arc: Move GetFileNameForDocument to public utilities.

This function will be used in Recent. As a bonus, unit tests are added.

Bug: 742722
Test: unit_tests
Change-Id: I0c5d6271e7845fb0d7f86047414f652e049348f3
Reviewed-on: https://chromium-review.googlesource.com/588811
Commit-Queue: Shuhei Takahashi <nya@chromium.org>
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491972}

chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.cc

@@ -4,6 +4,7 @@
 
 #include "chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.h"
 
+#include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
@@ -11,8 +12,6 @@
 #include "base/files/file.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
-#include "base/stl_util.h"
-#include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/time/time.h"
 #include "chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util.h"
@@ -24,46 +23,6 @@ using EntryList = storage::AsyncFileUtil::EntryList;
 
 namespace arc {
 
-namespace {
-
-// Computes a file name for a document.
-// TODO(crbug.com/675868): Consolidate with the similar logic for Drive.
-base::FilePath::StringType GetFileNameForDocument(
-    const mojom::DocumentPtr& document) {
-  base::FilePath::StringType filename = document->display_name;
-
-  // Replace path separators appearing in the file name.
-  // Chrome OS is POSIX and kSeparators is "/".
-  base::ReplaceChars(filename, base::FilePath::kSeparators, "_", &filename);
-
-  // Do not allow an empty file name and all-dots file names.
-  if (filename.empty() ||
-      filename.find_first_not_of('.', 0) == std::string::npos) {
-    filename = "_";
-  }
-
-  // Since Chrome detects MIME type from file name extensions, we need to change
-  // the file name extension of the document if it does not match with its MIME
-  // type.
-  // For example, Audio Media Provider presents a music file with its title as
-  // the file name.
-  base::FilePath::StringType extension =
-      base::ToLowerASCII(base::FilePath(filename).Extension());
-  if (!extension.empty())
-    extension = extension.substr(1);  // Strip the leading dot.
-  std::vector<base::FilePath::StringType> possible_extensions =
-      GetExtensionsForArcMimeType(document->mime_type);
-  if (!possible_extensions.empty() &&
-      !base::ContainsValue(possible_extensions, extension)) {
-    filename =
-        base::FilePath(filename).AddExtension(possible_extensions[0]).value();
-  }
-
-  return filename;
-}
-
-}  // namespace
-
 // static
 const int64_t ArcDocumentsProviderRoot::kInvalidWatcherId = -1;
 // static

chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util.cc

@@ -7,6 +7,7 @@
 #include <algorithm>
 #include <utility>
 
+#include "base/stl_util.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
@@ -216,4 +217,39 @@ std::vector<base::FilePath::StringType> GetExtensionsForArcMimeType(
   return std::vector<base::FilePath::StringType>();
 }
 
+// TODO(crbug.com/675868): Consolidate with the similar logic for Drive.
+base::FilePath::StringType GetFileNameForDocument(
+    const mojom::DocumentPtr& document) {
+  base::FilePath::StringType filename = document->display_name;
+
+  // Replace path separators appearing in the file name.
+  // Chrome OS is POSIX and kSeparators is "/".
+  base::ReplaceChars(filename, base::FilePath::kSeparators, "_", &filename);
+
+  // Do not allow an empty file name and all-dots file names.
+  if (filename.empty() ||
+      filename.find_first_not_of('.', 0) == std::string::npos) {
+    filename = "_";
+  }
+
+  // Since Chrome detects MIME type from file name extensions, we need to change
+  // the file name extension of the document if it does not match with its MIME
+  // type.
+  // For example, Audio Media Provider presents a music file with its title as
+  // the file name.
+  base::FilePath::StringType extension =
+      base::ToLowerASCII(base::FilePath(filename).Extension());
+  if (!extension.empty())
+    extension = extension.substr(1);  // Strip the leading dot.
+  std::vector<base::FilePath::StringType> possible_extensions =
+      GetExtensionsForArcMimeType(document->mime_type);
+  if (!possible_extensions.empty() &&
+      !base::ContainsValue(possible_extensions, extension)) {
+    filename =
+        base::FilePath(filename).AddExtension(possible_extensions[0]).value();
+  }
+
+  return filename;
+}
+
 }  // namespace arc

chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util.h

@@ -11,6 +11,7 @@
 #include <vector>
 
 #include "base/files/file_path.h"
+#include "components/arc/common/file_system.mojom.h"
 
 class GURL;
 
@@ -70,6 +71,10 @@ GURL BuildDocumentUrl(const std::string& authority,
 std::vector<base::FilePath::StringType> GetExtensionsForArcMimeType(
     const std::string& mime_type);
 
+// Computes a file name for a document.
+base::FilePath::StringType GetFileNameForDocument(
+    const mojom::DocumentPtr& document);
+
 }  // namespace arc
 
 #endif  // CHROME_BROWSER_CHROMEOS_ARC_FILEAPI_ARC_DOCUMENTS_PROVIDER_UTIL_H_

chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util_unittest.cc

@@ -12,6 +12,14 @@ namespace arc {
 
 namespace {
 
+mojom::DocumentPtr MakeDocument(const std::string& display_name,
+                                const std::string& mime_type) {
+  mojom::DocumentPtr document = mojom::Document::New();
+  document->display_name = display_name;
+  document->mime_type = mime_type;
+  return document;
+}
+
 TEST(ArcDocumentsProviderUtilTest, EscapePathComponent) {
   EXPECT_EQ("", EscapePathComponent(""));
   EXPECT_EQ("%2E", EscapePathComponent("."));
@@ -221,6 +229,22 @@ TEST(ArcDocumentsProviderUtilTest, GetExtensionsForArcMimeType) {
   EXPECT_EQ(0u, GetExtensionsForArcMimeType("application/octet-stream").size());
 }
 
+TEST(ArcDocumentsProviderUtilTest, GetFileNameForDocument) {
+  EXPECT_EQ("kitten.png",
+            GetFileNameForDocument(MakeDocument("kitten.png", "image/png")));
+  EXPECT_EQ("a__b.png",
+            GetFileNameForDocument(MakeDocument("a//b.png", "image/png")));
+  EXPECT_EQ("_.png", GetFileNameForDocument(MakeDocument("", "image/png")));
+  EXPECT_EQ("_.png", GetFileNameForDocument(MakeDocument(".", "image/png")));
+  EXPECT_EQ("_.png", GetFileNameForDocument(MakeDocument("..", "image/png")));
+  EXPECT_EQ("_.png",
+            GetFileNameForDocument(MakeDocument("......", "image/png")));
+  EXPECT_EQ("kitten.png",
+            GetFileNameForDocument(MakeDocument("kitten", "image/png")));
+  EXPECT_EQ("kitten",
+            GetFileNameForDocument(MakeDocument("kitten", "abc/xyz")));
+}
+
 }  // namespace
 
 }  // namespace arc