Introduce test cases for NextWordPosition()

This patch introduces test cases for |NextWordPosition()| to record current
behavior as a preparation of the patch[1].

[1] http://crrev.com/c/737981 Introduce TextOffsetMapping to simplify
word/paragraph selection

Bug: 778507
Change-Id: Ic98cdea94e5be2f3d13448aa9e087a02b70a0df0
Reviewed-on: https://chromium-review.googlesource.com/895236
Commit-Queue: Yoshifumi Inoue <yosin@chromium.org>
Reviewed-by: Yoichi Osato <yoichio@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533577}

third_party/WebKit/Source/core/editing/VisibleUnits.h

@@ -149,7 +149,7 @@ EndOfWordPosition(const VisiblePositionInFlatTree&,
 CORE_EXPORT VisiblePositionInFlatTree
 EndOfWord(const VisiblePositionInFlatTree&, EWordSide = kNextWordIfOnBoundary);
 VisiblePosition PreviousWordPosition(const VisiblePosition&);
-VisiblePosition NextWordPosition(const VisiblePosition&);
+CORE_EXPORT VisiblePosition NextWordPosition(const VisiblePosition&);
 
 // sentences
 CORE_EXPORT VisiblePosition StartOfSentence(const VisiblePosition&);

third_party/WebKit/Source/core/editing/VisibleUnitsWordTest.cpp

@@ -33,6 +33,15 @@ class VisibleUnitsWordTest : public EditingTestBase {
                           .DeepEquivalent())
             .Build());
   }
+
+  std::string DoNextWord(const std::string& selection_text) {
+    const Position position = SetSelectionTextToBody(selection_text).Base();
+    return GetSelectionTextFromBody(
+        SelectionInDOMTree::Builder()
+            .Collapse(NextWordPosition(CreateVisiblePosition(position))
+                          .DeepEquivalent())
+            .Build());
+  }
 };
 
 TEST_F(VisibleUnitsWordTest, StartOfWordBasic) {
@@ -211,4 +220,54 @@ TEST_F(VisibleUnitsWordTest, EndOfWordTextSecurity) {
   EXPECT_EQ("abc<s>foo bar</s>baz|", DoEndOfWord("abc<s>foo bar</s>b|az"));
 }
 
+TEST_F(VisibleUnitsWordTest, NextWordBasic) {
+  EXPECT_EQ("<p> (1|) abc def</p>", DoNextWord("<p>| (1) abc def</p>"));
+  EXPECT_EQ("<p> (1|) abc def</p>", DoNextWord("<p> |(1) abc def</p>"));
+  EXPECT_EQ("<p> (1|) abc def</p>", DoNextWord("<p> (|1) abc def</p>"));
+  EXPECT_EQ("<p> (1) abc| def</p>", DoNextWord("<p> (1|) abc def</p>"));
+  EXPECT_EQ("<p> (1) abc| def</p>", DoNextWord("<p> (1)| abc def</p>"));
+  EXPECT_EQ("<p> (1) abc| def</p>", DoNextWord("<p> (1) |abc def</p>"));
+  EXPECT_EQ("<p> (1) abc| def</p>", DoNextWord("<p> (1) a|bc def</p>"));
+  EXPECT_EQ("<p> (1) abc| def</p>", DoNextWord("<p> (1) ab|c def</p>"));
+  EXPECT_EQ("<p> (1) abc def|</p>", DoNextWord("<p> (1) abc| def</p>"));
+  EXPECT_EQ("<p> (1) abc def|</p>", DoNextWord("<p> (1) abc |def</p>"));
+  EXPECT_EQ("<p> (1) abc def|</p>", DoNextWord("<p> (1) abc d|ef</p>"));
+  EXPECT_EQ("<p> (1) abc def|</p>", DoNextWord("<p> (1) abc de|f</p>"));
+  EXPECT_EQ("<p> (1) abc def|</p>", DoNextWord("<p> (1) abc def|</p>"));
+  EXPECT_EQ("<p> (1) abc def|</p>", DoNextWord("<p> (1) abc def</p>|"));
+}
+
+TEST_F(VisibleUnitsWordTest, NextWordCrossingBlock) {
+  EXPECT_EQ("<p>abc|</p><p>def</p>", DoNextWord("<p>|abc</p><p>def</p>"));
+  EXPECT_EQ("<p>abc</p><p>def|</p>", DoNextWord("<p>abc|</p><p>def</p>"));
+}
+
+TEST_F(VisibleUnitsWordTest, NextWordMixedEditability) {
+  EXPECT_EQ(
+      "<p contenteditable>"
+      "abc<b contenteditable=\"false\">def ghi</b>|jkl mno</p>",
+      DoNextWord("<p contenteditable>"
+                 "|abc<b contenteditable=false>def ghi</b>jkl mno</p>"));
+  EXPECT_EQ(
+      "<p contenteditable>"
+      "abc<b contenteditable=\"false\">def| ghi</b>jkl mno</p>",
+      DoNextWord("<p contenteditable>"
+                 "abc<b contenteditable=false>|def ghi</b>jkl mno</p>"));
+  EXPECT_EQ(
+      "<p contenteditable>"
+      "abc<b contenteditable=\"false\">def ghi|</b>jkl mno</p>",
+      DoNextWord("<p contenteditable>"
+                 "abc<b contenteditable=false>def |ghi</b>jkl mno</p>"));
+  EXPECT_EQ(
+      "<p contenteditable>"
+      "abc<b contenteditable=\"false\">def ghi|</b>jkl mno</p>",
+      DoNextWord("<p contenteditable>"
+                 "abc<b contenteditable=false>def ghi|</b>jkl mno</p>"));
+}
+
+TEST_F(VisibleUnitsWordTest, NextWordSkipTab) {
+  InsertStyleElement("s { white-space: pre }");
+  EXPECT_EQ("<p><s>\t</s>foo|</p>", DoNextWord("<p><s>\t|</s>foo</p>"));
+}
+
 }  // namespace blink