rm lib/src/dart_options.pb{enum,json,server}.dart
 	rm lib/src/plugin.pb{json,server}.dart
-	dartfmt -w lib/src
+	dart format lib/src
 
 protos: $(PLUGIN_PATH) $(TEST_PROTO_LIBS)
 
diff --git a/protoc_plugin/test/generated_message_test.dart b/protoc_plugin/test/generated_message_test.dart
index 1ec3868..29c3f58 100755
--- a/protoc_plugin/test/generated_message_test.dart
+++ b/protoc_plugin/test/generated_message_test.dart
@@ -385,7 +385,7 @@
 
   test('testWriteWholeMessage', () {
     var goldenMessage = const <int>[
-      // no dartfmt
+      // no `dart format`
       0x08, 0x65, 0x10, 0x66, 0x18, 0x67, 0x20, 0x68, 0x28, 0xd2, 0x01, 0x30,
       0xd4, 0x01, 0x3d, 0x6b, 0x00, 0x00, 0x00, 0x41, 0x6c, 0x00, 0x00, 0x00,
       0x00, 0x00, 0x00, 0x00, 0x4d, 0x6d, 0x00, 0x00, 0x00, 0x51, 0x6e, 0x00,
@@ -433,7 +433,7 @@
 
   test('testWriteWholePackedFieldsMessage', () {
     var goldenPackedMessage = const <int>[
-      // no dartfmt
+      // no `dart format`
       0xd2, 0x05, 0x04, 0xd9, 0x04, 0xbd, 0x05, 0xda, 0x05, 0x04, 0xda, 0x04,
       0xbe, 0x05, 0xe2, 0x05, 0x04, 0xdb, 0x04, 0xbf, 0x05, 0xea, 0x05, 0x04,
       0xdc, 0x04, 0xc0, 0x05, 0xf2, 0x05, 0x04, 0xba, 0x09, 0x82, 0x0b, 0xfa,
diff --git a/query_benchmark/compile_protos.sh b/query_benchmark/compile_protos.sh
index 4423e5e..03b69d8 100755
--- a/query_benchmark/compile_protos.sh
+++ b/query_benchmark/compile_protos.sh
@@ -2,4 +2,4 @@
 rm -rf lib/generated
 mkdir lib/generated
 protoc --dart_out=lib/generated --plugin=protoc-gen-dart=run_protoc_plugin.sh -Iprotos protos/*.proto
-dartfmt -w lib/generated
+dart format lib/generated