Fixed array of union type - added parentheses

Author: vojtechhabarta

typescript-generator-core/src/main/java/cz/habarta/typescript/generator/TsType.java

@@ -119,7 +119,11 @@ public BasicArrayType(TsType elementType) {
 
         @Override
         public String format(Settings settings) {
-            return elementType.format(settings) + "[]";
+            // https://github.com/Microsoft/TypeScript/pull/914
+            // TypeScript Specification A.1
+            return elementType instanceof UnionType
+                    ? "(" + elementType.format(settings) + ")" + "[]"
+                    : elementType.format(settings) + "[]";
         }
 
     }

typescript-generator-core/src/test/java/cz/habarta/typescript/generator/TsTypeTest.java

@@ -1,6 +1,8 @@
 package cz.habarta.typescript.generator;
 
+import static cz.habarta.typescript.generator.TsType.*;
 import cz.habarta.typescript.generator.compiler.Symbol;
+import java.util.Arrays;
 import static org.junit.Assert.*;
 
 import org.junit.*;
@@ -21,4 +23,15 @@ public void testNotEquals() {
     public void testNotEqualsNull() {
         assertNotEquals(new TsType.ReferenceType(new Symbol("Foo")), null);
     }
+
+    @Test
+    public void testTypeParentheses() {
+        final Settings settings = TestUtils.settings();
+        assertEquals("string | number", new UnionType(Arrays.asList(String, Number)).format(settings));
+        assertEquals("string | number[]", new UnionType(Arrays.asList(String, new BasicArrayType(Number))).format(settings));
+        assertEquals("(string | number)[]", new BasicArrayType(new UnionType(Arrays.asList(String, Number))).format(settings));
+        assertEquals("(string | number)[][]", new BasicArrayType(new BasicArrayType(new UnionType(Arrays.asList(String, Number)))).format(settings));
+        assertEquals("{ [index: string]: string | number }", new IndexedArrayType(String, new UnionType(Arrays.asList(String, Number))).format(settings));
+    }
+
 }