[#366] Fix NullPointerException when accessing unfilled displayName i…

…n StandaloneConfig (#368)

In our user guide, we allow most of the fields under the authors'
configuration to be optional other than the GitHub Id. Particularly
`Display Name`, which is suppose to use GitHub Id value when it is not
provided. However, when the display name is not filled in the
standalone config, the program crashes due to a NullPointerException.

This is because standalone config adopts the json format. When a field
is not filled in, in the json file, it will be initialized as null when
deserialized into a java object. This was unforeseen and was left
unchecked when accessing the variable.

Let's fix this by returning an empty string as the default value of
display name in the event of a null case, and also include unit tests
for StandaloneConfig parser.

src/main/java/reposense/model/Author.java

@@ -46,6 +46,14 @@ public Author(StandaloneAuthor sa) {
         updateIgnoreGlobMatcher();
     }
 
+    public Author(Author another) {
+        this.gitId = another.gitId;
+        this.displayName = another.gitId;
+        this.authorAliases = another.authorAliases;
+        this.ignoreGlobList = another.authorAliases;
+        this.ignoreGlobMatcher = another.ignoreGlobMatcher;
+    }
+
     /**
      * Checks that all the strings in the {@code ignoreGlobList} only contains commonly used glob patterns.
      * @throws IllegalArgumentException if any of the values do not meet the criteria.

src/main/java/reposense/model/StandaloneAuthor.java

@@ -17,6 +17,10 @@ public String getGithubId() {
     }
 
     public String getDisplayName() {
+        if (displayName == null) {
+            return "";
+        }
+
         return displayName;
     }
 

src/test/java/reposense/parser/RepoConfigurationTest.java

@@ -49,8 +49,9 @@ public class RepoConfigurationTest {
 
     private static final List<String> REPO_LEVEL_GLOB_LIST = Arrays.asList("collated**");
     private static final List<String> FIRST_AUTHOR_GLOB_LIST =
-            Arrays.asList("collated**", "*.aa1", "**.aa2", "**.java");
-    private static final List<String> SECOND_AUTHOR_GLOB_LIST = Arrays.asList("collated**", "**[!(.md)]");
+            Arrays.asList("*.aa1", "**.aa2", "**.java", "collated**");
+    private static final List<String> SECOND_AUTHOR_GLOB_LIST = Arrays.asList("**[!(.md)]", "collated**");
+    private static final List<String> THIRD_AUTHOR_GLOB_LIST = Arrays.asList("", "collated**");
 
     private static final List<String> CONFIG_FORMATS = Arrays.asList("java", "adoc", "md");
     private static final List<String> CLI_FORMATS = Arrays.asList("css", "html");
@@ -59,9 +60,14 @@ public class RepoConfigurationTest {
 
     @BeforeClass
     public static void setUp() throws InvalidLocationException {
+        FIRST_AUTHOR.setAuthorAliases(FIRST_AUTHOR_ALIASES);
+        SECOND_AUTHOR.setAuthorAliases(SECOND_AUTHOR_ALIASES);
+        THIRD_AUTHOR.setAuthorAliases(THIRD_AUTHOR_ALIASES);
+        FOURTH_AUTHOR.setAuthorAliases(FOURTH_AUTHOR_ALIASES);
+
         FIRST_AUTHOR.setIgnoreGlobList(FIRST_AUTHOR_GLOB_LIST);
         SECOND_AUTHOR.setIgnoreGlobList(SECOND_AUTHOR_GLOB_LIST);
-        THIRD_AUTHOR.setIgnoreGlobList(REPO_LEVEL_GLOB_LIST);
+        THIRD_AUTHOR.setIgnoreGlobList(THIRD_AUTHOR_GLOB_LIST);
         FOURTH_AUTHOR.setIgnoreGlobList(REPO_LEVEL_GLOB_LIST);
 
         List<Author> expectedAuthors = new ArrayList<>();
@@ -115,12 +121,14 @@ public void repoConfig_usesStandaloneConfig_success() throws InvalidLocationExce
     public void repoConfig_ignoresStandaloneConfig_success()
             throws ParseException, GitDownloaderException, IOException {
         List<Author> expectedAuthors = new ArrayList<>();
-        expectedAuthors.add(FIRST_AUTHOR);
+        Author author = new Author(FIRST_AUTHOR);
+        author.setIgnoreGlobList(REPO_LEVEL_GLOB_LIST);
+        expectedAuthors.add(author);
 
