Fixed an exception when logging unserializable errors

Reviewed By: nikoant

Differential Revision: D33276412

fbshipit-source-id: 615b2cc523a3ab4445a1208f460753b8634f6812

desktop/flipper-plugin/src/__tests__/api.node.tsx

@@ -59,6 +59,7 @@ test('Correct top level API exposed', () => {
       "path",
       "produce",
       "renderReactRoot",
+      "safeStringify",
       "sleep",
       "styled",
       "textContent",

desktop/flipper-plugin/src/index.ts

@@ -134,6 +134,7 @@ export {textContent} from './utils/textContent';
 import * as path from './utils/path';
 export {path};
 export * from './utils/uuid';
+export {safeStringify} from './utils/safeStringify';
 
 // It's not ideal that this exists in flipper-plugin sources directly,
 // but is the least pain for plugin authors.

docs/extending/flipper-plugin.mdx

@@ -1166,6 +1166,12 @@ Usage: `uuid()`
 
 Returns UUID V4.
 
+### safeStringify
+
+Usage: `safeStringify(dataStructure)`
+
+Serialises the given data structure using `JSON.stringify`, but doesn't throw if the processes failed, but rather returns a `<unserializable ...>` string.
+
 ## TestUtils
 
 The object `TestUtils` as exposed from `flipper-plugin` exposes utilities to write unit tests for Sandy plugins.