Render external symbols in snapshots

Amp-Thread-ID: https://ampcode.com/threads/T-01a029e2-5095-710a-9cce-0c6d8645c173

Author: eseliger

snapshots/input/react/src/LoaderInput.tsx

@@ -1,3 +1,5 @@
+// format-options: showExternalSymbols
+
 import React from 'react'
 
 /** Takes loading prop, input component as child */

snapshots/output/react/src/LoaderInput.tsx

@@ -1,9 +1,13 @@
 // language TypeScriptReact
 // < definition react-example 1.0.0 src/`LoaderInput.tsx`/
 
+// format-options: showExternalSymbols
+
 import React from 'react'
 //     ^^^^^ reference @types/react 19.2.18 `index.d.ts`/React/
+//     external SymbolInformation @types/react 19.2.18 `index.d.ts`/React/
 //                ^^^^^^^ reference @types/react 19.2.18 `index.d.ts`/
+//                external SymbolInformation @types/react 19.2.18 `index.d.ts`/
 
 /** Takes loading prop, input component as child */
 interface Props {
@@ -14,12 +18,14 @@ interface Props {
 //^^^^^^^^ definition react-example 1.0.0 src/`LoaderInput.tsx`/Props#children.
 //          ^^^^^ reference @types/react 19.2.18 `index.d.ts`/React/
 //                ^^^^^^^^^ reference @types/react 19.2.18 `index.d.ts`/React/ReactNode#
+//                external SymbolInformation @types/react 19.2.18 `index.d.ts`/React/ReactNode#
 }
 
 export const LoaderInput: React.FunctionComponent<Props> = ({
 //           ^^^^^^^^^^^ definition react-example 1.0.0 src/`LoaderInput.tsx`/LoaderInput.
 //                        ^^^^^ reference @types/react 19.2.18 `index.d.ts`/React/
 //                              ^^^^^^^^^^^^^^^^^ reference @types/react 19.2.18 `index.d.ts`/React/FunctionComponent#
+//                              external SymbolInformation @types/react 19.2.18 `index.d.ts`/React/FunctionComponent#
 //                                                ^^^^^ reference react-example 1.0.0 src/`LoaderInput.tsx`/Props#
   loading,
 //^^^^^^^ definition local 3
@@ -30,12 +36,15 @@ export const LoaderInput: React.FunctionComponent<Props> = ({
 }) => (
   <div className="hello">
 // ^^^ reference @types/react 19.2.18 `index.d.ts`/React/JSX/IntrinsicElements#div.
+// external SymbolInformation @types/react 19.2.18 `index.d.ts`/React/JSX/IntrinsicElements#div.
 //     ^^^^^^^^^ reference @types/react 19.2.18 `index.d.ts`/React/HTMLAttributes#className.
+//     external SymbolInformation @types/react 19.2.18 `index.d.ts`/React/HTMLAttributes#className.
     {children}
 //   ^^^^^^^^ reference local 4
     {loading && <p>spinner</p>}
 //   ^^^^^^^ reference local 3
 //               ^ reference @types/react 19.2.18 `index.d.ts`/React/JSX/IntrinsicElements#p.
+//               external SymbolInformation @types/react 19.2.18 `index.d.ts`/React/JSX/IntrinsicElements#p.
 //                          ^ reference @types/react 19.2.18 `index.d.ts`/React/JSX/IntrinsicElements#p.
   </div>
 //  ^^^ reference @types/react 19.2.18 `index.d.ts`/React/JSX/IntrinsicElements#div.
@@ -51,6 +60,7 @@ export const LoaderInput2: React.FunctionComponent<Props> = props => {
 //        ^^^^^^^^^^^ reference react-example 1.0.0 src/`LoaderInput.tsx`/LoaderInput.
 //                    ^^^^^^^ reference react-example 1.0.0 src/`LoaderInput.tsx`/Props#loading.
 //                                   ^^^ reference @types/react 19.2.18 `index.d.ts`/React/Attributes#key.
+//                                   external SymbolInformation @types/react 19.2.18 `index.d.ts`/React/Attributes#key.
 //                                             ^^^^^^^^ reference react-example 1.0.0 src/`LoaderInput.tsx`/Props#children.
 //                                                       ^^^^^ reference local 6
 //                                                             ^^^^^^^^ reference react-example 1.0.0 src/`LoaderInput.tsx`/Props#children.

src/SnapshotTesting.ts

@@ -18,11 +18,13 @@ function getSymbolTable(
 
 function parseOptions(lines: string[]): {
   showDocs: boolean
+  showExternalSymbols: boolean
   showKinds: boolean
   showRanges: boolean
 } {
   const formatOptions = {
     showDocs: false,
+    showExternalSymbols: false,
     showKinds: false,
     showRanges: false,
   }
@@ -184,6 +186,10 @@ export function formatSnapshot(
 
     const externalSymbol = externalSymbolTable.get(symbol)
     if (externalSymbol) {
+      if (formatOptions.showExternalSymbols) {
+        out.push(prefix)
+        out.push(`external SymbolInformation ${symbolNameForSnapshot(symbol)}`)
+      }
       pushKind(externalSymbol.kind)
       pushOneDoc(externalSymbol.documentation, true)
       pushOneRelationship(externalSymbol.relationships)