Fixes #8

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 2.0.1
+
+- FIX: Fixes [#8](https://github.com/asbjornh/view-models/issues/8) - `typescriptReact` parser crashing when parsing components with no arguments.
+
 ## 2.0.0
 
 - BREAKING: Changes the default file extension for generated TypeScript files from `.ts` to `.d.ts`

package.json

@@ -1,6 +1,6 @@
 {
   "name": "view-models",
-  "version": "2.0.0",
+  "version": "2.0.1",
   "description": "Generate viewmodels from react components",
   "main": "lib/index.js",
   "bin": {

source/parsers/prop-types/resolve-references.ts

@@ -3,6 +3,7 @@ import * as t from "@babel/types";
 
 import { MetaTypeTree } from "../../node-types";
 
+import first from "../../utils/first";
 import isObjectMethod from "../utils/is-object-method";
 import isMemberExpression from "../utils/is-member-expression";
 
@@ -29,7 +30,7 @@ export default function resolveReferences(
       >;
       const propName: string = propPath.node.key.name;
       const metaType = meta[propName] ? meta[propName].type : "";
-      const argument = path.node.arguments[0];
+      const argument = first(path.node.arguments);
 
       if (!argument) {
         throw new Error(
@@ -71,7 +72,7 @@ export default function resolveReferences(
       // Object.keys, Object.values
       else if (t.isCallExpression(argument) && isObjectMethod(argument)) {
         const objectMethod = argument;
-        const methodArg = objectMethod.arguments[0];
+        const methodArg = first(objectMethod.arguments);
 
         if (!methodArg) {
           throw new Error(

source/parsers/typescript-react/get-prop-types.ts

@@ -3,6 +3,7 @@ import * as t from "@babel/types";
 
 import getDefinitionName from "./get-definition-name";
 import filter from "../../utils/filter";
+import first from "../../utils/first";
 
 export default function getPropTypes(ast: t.File, componentName: string) {
   let typeName: string | undefined;
@@ -46,16 +47,16 @@ export default function getPropTypes(ast: t.File, componentName: string) {
       if (!t.isIdentifier(path.parent.id)) return;
       if (path.parent.id.name !== componentName) return;
 
-      const arg = path.node.params[0];
+      const firstArg = first(path.node.params);
 
-      if (t.isTSParameterProperty(arg))
+      if (t.isTSParameterProperty(firstArg))
         throw new Error(`Unexpected parameter property`);
 
-      if (t.isNoop(arg.typeAnnotation))
+      if (t.isNoop(firstArg?.typeAnnotation))
         throw new Error(`Unexpected noop in type annotation`);
 
-      if (arg.typeAnnotation) {
-        const argType = arg.typeAnnotation.typeAnnotation;
+      if (firstArg?.typeAnnotation) {
+        const argType = firstArg.typeAnnotation.typeAnnotation;
         if (t.isTSTypeReference(argType)) {
           const name = getDefinitionName(argType.typeName);
           types = typeDeclarations[name];
@@ -76,7 +77,7 @@ export default function getPropTypes(ast: t.File, componentName: string) {
       if (!t.isTSTypeReference(funcType)) return;
 
       if (funcType.typeParameters !== null) {
-        const type = funcType.typeParameters.params[0];
+        const type = first(funcType.typeParameters.params);
         if (t.isTSTypeReference(type)) {
           const name = getDefinitionName(type.typeName);
           types = typeDeclarations[name];

source/parsers/typescript-react/typescript-react.test.js

@@ -33,6 +33,17 @@ test(
   classes.funcComponent
 );
 
+test(
+  "Component without props argument",
+  template,
+  `const Component: React.FunctionComponent<{}> = () => null;
+  export default Component;`,
+  `${csharpImports}
+  public class Component
+  {
+  }`
+);
+
 test(
   "Empty component",
   template,

source/utils/first.ts

@@ -0,0 +1,4 @@
+/* Utility function for safely getting the first element of an array */
+export default function first<T>(arr: T[]): T | undefined {
+  return arr[0];
+}