[opennlp] branch main updated: OPENNLP-1229 PorterStemmer stem function giving wrong output

[rzo1]

This is an automated email from the ASF dual-hosted git repository.

rzo1 pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/opennlp.git


The following commit(s) were added to refs/heads/main by this push:
     new 3c6670b9 OPENNLP-1229 PorterStemmer stem function giving wrong output
3c6670b9 is described below

commit 3c6670b948be1b7c44a2909a14790e0522e4c545
Author: Martin Wiesner <martin.wies...@hs-heilbronn.de>
AuthorDate: Sun Feb 26 16:34:01 2023 +0100

    OPENNLP-1229 PorterStemmer stem function giving wrong output
    
    - adds unit test to verify "this" is stemmed to "thi", as expected for 
`PorterStemmer`
    - adds unit test to verify "this" is stemmed to "this" for `SnowballStemmer`
    - adds additional ParameterizedTest in PorterStemmerTest
    - improves JavaDoc along the path
---
 .../java/opennlp/tools/stemmer/PorterStemmer.java  | 12 ++++----
 .../opennlp/tools/stemmer/PorterStemmerTest.java   | 35 +++++++++++++++-------
 .../opennlp/tools/stemmer/SnowballStemmerTest.java |  6 ++++
 3 files changed, 37 insertions(+), 16 deletions(-)

diff --git 
a/opennlp-tools/src/main/java/opennlp/tools/stemmer/PorterStemmer.java 
b/opennlp-tools/src/main/java/opennlp/tools/stemmer/PorterStemmer.java
index a9e6f18b..65cdbdb5 100644
--- a/opennlp-tools/src/main/java/opennlp/tools/stemmer/PorterStemmer.java
+++ b/opennlp-tools/src/main/java/opennlp/tools/stemmer/PorterStemmer.java
@@ -44,12 +44,12 @@
 package opennlp.tools.stemmer;
 
 /**
- *
- * Stemmer, implementing the Porter Stemming Algorithm
- *
- * The Stemmer class transforms a word into its root form.  The input
- * word can be provided a character at time (by calling add()), or at once
- * by calling one of the various stem(something) methods.
+ * A {@link Stemmer}, implementing the <a 
href="https://tartarus.org/martin/PorterStemmer/";>
+ * Porter Stemming Algorithm</a>
+ * <p>
+ * The Stemmer implementation transforms a word into its root form. The input
+ * word can be provided a character at time (by calling {@link #add(char)}),
+ * or at once by calling one of the various {@code stem(..)} methods.
  */
 // CHECKSTYLE:OFF
 public class PorterStemmer implements Stemmer {
diff --git 
a/opennlp-tools/src/test/java/opennlp/tools/stemmer/PorterStemmerTest.java 
b/opennlp-tools/src/test/java/opennlp/tools/stemmer/PorterStemmerTest.java
index f43c66b6..aab212f4 100644
--- a/opennlp-tools/src/test/java/opennlp/tools/stemmer/PorterStemmerTest.java
+++ b/opennlp-tools/src/test/java/opennlp/tools/stemmer/PorterStemmerTest.java
@@ -18,23 +18,38 @@
 package opennlp.tools.stemmer;
 
 import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 
 public class PorterStemmerTest {
 
-  private PorterStemmer stemmer = new PorterStemmer();
+  private PorterStemmer stemmer;
 
-  @Test
-  void testNotNull() {
-    Assertions.assertNotNull(stemmer);
+  @BeforeEach
+  public void setup() {
+    stemmer = new PorterStemmer();
   }
 
   @Test
-  void testStemming() {
-    Assertions.assertEquals(stemmer.stem("deny"), "deni");
-    Assertions.assertEquals(stemmer.stem("declining"), "declin");
-    Assertions.assertEquals(stemmer.stem("diversity"), "divers");
-    Assertions.assertEquals(stemmer.stem("divers"), "diver");
-    Assertions.assertEquals(stemmer.stem("dental"), "dental");
+  void testStem() {
+    Assertions.assertEquals("deni", stemmer.stem("deny"));
+    Assertions.assertEquals("declin", stemmer.stem("declining"));
+    Assertions.assertEquals("divers", stemmer.stem("diversity"));
+    Assertions.assertEquals("diver", stemmer.stem("divers"));
+    Assertions.assertEquals("dental", stemmer.stem("dental"));
+  }
+
+  @ParameterizedTest
+  @ValueSource(strings = {"likes", "liked", "likely", "liking"})
+  void testStemLike(String input) {
+    Assertions.assertEquals("like", stemmer.stem(input));
+  }
+
+
+  @Test // Context: OpenNLP-1229 - This is here to demonstrate & verify.
+  void testStemThis() {
+    Assertions.assertEquals("thi", stemmer.stem("this"));
   }
 }
diff --git 
a/opennlp-tools/src/test/java/opennlp/tools/stemmer/SnowballStemmerTest.java 
b/opennlp-tools/src/test/java/opennlp/tools/stemmer/SnowballStemmerTest.java
index 54335417..3c33fde3 100644
--- a/opennlp-tools/src/test/java/opennlp/tools/stemmer/SnowballStemmerTest.java
+++ b/opennlp-tools/src/test/java/opennlp/tools/stemmer/SnowballStemmerTest.java
@@ -69,6 +69,12 @@ public class SnowballStemmerTest {
 
   }
 
+  @Test // Context: OpenNLP-1229 - This is here to demonstrate & verify.
+  void testStemThis() {
+    SnowballStemmer stemmer = new SnowballStemmer(ALGORITHM.ENGLISH);
+    Assertions.assertEquals("this", stemmer.stem("this"));
+  }
+
   @Test
   void testFinnish() {
     SnowballStemmer stemmer = new SnowballStemmer(ALGORITHM.FINNISH);