         RepoConfiguration expectedConfig = new RepoConfiguration(TEST_REPO_DELTA, "master");
         expectedConfig.setAuthorList(expectedAuthors);
-        expectedConfig.addAuthorAliases(FIRST_AUTHOR, FIRST_AUTHOR_ALIASES);
-        expectedConfig.setAuthorDisplayName(FIRST_AUTHOR, "Ahm");
+        expectedConfig.addAuthorAliases(author, FIRST_AUTHOR_ALIASES);
+        expectedConfig.setAuthorDisplayName(author, "Ahm");
 
         expectedConfig.setIgnoreGlobList(REPO_LEVEL_GLOB_LIST);
         expectedConfig.setFormats(CONFIG_FORMATS);

src/test/java/reposense/parser/StandaloneConfigJsonParserTest.java

@@ -0,0 +1,107 @@
+package reposense.parser;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.Arrays;
+
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import com.google.gson.JsonSyntaxException;
+
+import reposense.model.Author;
+import reposense.model.RepoConfiguration;
+import reposense.model.StandaloneConfig;
+import reposense.util.TestUtil;
+
+public class StandaloneConfigJsonParserTest {
+
+    private static final Path STANDALONE_MALFORMED_CONFIG = new File(
+            StandaloneConfigJsonParserTest.class.getClassLoader()
+            .getResource("StandaloneConfigJsonParserTest/standaloneConfig_malformedJson.json").getFile()).toPath();
+
+    private static final Path STANDALONE_UNKNOWN_PROPERTY_CONFIG = new File(
+            StandaloneConfigJsonParserTest.class.getClassLoader().getResource(
+                    "StandaloneConfigJsonParserTest/standaloneConfig_unknownPropertyInJson.json").getFile()).toPath();
+
+    private static final Path STANDALONE_CONFIG_FULL = new File(
+            StandaloneConfigJsonParserTest.class.getClassLoader().getResource(
+                    "StandaloneConfigJsonParserTest/standaloneConfig_full.json").getFile()).toPath();
+
+    private static final Path STANDALONE_CONFIG_EMPTY_TEXT_FILE = new File(
+            StandaloneConfigJsonParserTest.class.getClassLoader().getResource(
+                    "StandaloneConfigJsonParserTest/standaloneConfig_emptyText.json").getFile()).toPath();
+
+    private static final Path STANDALONE_CONFIG_EMPTY_JSON_FILE = new File(
+            StandaloneConfigJsonParserTest.class.getClassLoader().getResource(
+                    "StandaloneConfigJsonParserTest/standaloneConfig_emptyJson.json").getFile()).toPath();
+
+    private static final Path STANDALONE_CONFIG_GITHUBID_ONLY = new File(
+            StandaloneConfigJsonParserTest.class.getClassLoader().getResource(
+                    "StandaloneConfigJsonParserTest/standaloneConfig_githubId_only.json").getFile()).toPath();
+
+    private static final String TEST_DUMMY_LOCATION = "https://github.com/reposense/RepoSense.git";
+
+    private static RepoConfiguration EXPECTED_GITHUBID_ONLY_REPOCONFIG;
+    private static RepoConfiguration EXPECTED_FULL_REPOCONFIG;
+
+    @BeforeClass
+    public static void setUp() throws InvalidLocationException {
+        Author author = new Author("yong24s");
+        author.setAuthorAliases(Arrays.asList("Yong Hao TENG"));
+        author.setIgnoreGlobList(Arrays.asList("**.css", "**.html", "**.jade", "**.js"));
+
+        EXPECTED_GITHUBID_ONLY_REPOCONFIG = new RepoConfiguration(TEST_DUMMY_LOCATION);
+        EXPECTED_GITHUBID_ONLY_REPOCONFIG.setFormats(ArgsParser.DEFAULT_FORMATS);
+        EXPECTED_GITHUBID_ONLY_REPOCONFIG.setAuthorList(Arrays.asList(new Author("yong24s")));
+
+        EXPECTED_FULL_REPOCONFIG = new RepoConfiguration(TEST_DUMMY_LOCATION);
+        EXPECTED_FULL_REPOCONFIG.setFormats(Arrays.asList("gradle", "jade", "java", "js", "md", "scss", "yml"));
+        EXPECTED_FULL_REPOCONFIG.setIgnoreCommitList(Arrays.asList("7b96c563eb2d3612aa5275364333664a18f01491"));
+        EXPECTED_FULL_REPOCONFIG.setIgnoreGlobList(Arrays.asList("**.adoc", "collate**"));
+        EXPECTED_FULL_REPOCONFIG.setAuthorList(Arrays.asList(author));
+        EXPECTED_FULL_REPOCONFIG.setAuthorDisplayName(author, "Yong Hao");
+        EXPECTED_FULL_REPOCONFIG.addAuthorAliases(author, Arrays.asList(author.getGitId()));
+        EXPECTED_FULL_REPOCONFIG.addAuthorAliases(author, author.getAuthorAliases());
+    }
+
+    @Test
+    public void standaloneConfig_parseEmptyTextFile_success() throws IOException {
+        new StandaloneConfigJsonParser().parse(STANDALONE_CONFIG_EMPTY_TEXT_FILE);
+    }
+
+    @Test
+    public void standaloneConfig_parseEmptyJsonFile_success() throws IOException {
+        new StandaloneConfigJsonParser().parse(STANDALONE_CONFIG_EMPTY_JSON_FILE);
+    }
+
+    @Test
+    public void standaloneConfig_ignoresUnknownProperty_success() throws IOException {
+        new StandaloneConfigJsonParser().parse(STANDALONE_UNKNOWN_PROPERTY_CONFIG);
+    }
+
+    @Test
+    public void standaloneConfig_correctConfig_success() throws IOException, InvalidLocationException {
+        StandaloneConfig config = new StandaloneConfigJsonParser().parse(STANDALONE_CONFIG_FULL);
+        assertSameConfig(EXPECTED_FULL_REPOCONFIG, config);
+    }
+
+    @Test
+    public void standaloneConfig_githubIdOnlyConfig_success() throws IOException, InvalidLocationException {
+        StandaloneConfig config = new StandaloneConfigJsonParser().parse(STANDALONE_CONFIG_GITHUBID_ONLY);
+        assertSameConfig(EXPECTED_GITHUBID_ONLY_REPOCONFIG, config);
+    }
+
+    @Test(expected = JsonSyntaxException.class)
+    public void standaloneConfig_malformedJsonFile_throwsJsonSyntaxException() throws IOException {
+        new StandaloneConfigJsonParser().parse(STANDALONE_MALFORMED_CONFIG);
+    }
+
+    private void assertSameConfig(RepoConfiguration expectedRepoConfig, StandaloneConfig actualStandaloneConfig)
+            throws InvalidLocationException {
+        RepoConfiguration actualRepoConfig = new RepoConfiguration(TEST_DUMMY_LOCATION);
+        actualRepoConfig.update(actualStandaloneConfig);
+        TestUtil.compareRepoConfig(expectedRepoConfig, actualRepoConfig);
+    }
+}

