Implement display of Java default constructors

PsiClass does not include methods which are not present in the text
of the code. So when there are no constructors in a java class this
represents a class that only has a default constructor. The fix is
to create one for documentation.

2 files changed, 12 insertions, 5 deletions

diff --git a/core/src/main/kotlin/Java/JavaPsiDocumentationBuilder.kt b/core/src/main/kotlin/Java/JavaPsiDocumentationBuilder.kt
index 3b368329..d6743e60 100644
--- a/core/src/main/kotlin/Java/JavaPsiDocumentationBuilder.kt
+++ b/core/src/main/kotlin/Java/JavaPsiDocumentationBuilder.kt
@@ -29,7 +29,7 @@ fun getSignature(element: PsiElement?) = when(element) {
 }
 
 private fun methodSignature(method: PsiMethod): String {
-    return method.containingClass!!.qualifiedName + "$" + method.name + "(" +
+    return method.containingClass?.qualifiedName + "$" + method.name + "(" +
             method.parameterList.parameters.map { it.type.typeSignature() }.joinToString(",") + ")"
 }
 
@@ -167,7 +167,7 @@ class JavaPsiDocumentationBuilder : JavaDocumentationBuilder {
                         element.isInternal())
 
     private fun skipElementBySuppressedFiles(element: Any): Boolean =
-            element is PsiElement && element.containingFile.virtualFile.path in passConfiguration.suppressedFiles
+        element is PsiElement && element.containingFile.virtualFile?.path in passConfiguration.suppressedFiles
 
     private fun PsiElement.isInternal(): Boolean {
         val ktElement = (this as? KtLightElement<*, *>)?.kotlinOrigin ?: return false
@@ -196,8 +196,16 @@ class JavaPsiDocumentationBuilder : JavaDocumentationBuilder {
                 link(superClass, node, RefKind.Inheritor)
             }
         }
+        
+        var methodsAndConstructors = methods
+        if (constructors.isEmpty()) {
+            // Having no constructor represents a class that only has an implicit/default constructor
+            // so we create one synthetically for documentation
+            val factory = JavaPsiFacade.getElementFactory(this.project)
+            methodsAndConstructors += factory.createMethodFromText("public $name() {}", this)
+        }
         node.appendDetails(typeParameters) { build() }
-        node.appendMembers(methods) { build() }
+        node.appendMembers(methodsAndConstructors) { build() }
         node.appendMembers(fields) { build() }
         node.appendMembers(innerClasses) { build() }
         register(this, node)
diff --git a/core/src/test/kotlin/model/KotlinAsJavaTest.kt b/core/src/test/kotlin/model/KotlinAsJavaTest.kt
index 8249dd0f..c29776be 100644
--- a/core/src/test/kotlin/model/KotlinAsJavaTest.kt
+++ b/core/src/test/kotlin/model/KotlinAsJavaTest.kt
@@ -16,9 +16,8 @@ class KotlinAsJavaTest {
             val facadeClass = pkg.members.single { it.name == "FunctionKt" }
             assertEquals(NodeKind.Class, facadeClass.kind)
 
-            val fn = facadeClass.members.single()
+            val fn = facadeClass.members.single { it.kind == NodeKind.Function}
             assertEquals("fn", fn.name)
-            assertEquals(NodeKind.Function, fn.kind)
         }
     }