Add simple unit tests (#7543)

* Branch Coverage Tests

FieldChange.java
18% -> 94%
Abbreviation.java
63% -> 88%
SuggestionProviders.java
0% -> 100%

* Boundary Tests

FileHelper.java
-> Boundary testing of an empty file

CitationKeyGenerator.java
-> Boundary testing of testlagepage parser for 0-00 & 1-1

HTMLCharacterChecker.java
-> Null Value Boundary test

* Partition Tests

ParsedEntryLink.java
-> Partition testing of ParsingEntryLink

UpperCaseFormatter.java
-> Partition testing for special characters

CitationStyleCacheTest.java
-> Partition testing of cache storage

* Update SuggestionProvidersTest.java

SPTest typo fix

* CodeStyle Fixes

Checkstyle passed

* Update AbbreviationTest.java

Adjustments for @ellieMayVelasquez feedback
#7543 (review)

* Applying feedback to PR

addressed all comments & suggestions to test files

* checkstyle fix

Author: nasdas-dev

src/test/java/org/jabref/gui/autocompleter/SuggestionProvidersTest.java

@@ -0,0 +1,48 @@
+package org.jabref.gui.autocompleter;
+
+import org.jabref.logic.journals.JournalAbbreviationRepository;
+import org.jabref.model.database.BibDatabase;
+import org.jabref.model.entry.BibEntry;
+import org.jabref.model.entry.field.Field;
+import org.jabref.model.entry.field.FieldFactory;
+import org.jabref.model.entry.field.SpecialField;
+import org.jabref.model.entry.field.StandardField;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.mock;
+
+class SuggestionProvidersTest {
+
+  @Test
+  void getForFieldTest() {
+      BibDatabase database = new BibDatabase();
+      JournalAbbreviationRepository abbreviationRepository = mock(JournalAbbreviationRepository.class);
+      BibEntry entry = new BibEntry();
+      Field personEntryField = StandardField.AUTHOR;
+      Field singleEntryField = StandardField.XREF;
+      Field multipleEntryField = StandardField.XDATA;
+      Field journalEntryField = StandardField.JOURNAL;
+      Field publisherEntryField = StandardField.PUBLISHER;
+      Field specialEntryField = SpecialField.PRINTED;
+      AutoCompletePreferences autoCompletePreferences = new AutoCompletePreferences(true, AutoCompleteFirstNameMode.BOTH, AutoCompletePreferences.NameFormat.BOTH, FieldFactory.parseFieldList(personEntryField.getName() + ";" + singleEntryField.getName() + ";" + multipleEntryField.getName() + ";" + journalEntryField.getName() + ";" + publisherEntryField.getName() + ";" + specialEntryField.getName()), null);
+      SuggestionProviders sp = new SuggestionProviders(database, abbreviationRepository, autoCompletePreferences);
+      SuggestionProviders empty = new SuggestionProviders();
+
+      entry.setField(personEntryField, "Goethe");
+      entry.setField(singleEntryField, "Single");
+      entry.setField(multipleEntryField, "Multiple");
+      entry.setField(journalEntryField, "Journal");
+      entry.setField(publisherEntryField, "Publisher");
+      entry.setField(specialEntryField, "2000");
+
+      assertEquals(org.jabref.gui.autocompleter.EmptySuggestionProvider.class, empty.getForField(personEntryField).getClass());
+      assertEquals(org.jabref.gui.autocompleter.PersonNameSuggestionProvider.class, sp.getForField(personEntryField).getClass());
+      assertEquals(org.jabref.gui.autocompleter.BibEntrySuggestionProvider.class, sp.getForField(singleEntryField).getClass());
+      assertEquals(org.jabref.gui.autocompleter.BibEntrySuggestionProvider.class, sp.getForField(multipleEntryField).getClass());
+      assertEquals(org.jabref.gui.autocompleter.JournalsSuggestionProvider.class, sp.getForField(journalEntryField).getClass());
+      assertEquals(org.jabref.gui.autocompleter.JournalsSuggestionProvider.class, sp.getForField(publisherEntryField).getClass());
+      assertEquals(org.jabref.gui.autocompleter.WordSuggestionProvider.class, sp.getForField(specialEntryField).getClass());
+  }
+}

src/test/java/org/jabref/logic/citationkeypattern/CitationKeyGeneratorTest.java

@@ -739,14 +739,15 @@ void testPagePrefixNull() {
 
     @Test
     void testLastPage() {
-
         assertEquals("27", CitationKeyGenerator.lastPage("7--27"));
         assertEquals("27", CitationKeyGenerator.lastPage("--27"));
         assertEquals("", CitationKeyGenerator.lastPage(""));
         assertEquals("111", CitationKeyGenerator.lastPage("42--111"));
         assertEquals("97", CitationKeyGenerator.lastPage("7,41,73--97"));
         assertEquals("97", CitationKeyGenerator.lastPage("7,41,97--73"));
         assertEquals("43", CitationKeyGenerator.lastPage("43+"));
+        assertEquals("0", CitationKeyGenerator.lastPage("00--0"));
+        assertEquals("1", CitationKeyGenerator.lastPage("1--1"));
     }
 