src/test/java/reposense/util/TestUtil.java

@@ -10,6 +10,7 @@
 
 import org.junit.Assert;
 
+import reposense.model.Author;
 import reposense.model.RepoConfiguration;
 
 public class TestUtil {
@@ -114,6 +115,24 @@ public static void compareRepoConfig(RepoConfiguration expectedRepoConfig, RepoC
                 expectedRepoConfig.getAuthorAliasMap().hashCode(), actualRepoConfig.getAuthorAliasMap().hashCode());
         Assert.assertEquals(expectedRepoConfig.getIgnoreGlobList(), actualRepoConfig.getIgnoreGlobList());
         Assert.assertEquals(expectedRepoConfig.getFormats(), actualRepoConfig.getFormats());
+
+        for (int i = 0; i < expectedRepoConfig.getAuthorList().size(); i++) {
+            compareAuthor(expectedRepoConfig.getAuthorList().get(i), actualRepoConfig.getAuthorList().get(i));
+        }
+    }
+
+    /**
+     * Compares attributes of {@code expectedAuthor} and {@code actualAuthor}, with exception of it's display name.
+     *
+     * The display name is not compared as it varies with object construction.
+     * It is a transient value and it is not needed for object matching.
+     *
+     * @throws AssertionError if any attributes fail equality check.
+     */
+    public static void compareAuthor(Author expectedAuthor, Author actualAuthor) {
+        Assert.assertEquals(expectedAuthor.getGitId(), actualAuthor.getGitId());
+        Assert.assertEquals(expectedAuthor.getIgnoreGlobList(), actualAuthor.getIgnoreGlobList());
+        Assert.assertEquals(expectedAuthor.getAuthorAliases(), actualAuthor.getAuthorAliases());
     }
 
     /**

src/test/resources/StandaloneConfigJsonParserTest/standaloneConfig_emptyJson.json

@@ -0,0 +1,3 @@
+{
+
+}

src/test/resources/StandaloneConfigJsonParserTest/standaloneConfig_emptyText.json

@@ -0,0 +1 @@
+

src/test/resources/StandaloneConfigJsonParserTest/standaloneConfig_full.json

@@ -0,0 +1,14 @@
+{
+	"ignoreGlobList": ["**.adoc", "collate**"],
+	"formats": ["gradle", "jade", "java", "js", "md", "scss", "yml"],
+	"ignoreCommitList": ["7b96c563eb2d3612aa5275364333664a18f01491"],
+	"authors":
+	[
+		{
+			"githubId": "yong24s",
+			"displayName": "Yong Hao",
+			"authorNames": ["Yong Hao TENG"],
+			"ignoreGlobList": ["**.css", "**.html", "**.jade", "**.js"]
+		}
+	]
+}

src/test/resources/StandaloneConfigJsonParserTest/standaloneConfig_githubId_only.json

@@ -0,0 +1,8 @@
+{
+  "authors":
+  [
+    {
+      "githubId": "yong24s"
+    }
+  ]
+}

src/test/resources/StandaloneConfigJsonParserTest/standaloneConfig_malformedJson.json

@@ -0,0 +1,7 @@
+{
+  "authors":
+  [
+    {
+      "githubId": "yong24s"
+    },
+  ]

src/test/resources/StandaloneConfigJsonParserTest/standaloneConfig_unknownPropertyInJson.json

@@ -0,0 +1,9 @@
+{
+  "authors":
+  [
+    {
+      "githubId": "yong24s",
+      "level": "1"
+    },
+  ]
+}