feat: add support for non-standard JSON shapes via mapProp

README.md

@@ -75,6 +75,48 @@ const Example = () => {
 };
 ```
 
+### Other JSON shapes
+
+If your data doesn't follow the `type` | `props` shape, `react-from-json` makes it easy to map your data on the fly using the `mapProp` prop.
+
+```jsx
+import React from "react";
+import ReactFromJSON from "react-from-json";
+import mapping from "./mapping";
+
+const entryWithDifferentShape = {
+  _type: "Burger",
+  chain: "Wahlburger",
+  children: {
+    _type: "Patty",
+    variant: "Impossible"
+  }
+};
+
+const mapProp = prop => {
+  if (prop._type) {
+    const { _type, ...props } = prop;
+
+    return {
+      type: _type,
+      props
+    };
+  }
+
+  return prop;
+};
+
+const Example = () => {
+  return (
+    <ReactFromJSON
+      entry={entryWithDifferentShape}
+      mapping={mapping}
+      mapProp={mapProp}
+    />
+  );
+};
+```
+
 ### Flat trees
 
 `react-from-json` also supports flat, non-recursive structures via the special `<ComponentLookup />` component. This is useful when working with typed systems like GraphQL, and you need to avoid unions.

src/__helpers__/data.ts

@@ -41,6 +41,34 @@ export const recursiveEntry = {
   }
 };
 
+export const entryWithDifferentShape = {
+  _type: "Burger",
+  chain: "Wahlburger",
+  bun: {
+    _type: "Bun",
+    variant: "sesame"
+  },
+  cheese: true,
+  children: [
+    {
+      _type: "Patty",
+      size: "large",
+      ingredient: {
+        _type: "PattyIngredient",
+        variant: "impossible"
+      }
+    },
+    {
+      _type: "Patty",
+      size: "large",
+      ingredient: {
+        _type: "PattyIngredient",
+        variant: "beef"
+      }
+    }
+  ]
+};
+
 export const flatEntry = {
   type: "Burger",
   props: {

src/__tests__/__snapshots__/index.tsx.snap

@@ -89,3 +89,48 @@ exports[`ReactFromJSON to render a recursive entry 1`] = `
   </div>
 </div>
 `;
+
+exports[`ReactFromJSON to render a recursive entry with a non-standard shape 1`] = `
+<div>
+  <div />
+  <div>
+    <div>
+      <div />
+      sesame bun
+    </div>
+  </div>
+  <div>
+    cheese
+  </div>
+  <div>
+    <div
+      id="undefined"
+    >
+      <div>
+        0
+      </div>
+      large patty
+      <div>
+        impossible
+      </div>
+    </div>
+    <div
+      id="undefined"
+    >
+      <div>
+        Order: 1
+      </div>
+      large patty
+      <div>
+        beef
+      </div>
+    </div>
+  </div>
+  <div>
+    <div>
+      <div />
+      sesame bun
+    </div>
+  </div>
+</div>
+`;

src/__tests__/index.tsx

@@ -6,6 +6,7 @@ import { Mapping, Components } from "../__helpers__/interfaces";
 import {
   mapping,
   recursiveEntry,
+  entryWithDifferentShape,
   flatEntry,
   flatComponents
 } from "../__helpers__/data";
@@ -25,6 +26,31 @@ describe("ReactFromJSON", () => {
     expect(tree).toMatchSnapshot();
   });
 
+  it("to render a recursive entry with a non-standard shape", () => {
+    const tree = renderer
+      .create(
+        <BurgerReactFromJSON
+          entry={entryWithDifferentShape}
+          mapping={mapping}
+          mapProp={prop => {
+            if (prop._type) {
+              const { _type, ...props } = prop;
+
+              return {
+                type: _type,
+                props
+              };
+            }
+
+            return prop;
+          }}
+        />
+      )
+      .toJSON();
+
+    expect(tree).toMatchSnapshot();
+  });
+
   it("to render a flat entry with a components attribute", () => {
     const tree = renderer
       .create(

src/index.tsx

@@ -20,7 +20,8 @@ export interface ReactFromJSONProps<
   ComponentsType = object
 > {
   components?: ComponentsType;
-  entry: Component;
+  entry: Component | any;
+  mapProp?: (obj: any) => any;
   mapping: MappingType;
 }
 
@@ -71,23 +72,26 @@ class ReactFromJSON<
   };
 
   resolveProp = (prop: any, index?: number): any => {
-    if (prop === null) {
-      return prop;
-    } else if (Array.isArray(prop)) {
-      return prop.map(this.resolveProp);
-    } else if (typeof prop === "object") {
+    const { mapProp = (p: any) => p } = this.props;
+    const mappedProp = mapProp(prop);
+
+    if (mappedProp === null) {
+      return mappedProp;
+    } else if (Array.isArray(mappedProp)) {
+      return mappedProp.map(this.resolveProp);
+    } else if (typeof mappedProp === "object") {
       if (
         // Typeguard
-        prop["type"] !== undefined &&
-        prop["props"] !== undefined
+        mappedProp["type"] !== undefined &&
+        mappedProp["props"] !== undefined
       ) {
-        const component: Component = prop;
+        const component: Component = mappedProp;
 
         return this.renderComponent(component, index);
       }
     }
 
-    return prop;
+    return mappedProp;
   };
 
   getNextKey(type: string, propIndex?: number) {
@@ -97,7 +101,7 @@ class ReactFromJSON<
     return `${type}_${this.counter[type]++}${propIndexKey}`;
   }
 
-  renderComponent(component: Component, propIndex?: number) {
+  renderComponent(component: Component | any, propIndex?: number) {
     const { mapping } = this.props;
     const { type, props } = component;
     const resolvedProps = {};
@@ -126,7 +130,7 @@ class ReactFromJSON<
   render() {
     const { entry } = this.props;
 
-    return <>{this.renderComponent(entry)}</>;
+    return <>{this.resolveProp(entry)}</>;
   }
 }