Fix word count issue for Chinese and Japanese

javatests/org/chromium/distiller/StringUtilTest.java

Index: javatests/org/chromium/distiller/StringUtilTest.java
diff --git a/javatests/org/chromium/distiller/StringUtilTest.java b/javatests/org/chromium/distiller/StringUtilTest.java
index 620fbbcc61e8d4c379aa17c7a1c95c819e6e4dff..4867946f7cf2efb0169957c1fdf9c4ae1cccaec7 100644
--- a/javatests/org/chromium/distiller/StringUtilTest.java
+++ b/javatests/org/chromium/distiller/StringUtilTest.java
@@ -5,18 +5,107 @@
 package org.chromium.distiller;
 
 import com.google.gwt.regexp.shared.RegExp;
+import java.util.ArrayList;
+import java.util.List;
 
 public class StringUtilTest extends JsTestCase {
+    public void testFastWordCounter() {
+        List<StringUtil.WordCounter> counters = new ArrayList();
+        counters.add(new StringUtil.FastWordCounter());
+        counters.add(new StringUtil.LetterWordCounter());
+        counters.add(new StringUtil.FullWordCounter());
+
+        for(StringUtil.WordCounter counter: counters) {
+            assertEquals(0, counter.count(""));
+            assertEquals(0, counter.count("  -@# ';]"));
+            assertEquals(1, counter.count("word"));
+            assertEquals(1, counter.count("b'fore"));
+            assertEquals(1, counter.count(" _word.under_score_ "));
+            assertEquals(2, counter.count(" \ttwo\nwords"));
+            assertEquals(2, counter.count(" \ttwo @^@^&(@#$([][;;\nwords"));
+            // Norwegian
+            assertEquals(5, counter.count("dør når på svært dårlig"));
+            assertEquals(5, counter.count("svært få dør av blåbærsyltetøy"));
+            // Greek
+            assertEquals(11, counter.count(
+                    "Παρέμβαση των ΗΠΑ για τα τεχνητά νησιά που κατασκευάζει η Κίνα"));
+            // Arabic
+            assertEquals(6, counter.count("زلزال بقوة 8.5 درجات يضرب اليابان"));
+            // Tibetan
+            assertEquals(1, counter.count("༧གོང་ས་མཆོག་གི་ནང་གི་ངོ་སྤྲོད་ཀྱི་གསུང་ཆོས་ལེགས་གྲུབ།"));
+            // Thai
+            assertEquals(3, counter.count("โซลาร์ อิมพัลส์ทู เหินฟ้าข้ามมหาสมุทร"));
+        }
+    }
+
+    public void testLetterWordCounter() {
+        List<StringUtil.WordCounter> counters = new ArrayList();
+        counters.add(new StringUtil.LetterWordCounter());
+        counters.add(new StringUtil.FullWordCounter());
+
+        for(StringUtil.WordCounter counter: counters) {
+            // Hangul uses space as word delimiter like English.
+            assertEquals(1, counter.count("어"));
+            assertEquals(2, counter.count("한국어 단어"));
+            assertEquals(5, counter.count("한 국 어 단 어"));
+            assertEquals(8, counter.count(
+                    "예비군 훈련장 총기 난사범 최모씨의 군복에서 발견된 유서."));
+        }
+    }
+
+    public void testFullWordCounter() {
+        StringUtil.WordCounter counter = new StringUtil.FullWordCounter();
+        // One Chinese sentence, or a series of Japanese glyphs should not be treated
+        // as a single word.
+        assertTrue(counter.count("一個中文句子不應該當成一個字") > 1); // zh-Hant
+        assertTrue(counter.count("中国和马来西亚使用简体字") > 1); // zh-Hans
+        assertTrue(counter.count("ファイナルファンタジー") > 1); // Katakana
+        assertTrue(counter.count("いってらっしゃい") > 1); // Hiragana
+        assertTrue(counter.count("仏仮駅辺") > 1); // Kanji
+        // However, treating each Chinese/Japanese glyph as a word is also wrong.
+        assertTrue(counter.count("一個中文句子不應該當成一個字") < 14);
+        assertTrue(counter.count("中国和马来西亚使用简体字") < 12);
+        assertTrue(counter.count("ファイナルファンタジー") < 11);
+        assertTrue(counter.count("いってらっしゃい") < 8);
+        assertTrue(counter.count("仏仮駅辺") < 4);
+        // Even if they are separated by spaces.
+        assertTrue(counter.count("一 個 中 文 句 子 不 應 該 當 成 一 個 字") < 14);
+        assertTrue(counter.count("中 国 和 马 来 西 亚 使 用 简 体 字") < 12);
+        assertTrue(counter.count("フ ァ イ ナ ル フ ァ ン タ ジ ー") < 11);
+        assertTrue(counter.count("い っ て ら っ し ゃ い") < 8);
+        assertTrue(counter.count("仏 仮 駅 辺") < 4);
+
+        assertEquals(1, counter.count("字"));
+        assertEquals(1, counter.count("が"));
+
+        // Mixing ASCII words and Chinese/Japanese glyphs
+        assertEquals(2, counter.count("word字"));
+        assertEquals(2, counter.count("word 字"));
+    }
+
+    public void testSelectWordCounter() {
+        StringUtil.WordCounter counter;
+
+        counter = StringUtil.selectWordCounter("abc");
+        assertTrue(counter instanceof StringUtil.FastWordCounter);
+
+        counter = StringUtil.selectWordCounter("어");
+        assertTrue(counter instanceof StringUtil.LetterWordCounter);
+
+        counter = StringUtil.selectWordCounter("字");
+        assertTrue(counter instanceof StringUtil.FullWordCounter);
+    }
+
     public void testCountWords() {
-        assertEquals(0, StringUtil.countWords(""));
-        assertEquals(0, StringUtil.countWords("  -@# ';]"));
-        assertEquals(1, StringUtil.countWords("word"));
-        assertEquals(1, StringUtil.countWords("b'fore"));
-        assertEquals(1, StringUtil.countWords(" _word.under_score_ "));
-        assertEquals(2, StringUtil.countWords(" \ttwo\nwords"));
-        assertEquals(2, StringUtil.countWords(" \ttwo @^@^&(@#$([][;;\nwords"));
-        assertEquals(5, StringUtil.countWords("dør når på svært dårlig"));
-        assertEquals(5, StringUtil.countWords("svært få dør av blåbærsyltetøy"));
+        StringUtil.setWordCounter("");
+        assertEquals(2, StringUtil.countWords("two words"));
+        assertEquals(0, StringUtil.countWords("어"));
+        StringUtil.setWordCounter("어");
+        assertEquals(1, StringUtil.countWords("어"));
+        assertEquals(0, StringUtil.countWords("字"));
+        StringUtil.setWordCounter("字");
+        assertEquals(1, StringUtil.countWords("字"));
+        // Make sure the internal WordCounter is restored to FullWordCounter in the end.
     }
 
     public void testIsWhitespace() {