Fix issue with negative numbers as default values (#69)

Author: dotcs

src/__tests__/data/ComponentWithDefaultProps.tsx

@@ -19,6 +19,8 @@ export interface IComponentWithDefaultPropsProps {
   sampleNull?: null;
   /** sampleUndefined description */
   sampleUndefined?: any;
+  /** sampleNumber description */
+  sampleNumber?: number;
 }
 
 /** ComponentWithDefaultProps description */
@@ -29,6 +31,7 @@ export class ComponentWithDefaultProps extends React.Component<
   static defaultProps: Partial<IComponentWithDefaultPropsProps> = {
     sampleFalse: false,
     sampleNull: null,
+    sampleNumber: -1,
     // prettier-ignore
     sampleObject: { a: '1', b: 2, c: true, d: false, e: undefined, f: null, g: { a: '1' } },
     sampleString: 'hello',

src/__tests__/parser.ts

@@ -190,6 +190,7 @@ describe('parser', () => {
           type: 'boolean'
         },
         sampleNull: { type: 'null', required: false, defaultValue: 'null' },
+        sampleNumber: { type: 'number', required: false, defaultValue: '-1' },
         sampleObject: {
           defaultValue: `{ a: '1', b: 2, c: true, d: false, e: undefined, f: null, g: { a: '1' } }`,
           required: false,

src/parser.ts

@@ -449,6 +449,8 @@ function getLiteralValueFromPropertyAssignment(
       return 'true';
     case ts.SyntaxKind.StringLiteral:
       return (initializer as ts.StringLiteral).text.trim();
+    case ts.SyntaxKind.PrefixUnaryExpression:
+      return initializer.getFullText().trim();
     case ts.SyntaxKind.NumericLiteral:
       return `${(initializer as ts.NumericLiteral).text}`;
     case ts.SyntaxKind.NullKeyword: