Props extended from Pick fails - #22 fixed

package.json

@@ -1,6 +1,6 @@
 {
   "name": "react-docgen-typescript",
-  "version": "1.0.1",
+  "version": "1.0.2",
   "description": "",
   "main": "lib/index.js",
   "scripts": {

src/__tests__/data/ColumnWithPick.tsx

@@ -0,0 +1,34 @@
+import * as React from 'react';
+
+/**
+ * Column properties.
+ */
+export interface ManyProps {
+    /** prop1 description */
+    prop1?: string;
+    /** prop2 description */
+    prop2: number;
+    /**
+     * prop3 description
+     */
+    prop3: () => void;
+    /** prop4 description */
+    prop4: 'option1' | 'option2' | "option3";
+}
+
+export interface ColumnProps extends Pick<ManyProps, 'prop1' | 'prop2'> {
+    /** propx description */
+    propx: number;
+}
+
+/**
+ * Column description
+ */
+export class Column extends React.Component<ColumnProps, {}> {
+    render() {
+        const {prop1} = this.props;
+        return <div>{prop1}</div>;
+    }
+}
+
+export default Column;

src/__tests__/parser.ts

@@ -26,6 +26,18 @@ describe('parser', () => {
         });
     });
 
+    it('should parse simple react class component with picked properties', function() {
+        // we are not able to get correct descriptions for prop1,prop2
+        check('ColumnWithPick', {
+            Column: {
+                children,
+                prop1: { type: 'string', required: false, description: '' },
+                prop2: { type: 'number', description: '' },
+                propx: { type: 'number' },
+            }
+        });
+    });
+
     it('should parse HOCs', function() {
         check('ColumnHigherOrderComponent', {
             ColumnHigherOrderComponent1: {

src/parser.ts

@@ -222,6 +222,11 @@ class Parser {
      */
     getFullJsDocComment(symbol: ts.Symbol) {
 
+        // in some cases this can be undefined (Pick<Type, 'prop1'|'prop2'>)
+        if (symbol.getDocumentationComment === undefined) {
+            return "";
+        }
+
         const mainComment = ts.displayPartsToString(symbol.getDocumentationComment());
 
         const tags = symbol.getJsDocTags() || [];