     @SuppressWarnings("ConstantConditions")

src/test/java/org/jabref/logic/formatter/casechanger/UpperCaseFormatterTest.java

@@ -1,7 +1,10 @@
 package org.jabref.logic.formatter.casechanger;
 
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
+import java.util.stream.Stream;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
@@ -10,24 +13,23 @@
  */
 public class UpperCaseFormatterTest {
 
-    private UpperCaseFormatter formatter;
-
-    @BeforeEach
-    public void setUp() {
-        formatter = new UpperCaseFormatter();
-    }
+    private UpperCaseFormatter formatter = new UpperCaseFormatter();
 
-    @Test
-    public void test() {
-        assertEquals("LOWER", formatter.format("LOWER"));
-        assertEquals("UPPER", formatter.format("upper"));
-        assertEquals("UPPER", formatter.format("UPPER"));
-        assertEquals("UPPER {lower}", formatter.format("upper {lower}"));
-        assertEquals("UPPER {l}OWER", formatter.format("upper {l}ower"));
+    @ParameterizedTest
+    @MethodSource("upperCaseTests")
+    public void upperCasetest(String expectedFormat, String inputFormat) {
+        assertEquals(expectedFormat, formatter.format(inputFormat));
     }
 
-    @Test
-    public void formatExample() {
-        assertEquals("KDE {Amarok}", formatter.format(formatter.getExampleInput()));
+    private static Stream<Arguments> upperCaseTests() {
+        return Stream.of(
+        Arguments.of("LOWER", "LOWER"),
+        Arguments.of("UPPER", "upper"),
+        Arguments.of("UPPER", "UPPER"),
+        Arguments.of("UPPER {lower}", "upper {lower}"),
+        Arguments.of("UPPER {l}OWER", "upper {l}ower"),
+        Arguments.of("1", "1"),
+        Arguments.of("!", "!")
+        );
     }
 }

src/test/java/org/jabref/logic/integrity/HTMLCharacterCheckerTest.java

@@ -9,12 +9,22 @@
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 public class HTMLCharacterCheckerTest {
 
     private final HTMLCharacterChecker checker = new HTMLCharacterChecker();
     private final BibEntry entry = new BibEntry();
 
+    @Test
+    void fieldNullValueCheck() {
+        Exception exception = assertThrows(
+                NullPointerException.class,
+                () -> entry.setField(StandardField.AUTHOR, null),
+                "field value must not be null"
+        );
+    }
+
     @Test
     void titleAcceptsNonHTMLEncodedCharacters() {
         entry.setField(StandardField.TITLE, "Not a single {HTML} character");

src/test/java/org/jabref/model/entry/EntryLinkListTest.java

@@ -10,6 +10,7 @@
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 public class EntryLinkListTest {
@@ -21,6 +22,7 @@ public class EntryLinkListTest {
     private ParsedEntryLink link;
     private BibEntry source;
     private BibEntry target;
+    private BibEntry entry;
 
     @BeforeEach
     public void before() {
@@ -59,6 +61,13 @@ public void givenFieldValueAndDatabaseWhenParsingThenExpectLink() {
         assertEquals(expected, link);
     }
 
+    @Test
+    public void givenBibEntryWhenParsingThenExpectLink() {
+        entry = create("entry");
+        ParsedEntryLink expected = new ParsedEntryLink(entry);
+        assertFalse(expected.getLinkedEntry().isEmpty());
+    }
+
     @Test
     public void givenNullFieldValueAndDatabaseWhenParsingThenExpectLinksIsEmpty() {
         links = EntryLinkList.parse(null, database);

src/test/java/org/jabref/model/util/FileHelperTest.java

@@ -1,5 +1,6 @@
 package org.jabref.model.util;
 
+import java.nio.file.Path;
 import java.util.Optional;
 
 import org.junit.jupiter.api.Test;
@@ -18,4 +19,10 @@ public void fileExtensionFromUrl() {
         final String filePath = "https://link.springer.com/content/pdf/10.1007%2Fs40955-018-0121-9.pdf";
         assertEquals(Optional.of("pdf"), FileHelper.getFileExtension(filePath));
     }
+
+    @Test
+    public void testFileNameEmpty() {
+      Path path = Path.of("/");
+      assertEquals(Optional.of(path), FileHelper.find("", path));
+    }
 }