Add tests & Fix NullPointerException

Fix NullPointerException when no arguments are provided to a Function or a Term.

Author: QuickWrite

src/main/java/net/quickwrite/fluent4j/ast/placeable/base/FluentFunction.java

@@ -27,7 +27,7 @@ public FluentFunction(final String functionName, final FluentArgs arguments) {
             throw new FluentParseException("The callee has to be an upper-case identifier or a term");
         }
 
-        this.arguments = arguments;
+        this.arguments = arguments != null ? arguments : FluentArgs.EMPTY_ARGS;
     }
 
     /**

src/test/java/net/quickwrite/fluent4j/TestReferenceExpressions.java

@@ -0,0 +1,62 @@
+package net.quickwrite.fluent4j;
+
+import net.quickwrite.fluent4j.builder.FluentArgsBuilder;
+import net.quickwrite.fluent4j.util.bundle.FluentBundle;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.jupiter.api.Assertions;
+
+import java.io.IOException;
+
+public class TestReferenceExpressions {
+    private FluentBundle bundle;
+
+    @Before
+    public void setUp() throws IOException {
+        this.bundle = GetFileHelper.getFluentBundle("reference_expressions.ftl");
+    }
+
+    @Test
+    public void testIfExceptions() {
+        Assertions.assertTrue(bundle.hasExceptions());
+    }
+
+    @Test
+    public void testMessageReferencePlaceable() {
+        Assertions.assertEquals("{msg}", GetFileHelper.getMessage(bundle, "message-reference-placeable"));
+    }
+
+    @Test
+    public void testTermReferencePlaceable() {
+        Assertions.assertEquals("{-term}", GetFileHelper.getMessage(bundle, "term-reference-placeable"));
+    }
+
+    @Test
+    public void testVariableReferencePlaceable() {
+        Assertions.assertEquals("{$var}", GetFileHelper.getMessage(bundle, "variable-reference-placeable"));
+    }
+
+    @Test
+    public void testVariableReferenceSelector() {
+        Assertions.assertEquals("Value", GetFileHelper.getMessage(bundle, "variable-reference-selector"));
+    }
+
+    @Test
+    public void testValidMessageReferencePlaceable() {
+        Assertions.assertEquals("Valid Message", GetFileHelper.getMessage(bundle, "valid-message-reference-placeable"));
+    }
+
+    @Test
+    public void testValidTermReferencePlaceable() {
+        Assertions.assertEquals("Valid Term", GetFileHelper.getMessage(bundle, "valid-term-reference-placeable"));
+    }
+
+    @Test
+    public void testValidVariableReferencePlaceable() {
+        Assertions.assertEquals("Value",
+                bundle.getMessage("valid-variable-reference-placeable",
+                    new FluentArgsBuilder().set("var", "Value").build()
+                ).orElseThrow()
+        );
+    }
+}

src/test/java/net/quickwrite/fluent4j/TestSelectExpressions.java

@@ -0,0 +1,47 @@
+package net.quickwrite.fluent4j;
+
+import net.quickwrite.fluent4j.util.bundle.FluentBundle;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.jupiter.api.Assertions;
+
+import java.io.IOException;
+
+public class TestSelectExpressions {
+    private FluentBundle bundle;
+
+    @Before
+    public void setUp() throws IOException {
+        this.bundle = GetFileHelper.getFluentBundle("select_expressions.ftl");
+    }
+
+    @Test
+    public void testIfExceptions() {
+        Assertions.assertTrue(bundle.hasExceptions());
+    }
+
+    @Test
+    public void testNewMessages() {
+        Assertions.assertEquals("Other", GetFileHelper.getMessage(bundle, "new-messages"));
+    }
+
+    @Test
+    public void testValidSelectorTermAttribute() {
+        Assertions.assertEquals("Value", GetFileHelper.getMessage(bundle, "valid-selector-term-attribute"));
+    }
+
+    @Test
+    public void testEmptyVariant() {
+        Assertions.assertEquals("", GetFileHelper.getMessage(bundle, "empty-variant"));
+    }
+
+    @Test
+    public void testReducedWhitespace() {
+        Assertions.assertEquals("", GetFileHelper.getMessage(bundle, "reduced-whitespace"));
+    }
+
+    @Test
+    public void testNestedSelect() {
+        Assertions.assertEquals("Value", GetFileHelper.getMessage(bundle, "nested-select"));
+    }
+}

