Accept file URIs as parameters in the RunInView service RPC (flutter/engine#6191)

See https://github.com/flutter/flutter/issues/21348

engine/src/flutter/ci/licenses_golden/licenses_flutter

@@ -481,6 +481,7 @@ LIBRARY: engine
 ORIGIN: ../../../flutter/flutter_kernel_transformers/lib/track_widget_constructor_locations.dart + ../../../LICENSE
 TYPE: LicenseType.bsd
 FILE: ../../../flutter/flutter_kernel_transformers/lib/track_widget_constructor_locations.dart
+FILE: ../../../flutter/fml/paths_unittests.cc
 FILE: ../../../flutter/lib/ui/isolate_name_server.dart
 FILE: ../../../flutter/lib/ui/painting/image_encoding.cc
 FILE: ../../../flutter/lib/ui/painting/image_encoding.h

engine/src/flutter/fml/BUILD.gn

@@ -166,6 +166,7 @@ executable("fml_unittests") {
     "memory/weak_ptr_unittest.cc",
     "message_loop_unittests.cc",
     "message_unittests.cc",
+    "paths_unittests.cc",
     "string_view_unittest.cc",
     "synchronization/thread_annotations_unittest.cc",
     "synchronization/thread_checker_unittest.cc",

engine/src/flutter/fml/paths.cc

@@ -29,5 +29,25 @@ std::string JoinPaths(std::initializer_list<std::string> components) {
   return stream.str();
 }
 
+std::string SanitizeURIEscapedCharacters(const std::string& str) {
+  std::string result;
+  result.reserve(str.size());
+  for (std::string::size_type i = 0; i < str.size(); ++i) {
+    if (str[i] == '%') {
+      if (i > str.size() - 3 || !isxdigit(str[i + 1]) || !isxdigit(str[i + 2]))
+        return "";
+      const std::string hex = str.substr(i + 1, 2);
+      const unsigned char c = strtoul(hex.c_str(), nullptr, 16);
+      if (!c)
+        return "";
+      result += c;
+      i += 2;
+    } else {
+      result += str[i];
+    }
+  }
+  return result;
+}
+
 }  // namespace paths
 }  // namespace fml

engine/src/flutter/fml/paths.h

@@ -22,6 +22,12 @@ std::string AbsolutePath(const std::string& path);
 // Returns the directory name component of the given path.
 std::string GetDirectoryName(const std::string& path);
 
+// Decodes a URI encoded string.
+std::string SanitizeURIEscapedCharacters(const std::string& str);
+
+// Converts a file URI to a path.
+std::string FromURI(const std::string& uri);
+
 }  // namespace paths
 }  // namespace fml
 

engine/src/flutter/fml/paths_unittests.cc

@@ -0,0 +1,17 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "gtest/gtest.h"
+
+#include "flutter/fml/paths.h"
+
+TEST(Paths, SanitizeURI) {
+  ASSERT_EQ(fml::paths::SanitizeURIEscapedCharacters("hello"), "hello");
+  ASSERT_EQ(fml::paths::SanitizeURIEscapedCharacters(""), "");
+  ASSERT_EQ(fml::paths::SanitizeURIEscapedCharacters("hello%20world"),
+            "hello world");
+  ASSERT_EQ(fml::paths::SanitizeURIEscapedCharacters(
+                "%5Chello%5cworld%20foo%20bar%21"),
+            "\\hello\\world foo bar!");
+}

engine/src/flutter/fml/platform/posix/paths_posix.cc

@@ -14,6 +14,9 @@ namespace paths {
 
 namespace {
 
+constexpr char kFileURLPrefix[] = "file://";
+constexpr size_t kFileURLPrefixLength = sizeof(kFileURLPrefix) - 1;
+
 std::string GetCurrentDirectory() {
   char buffer[PATH_MAX];
   FML_CHECK(getcwd(buffer, sizeof(buffer)));
@@ -44,5 +47,13 @@ std::string GetDirectoryName(const std::string& path) {
   return path.substr(0, separator);
 }
 
+std::string FromURI(const std::string& uri) {
+  if (uri.substr(0, kFileURLPrefixLength) != kFileURLPrefix)
+    return uri;
+
+  std::string file_path = uri.substr(kFileURLPrefixLength);
+  return SanitizeURIEscapedCharacters(file_path);
+}
+
 }  // namespace paths
-}  // namespace fml
+}  // namespace fml

engine/src/flutter/fml/platform/win/paths_win.cc

@@ -5,6 +5,7 @@
 #include "flutter/fml/paths.h"
 
 #include <windows.h>
+#include <algorithm>
 
 #include "flutter/fml/paths.h"
 
@@ -13,6 +14,9 @@ namespace paths {
 
 namespace {
 
+constexpr char kFileURLPrefix[] = "file:///";
+constexpr size_t kFileURLPrefixLength = sizeof(kFileURLPrefix) - 1;
+
 size_t RootLength(const std::string& path) {
   if (path.size() == 0)
     return 0;
@@ -77,5 +81,14 @@ std::string GetDirectoryName(const std::string& path) {
   return path.substr(0, separator);
 }
 
+std::string FromURI(const std::string& uri) {
+  if (uri.substr(0, kFileURLPrefixLength) != kFileURLPrefix)
+    return uri;
+
+  std::string file_path = uri.substr(kFileURLPrefixLength);
+  std::replace(file_path.begin(), file_path.end(), '/', '\\');
+  return SanitizeURIEscapedCharacters(file_path);
+}
+
 }  // namespace paths
 }  // namespace fml

engine/src/flutter/shell/common/shell.cc

@@ -865,24 +865,28 @@ bool Shell::OnServiceProtocolRunInView(
     return false;
   }
 
-  auto main_script_file =
-      fml::paths::AbsolutePath(params.at("mainScript").ToString());
+  std::string main_script_path =
+      fml::paths::FromURI(params.at("mainScript").ToString());
+  std::string packages_path =
+      fml::paths::FromURI(params.at("packagesFile").ToString());
+  std::string asset_directory_path =
+      fml::paths::FromURI(params.at("assetDirectory").ToString());
 
   auto main_script_file_mapping =
-      std::make_unique<fml::FileMapping>(main_script_file, false);
+      std::make_unique<fml::FileMapping>(main_script_path, false);
 
   auto isolate_configuration =
       blink::DartVM::IsKernelMapping(main_script_file_mapping.get())
           ? IsolateConfiguration::CreateForSnapshot(
                 std::move(main_script_file_mapping))
-          : IsolateConfiguration::CreateForSource(
-                main_script_file, params.at("packagesFile").ToString());
+          : IsolateConfiguration::CreateForSource(main_script_path,
+                                                  packages_path);
 
   RunConfiguration configuration(std::move(isolate_configuration));
 
-  configuration.AddAssetResolver(std::make_unique<blink::DirectoryAssetBundle>(
-      fml::OpenFile(params.at("assetDirectory").ToString().c_str(),
-                    fml::OpenPermission::kRead, true)));
+  configuration.AddAssetResolver(
+      std::make_unique<blink::DirectoryAssetBundle>(fml::OpenFile(
+          asset_directory_path.c_str(), fml::OpenPermission::kRead, true)));
 
   auto& allocator = response.GetAllocator();
   response.SetObject();