src/test/java/net/quickwrite/fluent4j/TestSparseEntries.java

@@ -0,0 +1,55 @@
+package net.quickwrite.fluent4j;
+
+import net.quickwrite.fluent4j.util.bundle.FluentBundle;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.jupiter.api.Assertions;
+
+import java.io.IOException;
+
+public class TestSparseEntries {
+    private FluentBundle bundle;
+
+    @Before
+    public void setUp() throws IOException {
+        this.bundle = GetFileHelper.getFluentBundle("sparse_entries.ftl");
+    }
+
+    @Test
+    public void testIfExceptions() {
+        Assertions.assertFalse(bundle.hasExceptions());
+    }
+
+    @Test
+    public void testKey01() {
+        Assertions.assertEquals("Value", GetFileHelper.getMessage(bundle, "key01"));
+    }
+
+    @Test
+    public void testKey02() {
+        Assertions.assertEquals("", GetFileHelper.getMessage(bundle, "key02"));
+    }
+
+    @Test
+    public void testKey03() {
+        Assertions.assertEquals("""
+                Value
+                Continued
+                
+                
+                Over multiple
+                Lines""",
+                GetFileHelper.getMessage(bundle, "key03")
+        );
+    }
+
+    @Test
+    public void testKey05() {
+        Assertions.assertEquals("Value", GetFileHelper.getMessage(bundle, "key05"));
+    }
+
+    @Test
+    public void testKey06() {
+        Assertions.assertEquals("One", GetFileHelper.getMessage(bundle, "key06"));
+    }
+}

src/test/java/net/quickwrite/fluent4j/TestTab.java

@@ -0,0 +1,37 @@
+package net.quickwrite.fluent4j;
+
+import net.quickwrite.fluent4j.util.bundle.FluentBundle;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.jupiter.api.Assertions;
+
+import java.io.IOException;
+
+public class TestTab {
+    private FluentBundle bundle;
+
+    @Before
+    public void setUp() throws IOException {
+        this.bundle = GetFileHelper.getFluentBundle("tab.ftl");
+    }
+
+    @Test
+    public void testIfExceptions() {
+        Assertions.assertTrue(bundle.hasExceptions());
+    }
+
+    @Test
+    public void testKey01() {
+        Assertions.assertEquals("\tValue 01", GetFileHelper.getMessage(bundle, "key01"));
+    }
+
+    @Test
+    public void testKey03() {
+        Assertions.assertEquals("", GetFileHelper.getMessage(bundle, "key03"));
+    }
+
+    @Test
+    public void testKey04() {
+        Assertions.assertEquals("This line is indented by 4 spaces,", GetFileHelper.getMessage(bundle, "key04"));
+    }
+}

src/test/java/net/quickwrite/fluent4j/TestTermParameters.java

@@ -0,0 +1,42 @@
+package net.quickwrite.fluent4j;
+
+import net.quickwrite.fluent4j.util.bundle.FluentBundle;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.jupiter.api.Assertions;
+
+import java.io.IOException;
+
+public class TestTermParameters {
+    private FluentBundle bundle;
+
+    @Before
+    public void setUp() throws IOException {
+        this.bundle = GetFileHelper.getFluentBundle("term_parameters.ftl");
+    }
+
+    @Test
+    public void testIfExceptions() {
+        Assertions.assertFalse(bundle.hasExceptions());
+    }
+
+    @Test
+    public void testKey01() {
+        Assertions.assertEquals("Value", GetFileHelper.getMessage(bundle, "key01"));
+    }
+
+    @Test
+    public void testKey02() {
+        Assertions.assertEquals("Value", GetFileHelper.getMessage(bundle, "key02"));
+    }
+
+    @Test
+    public void testKey03() {
+        Assertions.assertEquals("Value", GetFileHelper.getMessage(bundle, "key03"));
+    }
+
+    @Test
+    public void testKey04() {
+        Assertions.assertEquals("Value", GetFileHelper.getMessage(bundle, "key04"));
+    }
+}

src/test/resources/input/placeables.ftl

@@ -4,11 +4,6 @@ message-reference-placeable = {msg}
 term-reference-placeable = {-term}
 variable-reference-placeable = {$var}
 
-# Function references are invalid outside of call expressions.
-# This parses as a valid MessageReference.
-function-reference-placeable = {FUN}
-
-
 ## Reference expressions in selectors.
 
 variable-reference-selector = {$var ->
@@ -23,8 +18,11 @@ message-reference-selector = {msg ->
 term-reference-selector = {-term ->
    *[key] Value
 }
-# ERROR Function references are invalid outside of call expressions, and this
-# parses as a MessageReference which isn't a valid selector.
-function-expression-selector = {FUN ->
-   *[key] Value
-}
+
+## Check if valid references work
+valid-message-reference-placeable = {valid-msg}
+valid-term-reference-placeable = {-valid-term}
+valid-variable-reference-placeable = {$var}
+
+valid-msg = Valid Message
+-valid-term = Valid Term

src/test/resources/input/reference_expressions.ftl

@@ -6,33 +6,19 @@ new-messages =
 
 valid-selector-term-attribute =
     { -term.case ->
-       *[key] value
+       *[key] Value
     }
 
 # ERROR Term values are not valid selectors
 invalid-selector-term-value =
     { -term ->
-       *[key] value
+       *[key] Value
     }
 
 # ERROR CallExpressions on Terms are similar to TermReferences
 invalid-selector-term-variant =
     { -term(case: "nominative") ->
-       *[key] value
-    }
-
-# ERROR Nested expressions are not valid selectors
-invalid-selector-nested-expression =
-    { { 3 } ->
-        *[key] default
-    }
-
-# ERROR Select expressions are not valid selectors
-invalid-selector-select-expression =
-    { { $sel ->
-        *[key] value
-        } ->
-        *[key] default
+       *[key] Value
     }
 
 empty-variant =